Uh oh….. you’ve got a period lath and plaster ceiling that needs some ‘love’ hmm? I’ve been working with lath and plaster for more than 30 years so read on and learn what you can do to get years more life out of your plasterwork and what to do if it’s beyond economic repair. (p.s. if you want to remove your lath and plaster ceiling, you can head over to the “How to Take Down Lath and Plaster Ceilings” page instead). Most people agree that traditional lath and plaster ceilings (and walls), really add charm and enhance the feeling of living in a period house. Eventually though, old lath & plaster is prone to cracking, sagging or even falling down. The good news is that it’s often possible to repair lath & plaster ceilings (and walls) and make them last a good while longer (if you like the look and feel). For those that have gone too far and need replacing with something else, we’ll look at the different options open to you. What you choose depends on the look or feel you’re aiming for, your budget and your ‘tolerance’ of erm…..how can I put it; ‘rustic’ surfaces! It’s also a universal truth that the ‘flatter’ and most ‘long lived’ repairs cost more to carry out and the older your lath and plaster, the more work it’s likely to need.
OK, enough blurb, lets get started……
Here are the Top Ten Eleven Ways to Repair Lath and Plaster Ceilings and Walls
Pretty much in order of cost/complexity/longevity…….
-
Re-decorate the Plasterwork As It Is
The most minimum work, arguably not even a repair but basic maintenance. Vacuum to remove dust, (wash down, if required) and then re-decorate, preferably with a lime based paint (if the ceiling is completely original) or most likely with suitable water based paint. Not a good repair if the plasterwork has gone beyond the cracking stage, i.e. sagging badly, so this depends on the plasterworks condition.
- Cost: Very economical and quick.
- Pros: Period charm in abundance. Ideal for very old cottages that don’t have a straight edge or surface in them. Shows imperfections.
- Cons: Possibly very short term solution for damaged plasterwork and even potentially dangerous if really bad! Not a ‘flat’ finish. Shows imperfections!
-
Repairing Cracks in Lath and Plaster (Ceilings and Walls)
If the plasterwork has cracked or crazed but is still firmly adhered to the laths then you could simply fill the cracks and blemishes and redecorate. First scrape out all cracks and vacuum out loose material. Prime the cracks with a suitable primer like unibond then fill cracks and small blemishes with decorators’ filler using a suitably sized scraper or drywall spreader. Push the filler in at 90 degrees to the crack and then press to flatten out and scrape off excess by running the scraper along the crack. Gently sand the filler flat if necessary (shouldn’t need much) and vacuum all dust away. Fine cracks could be filled with a flexible decorators caulk and smoothed over with a damp flexible scraper. Wash down if required and re-decorate.
- Cost: Economical repair.
- Pros: Retains period feel. Looks good initially. Easy and quick repair.
- Cons: Might only last a few years depending on plasterworks original condition.
-
Repairing Loose and Small Sections of Missing Plaster
Small areas of missing or loose plasterwork can be re-plastered, preferably using similar haired lime based mortars and plasters. If these are not available to you, then areas could be re-plastered using modern lightweight backing plasters and finish plaster (non protected ceilings only). Ensure that loose plaster and dust is removed and damp the area a little before re-plastering. Ask at your local builders merchant for suitable plasters.
- Cost: Economical to medium repair depending on size of area.
- Pros: Retains period feel. Fairly quick repair.
- Cons: Needs reasonable DIY Skills. modern plasters might be too ‘rigid’ alongside your old plaster leading to some cracking. Might only last a few years depending on the surrounding plasterworks condition.
NOTE: It is popular to see folks recommending to completely ‘re-skim’ old plasterwork with a thin ‘veneer’ of modern gypsum based plaster, say 3 or 4mm thick. Whilst this can tighten up the plasterwork on an old wall, it can cause cracking later due to the relative stiffness of the new plaster in comparison to the underlying lath and plasterwork. Sorry!
-
Using a Thick Lining Paper
A sound (ish!) lath and plaster ceilings appearance can be improved greatly by the use of a good quality, thick lining paper. Lining paper has the benefit of ‘tightening’ everything up and giving the ceiling an uniform look. It can then be decorated however you wish (ironically, some are painted to look ‘distressed’!?!). It can be a good idea to scrape out and fill cracks as No.2 before you glue a thick grade of decorating lining paper over the plasterwork, as lining paper will ‘shrink’ into any cracks and unevenness. Re-decorate as you wish.
- Cost: Reasonably economical repair.
- Pros: Retains period feel. Could gain many more years out of reasonable plasterwork.
- Cons: Relatively difficult on uneven surfaces. Won’t stop further cracking over time if surface is still moving.
-
Using a ‘Glue’ System to Fix Sagging Plasterwork
Plasterwork can be ‘glued’ back into place by drilling holes in the plasterwork, vacuuming out the dust and injecting a suitable tube type adhesive. The plasterwork is then gently pushed back into place and supported until the adhesive dries. There is even a ‘system’ available in the states called “Big Wallys Plaster Magic“, or you can see an video that explains the principles here:- Gluing lath and plaster. A popular way is to drill 4mm holes, slightly countersink the holes, vacuum then squirt a thin adhesive into the hole followed by the drywall screw. Gently tighten the screw up into the countersunk plaster. Push up and support any sagging plasterwork first onto blanket covered lengths of timber gently wedged up to the ceiling. The guys at ‘Old House Online’ have a great artice that explains how to glue up a sagging ceiling perfectly… How to fix old ceilings with glue.
- Cost: Medium to high cost, depending on time taken and plasterwork condition.
- Pros: Medium term effectiveness. Retains period feel.
- Cons: Arguably a specialised job and may be too fiddly for some DIY repairers.
-
Removing the Whole Ceiling and Exposing the Existing Beams
Completely remove the lath and plaster, de-nail and clear away. Wire brush all plaster marks off the joists. Re-route any wiring, if required and repair any damage, holes in the timberwork etc. Clean up and vacuum all surfaces. Leave as is or decorate with varnish, wood stain, or paint. Often strips of plasterboard are fixed in between the joists on small lathes nailed onto the side of the joists to hide wiring and the underside of the floorboards above. Usually just used on ceilings (walls sometimes in the USA due to better sawn lath).
- Cost: Economical to medium depending on timberwork condition.
- Pros: All the old plasterwork is removed and finished with newly decorated surfaces.
- Cons: Different look and feel, arguably only suited to certain properties and owners. Difficult electrical wiring and limited choice of light fittings.
-
Overboard with Plasterboard or Sheetrock
A lath and plaster ceiling can be left in place and ‘over-boarded’ with plasterboard, using long drywall screws through the existing lath and plaster into the joists (not ideal but, quite commonly done). You will hear this option discussed a lot and for many it is considered the ‘only’ option, mostly to avoid the horrible mess created by complete removal!
- First you need to find what there is to fix your new plasterboards too. Usually ceiling joists or studs in a wall.
- Find them using the old way of drilling a line of holes 20mm (3/4″) apart where you suspect there is timber. You will feel the resistance when you hit wood, mark it and continue to find the other side of the wood.
- Now you know how wide the wood is and where it is.
- Next Mark their position on the wall, about 25mm down from the ceiling.
- Now you are ready to over-board with plasterboard (sheetrock) using long (60mm to 75mm) drywall screws into the timberwork where you have marked.
- Board joints are then taped and filled if tapered edge drywall is used or skimmed with finish plaster if square edged boards are used.
An even better way to overboard a ceiling or wall is to ‘batten out’ first. Here, appx 25mm x 50mm battens are fixed flat, underneath the existing lath and plasterwork, by screwing through it, into the existing ceiling joists. The battens could also be packed level/flat using thin plastic or timber ‘shims’ as they are screwed tight. Plasterboards are then fitted as normal, (often incorporating, new wiring, insulation and a vapour barrier). This becomes a good repair as the battens secure the old plasterwork and the plasterboard gives a ‘new’ finish, plus the convenience of easy cable runs for new lighting.
- Cost: Medium to high.
- Pros: Effectively a brand new surface is created out of plasterboard/sheetrock.
- Cons: Potential problems with adding additional weight or levels if there is a cornice. Loss of ceiling height. Loses that period feel.
-
Replacing the Plaster and Lath with Drywall/Plasterboard/Sheetrock
Completely remove the lath and plasterwork and replace with plasterboards / sheetrock. Once the existing ceiling is down and cleared away, mark the positions of all joists and timbers onto the walls. Then fix 12.5mm plasterboards to the underside of the original joists using 38mm drywall screws as normal. Use the marks on the walls to snap a chalk line onto the plasterboards, showing you where to place the screws. Board joints are then taped and filled if tapered edge boards are used, or skimmed with finish plaster if square edged boards are used.
- Cost: High. Removal of old material, new boards and finishing makes this one of the most expensive options.
- Pros: Plasterboards/sheetrock are stable and very flat. A permanent repair.
- Cons: Loses the period feel.
-
Re-plastering with Traditional Lime Mortar and Plaster
A rarer alternative to complete removal, is the removal of the sagging and broken plasterwork, repairing the existing laths (or replacing them) and re-plastering with a suitable two coat haired lime mortar and a third coat of lime finish plaster. You may need access to the top of the laths to clear away the ‘keys’ or mortar ‘snots’ that were pushed through the gaps in the lath the first time.
- Cost: High, due to special skills and materials needed.
- Pros: Good as new finish, that also matches the surrounding period work. Long term repair.
- Cons: Arguably not a DIY proposition due to work involving lime plasterwork.
-
Fully Repairing a ‘Protected’ Lath and Plaster Ceiling
Given enough time and money even the worst ceilings can be rescued, as you would have to do to satisfy the authorities if your ceilings were historically valuable. Briefly, fully support the plasterwork from underneath on blanket covered timber on props or staging. Working from above, gently remove all the accumulated dust, debris and old loose keys or nibs that build up over the decades or even centuries (dust masks essential!) Repairs can then be carried out using one of the various lath and plaster repair systems available. Often using stabilizing chemicals, wire mesh and adhesives or plasters, with the aim of reattaching the plasterwork below. For example; one system involves fixing a wire mesh to the inside edges of the joists just above the plasterwork and then applying adhesive to the plasterwork embedding it into the mesh.
- Cost: Expensive due to extreme care needed and labour involved.
- Pros: Retains all original period features. Usually only used on plasterwork of significant historical interest.
- Cons: Complicated, expensive, and sometimes beyond even the average builder. Arguably not a DIY proposition due to care needed to preserve original features without damage.
-
And That Just Leaves….Buy a Newer House.
Maybe you are just not cut out for living in a period house and would be better suited to a mimimalistic pad with the latest in smooooth technology…. *laughing*.
- Cost: Horribly expensive, removal companies, estate agents, lawyers etc.
- Pros: No lath and plaster to repair.
- Cons: Everything is very, very flat, smooth and arguably…..boring.
Need More Information or Help?
Urban legend has it that you only need to read six books on a subject to be classed as an ‘expert’. So, here are some books I found interesting which will be useful to get you started! Or drop me a comment and ask a question.
All available from amazon.co.uk, (or here at amazon.com for the rest of the world), just follow the links to have a peek!
A Practical Guide to Care and Repair, by Roger Hunt and Marianne Suhr. Hardback.
Don’t be deceived, this book may be at home on the coffee table, but it packs a lot of really useful information into its pages. Passed and approved by my favorite ‘Institute’, the guys at SPAB, the Society for the Protection of Ancient Buildings.
The book teaches you to work with your house, not fight it. Repair not restore or renovate. If you are into minimalism, white flat surfaces and recessed downlights, this book may be a shock for you, as it educates us to live with a buildings character, not destroy it.
maintenance of historic buildings
Maintenance of Historic Buildings
A Practical Handbook, by Jurgen Klemisch.
A practical, hands-on guide to the maintenance of your older house. Based on many years of experience, this book teaches you the current best practices related to maintenance and is presented using a straightforward logical format.
In two sections the book deals with maintenance for use by owners and how to conduct condition surveys. The book makes extensive use of helpful checklists, work cards detailing routine cleaning, deep cleaning, inspection, servicing and redecoration; and even spreadsheets to help plan your maintenance.
Following the books recommendations would also (over time) build a useful record about your house, which will be helpful when deciding the timing of future repairs and allow you to assess costs accurately.
A damp house is a dying house……
A Guide to the Causes and Treatment of Dampness, by Jonathan Hetreed. Hardback.
I thought that I would include this book because as the owner of an older property you will soon come to learn that water or damp is the mortal enemy of your house!
Managing the moisture and water, on, in and around your home is vital in the battle to preserve and protect it.
From the patio to the ridge, water is trying to get into your house and cause damage! Read Jonathan’s insights and learn how to keep it at bay.
The Victorian House manual from Haynes
The Victorian House Manual By Haynes
A no nonsense book that even Conservation Officers like and use! This book covers some of the most common problems found in houses built in this era, along with some of the more common misconceptions about some of the repairs commonly touted as being able to “cure all ills”.
As you would expect from Haynes these books have great photos and easy to understand and follow instructions. A hard to beat primer for anyone owning or thinking of buying a Victorian (or Edwardian for that matter) house.
Guide to using natural finishes
Lime and Clay Based Plasters, Renders and Paints – A Step-by-step Guide By Adam Weismann
Adam Weismann’s book is more specialized than those above and would suit the hard core enthusiast who wants to have a go at repairing their old walls and ceilings themselves.
Kevin McCloud from Grand Designs comments that it is “A splendid book. A real addition to what’s out there and very complementary to the Society for the Protection of Ancient Buildings’ new technical manual on Old Building Repairs”.
Disclaimer: The next three books are my own… forgive the plug 🙂
12 Ways to Fix Lath and Plaster Ceilings:
Complete Do-it-Yourself Guide for Homeowners, by Ian Anderson
Love them or hate them, I’ll show you what you can do with yours, based on over 30 years of on-site experience. I’ll show you how to evaluate the condition of your ceilings and quickly run through the options you have to repair and keep them.
Alternatively (and sadly); if needs must, I’ll show you how to safely remove them and install new ceilings, either with like for like traditional materials or more commonly, with modern drywall materials.
This complete homeowners guide includes:
- How to inspect and evaluate your lath and plaster ceiling.
- 7 ways to repair and keep your lath and plaster ceilings.
- 5 ways to replace your lath and plaster ceiling.
- Step by step guide to removing your lath and plaster ceiling.
- Levelling up your ceiling joists.
- Installing drywall.
- Further online resources.
Complete DIY Guide for Homeowners: 101 Ways to Properly Look After Your Home and Save Money, by Ian Anderson
Let’s be honest here, home maintenance has a huge image problem. It’s not cool, it’s not sexy and it definitely isn’t ever going to beat the thrill of building something new and shiny, not ever…
But guess what; you know that new and shiny thing you’re building instead of maintaining your home? Yup, it’s going to need maintaining to keep that new and shiny look you so desire.
So relax a little, surrender to it, and since you can’t truly escape it anyway, let a little maintenance creep into your life. Your stuff will love you for it; you will love your stuff for looking so good, and oh; the planet will quite like you for it too.
So, let me talk you into doing a little home maintenance…
How to be Handy [hairy bottom not required]
Build Money Saving DIY Skills, Create a Unique Home and Properly Look After Your Stuff, by Ian Anderson
Do you want to be handy and live a more practical life?
Then this book is for you. Because it’s a different kind of DIY book, one which will take you far beyond trying to blindly follow step-by-step instructions, to where you can stop faking it, and actually make it. To actually be practical; to be handy.
Using Ian’s simple R.E.L.E.A.R.N method you’ll ‘relearn’ how you look at DIY; to see the world through ‘practical eyes’. Relearn how you observe, listen, feel, and smell everything and what it all means. Plus, you’ll know how and where to find the information you need to fill any gaps and create workable solutions for your DIY projects.
You’ll learn how to use a few simple tools to easily transform your home, using your own head, hands, and heart to create something wonderful, fix something you treasure, maintain something you want to keep forever or build something just for fun.
There’s more than 30 years of experience from a professional builder and handyman, packed into this easy to follow method which explains how handy people like Ian tackle practical tasks, (especially the new and unknown), learning ‘just enough’ to get the job done.
Once you experience the physical world like a handy person does, you’ll think like a handy person and then you’ll be able to do anything. Seriously; anything you set your mind to…
Good luck with your own DIY endeavours and work safe.
Endnote….
Lath and plaster carpet
Carpet inspired by lath and plaster walling
Bev Hisey was so inspired by the look and feel of the lath and plaster when renovating her home that she has dedicated a brand new carpet design to it! Click the image to see more… Stay well Ian Anderson
Comments 70
You forgot a twelfth option: What about removing only the plaster and drywalling on top of the lathe??
Author
Hey Trace,
Yes, it certainly is an option and I’ve considered that in the past but to be honest, it’s a difficult option.
The main reason is the way lath are layered onto the average ceiling, especially in the UK (it’s possible that the often sawn lath in the USA lays flatter). This makes getting a properly flat ceiling difficult. Plus removing the plaster itself means a full cover down/ empty room anyway. Once you’re there, it’s just as easy to go the whole hog and take down the lath too.
Plus, most folks are upgrading lighting too and leaving the lath in place is more work for the electrician.
I hope that helps and thanks for making the time to comment 🙂
Merry Christmas,
Cheers
Ian
Hi Ian,
I love your help but my lath and plaster is in my 1924, hand painted dining room. The artist actually helped restore part of the DC Capital many years ago. I can’t simply repaint it. I can access the failing plaster from the living room. Should I put some glue in from the back? And what would you recommend?
Thank you,
Brenda
Hi Ian, I’ve just moved in to a Victorian house and the lathe and plaster ceilings have quite a few cracks in. We’ve experienced a lathe and plaster ceiling falling down in our last property so I’m a bit paranoid about it happening again. I’ve pressed the ceiling around the cracks and the plaster feels firm, no sagging or anything but I’m not sure what to do next to confirm they can be repaired rather than taking them down. Is there a way I can check them from under the floorboards above and what would I be looking for?
Is it possible to board over the lathe and plaster or is there still a risk it would all come down? Thanks
Author
Hi Jane,
Sorry for the delay, been away back to the UK for a long weekend!
Right, well you can definitely tell a lot by looking at the ceiling from above (see extract from my lath and plaster books about inspecting ceilings) you can also look at the cleaned up top whilst someone else gently pushes up from underneath.
If you do decide to board over the ceiling, I’d screw up some thin laths first, (maybe 19mm x 38mm tile lath is common) and then board onto the lath. Then there is no danger of the original ceiling coming down.
Here is the text about inspecting….
****INSPECTION
Working from a suitable, sturdy stepladder let’s properly inspect your ceiling, because only then can you properly evaluate its condition and answer the tough question, “Is this ceiling repairable or do I have to replace it?”
On a bright day, stand underneath one corner of your ceiling on your stepladder and with your head almost touching the ceiling look across the ceilings surface; do a 90-degree sweep (wall to wall), looking for cracks, sagging sections or unevenness, etc. Repeat from all four corners because the light hits the ceiling differently from each angle and might hide or highlight problems. It’s possible your ceiling looks quite flat from the floor, but once you get up close, you’ll get a much better idea of its condition. Feel free to hold up a 6’ (1.8m) long piece of straight wood or a plasterer’s straight edge to get a better idea of where any bumps and dips are (but don’t panic if it’s not flat, gentle undulations are quite normal, few things are flat in an older house).
Look out for one or more of the following…
• Thin hairline cracks in random patterns across the ceilings surface.
• Larger cracks with small missing pieces alongside.
• Bumps and other evidence of previous repairs over old cracks or damage.
• Patches of missing plasterwork, sometimes exposing areas of the lath (these will be obvious from the floor I know, duh!).
• Cracks around the edges of the room (wall to ceiling).
• Delaminated plaster, either in the thin finish coats or even through the base coats.
• Bellies or dips in the ceiling, caused by sagging areas of plasterwork (broken keys).
• Bellies across the whole ceiling caused by sagging joists (not always disastrous).
• Thick flaking layers of paint (on neglected ceilings).
Where you see cracks or sagging areas, stand underneath and gently push upwards with the palms of your hands. A tiny amount of give is normal, but if you can actually feel the plaster move up and down (often accompanied by a faint crunching or grinding noise), this means the plaster has separated from the laths (broken keys). A little dust and debris may fall from any cracks as you do this.
NOTE: Please, please, please don’t go crazy here! If you push and shove a badly damaged ceiling really hard, you might end up ‘wearing’ it, literally! Go gently my friend; you’re only trying to see if the plaster has separated from the lath, you’re not auditioning for a role in the next Avengers movie…
Another useful thing you can do on lower floors is to get someone (preferably a big chap!) to walk around upstairs whilst you watch the ceiling and especially any cracks for excessive movement. If there is a poor joist that’s flexing over a crack it’s going to be near impossible to repair, as it will just crack again because of the flexing load from above.
NOTE: If the joists are flexing because of damage (rot/insect/etc.), you’ll need to replace them. Either individually ‘one by one’, or by removing the whole floor if that’s an option. If the joists are flexing because they are undersized in a poorly constructed place, you’ll need to replace them with wider, stiffer ones or even deeper ones (if you have a little headroom to spare…).
IT’S ALL ABOUT THE KEYS
Plaster literally hangs underneath the laths from curls of plaster that have squeezed through gaps in between the laths. These curls, called keys (or sometimes nibs or snots) are vital to the integrity of the plasterwork. Lath nails rarely actually fail and it’s usually broken plaster keys which allow a ceilings plasterwork to sag down.
If possible, inspect a worrisome ceiling from above, as this is the best way to determine if a significant number of keys have broken off, allowing the plaster to sag. Usually you’ll access the top of a ceiling by lifting out loft insulation on the top floor or by removing floorboards on lower levels.
In the pic above you can clearly see the ceiling underneath is in good shape with most of the plaster keys still intact and nicely curled over the laths. I thought that wasn’t too shabby for a house built in 1722… (I know, actually pretty amazing huh?)
You’ll probably find some broken keys though; it’s fairly inevitable after all this time, but as long as the majority are still firm, the plasters structural integrity could still be good. If there’s a lot of debris covering up the keys, gently, and I mean really, really gently, clear it away using a paintbrush or a brush attachment on a shop vacuum cleaner (on a mild-power setting). On no account, scrape anything, ever. The keys are really quite fragile, even when in great shape. Work like an archaeologist who’s just discovered the find of a lifetime…
Hope that helps!
Cheers
Ian
I ma in Australia and have lathe plaster walls and ceilings in my attic from the 1850’s. Most in great condition except for one section going from the wall on an angle to the ceiling. i can get behind the boards to reglue but what would be a good produce to use that is available in Australia.
Thanks
Author
Hi Margaret,
Well, for a small area almost any water-based acrylic type adhesive will do. Look for one which is flexible and as ‘thin’ as possible. If it’s too thick you might have trouble applying it. If you’ve good access then you could thin a ‘tube’ style acrylic/ water based glue down even further (squirt it into a bowl and mix in a little more water) and brush it around the damaged areas. Don’t forget you’ll need to push up and support the sagging plaster from underneath. You can do this using a few screws through some big plastic washers etc. Unfortunately, I’m long way from you so I don’t know what’s in your stores specifically. Do you have a local store which has some older, knowledgeable staff you could ask for advice? Alternatively, read the back of the packaging and do some ‘test’ trial runs first on some scrap wood to see how each one dries and sets.
Let me know how you get on,
Stay well
Ian
Hi Ian,
Thanks so much for the great article. I have two holes in the ceiling of my 1960s condo unit. Both holes are about the size of a watermelon. The holes were caused by water damage to the plaster. Beneath the plaster is just concrete. I don’t see any type of lathe. There are only a few millimeters of space between the concrete and the plaster. Seems like everything I find online refers to using the lathe in the repair process. Any suggestions on what I can do? (Apologies if you’ve addressed this in a previous comment and thanks so much for taking the time to read this).
Author
Hi Sam, sorry for the delay, I’ve been abroad for a funeral.
I think you can safely ignore the lath and plaster advice as it looks like your place is a different type of construction. i.e. regular plaster on a hard substrate. You should just repair the damage with a backing coat plaster and a thin topcoat or two. However, I’m a little surprised that water damaged a plaster on a concrete substrate. Concrete is usually pretty unaffected by water in the short term. What country are you in and what style of house etc? Or pop a photograph or two into a comment or email me… and I’ll help if I can 🙂
Cheers
Ian
Hi Ian, on a similar subject I have removed Lath from some old lintels around 3 windows and have tried wire brushing off but can’t fully remove the Lath/mortar lines. Any suggestions as to how to remove the marks completely as I intend to leave the wooden lintels exposed?
Thanks
Tom
Author
Hi Tom,
You might struggle, the lime tends to really burn its way into the old wood. I’ve never tried to clean up beams to leave them natural as most of my clients end up painting them (either black or white bizarrely). The guys over at woodweb have an old thread about this.. hang on I’ll find it…. Here, http://www.woodweb.com/knowledge_base/Removing_Masonry_Lime_Stains_from_Wood.html Some things to try. Be good if you had a piece of lime stained wood not being used to try some of these out on though.
Let me know if you hit on a good solution (pun intended lol!).
Thanks for reaching out Tom!
Cheers
Ian
Thank you for the input and the plaster wisdom Ian. I appreciate your time and I will let you know how it works out.
Take care until then,
Ryan
Question if you have a moment,
I have recently removed all the old blown in insulation above my plaster and lathe ceiling. While removing the insulation I noticed that a lot of places have broken, or gone entirely, keys. For the most part the ceiling is not sagging and I have repaired some minor cracks with the screw and adhesive method.
Since I can clearly see the spots with missing keys from above, is there a way to use an adhesive from above and fill the spots to bond the plaster to the lathes?? I seems like I should be able to go down the spaces in the board and adhere the plaster to the wood from above with a construction adhesive or something similar. The ceiling is in good shape and is not sagging or otherwise cracking, yet, but seeing that the keys are failing in some places I was hoping to be proactive..somehow. I am in North Dakota so my time to re-insulate is running short. The negative temps are not to far into the future as we are dipping into the 30s at night already. Is this completely unrealistic? Please advise if you have any thoughts or ideas.
Thank you in advance.
Ryan
Author
Hi Ryan,
Yes, many folks have stabilised poor keys in this way. My only caveat is finding something which is sticky but also a little flexible too. The last thing you want is to soak the plaster with something which sets hard and rigid. A flexible adhesive should work well, especially if you carefully vacuum up the dust using a brush attachment and not too much power. Some people even lay strips of a fine mesh over the worst areas and then spread the adhesive through it if you like to create good areas. In the old days they would cover the whole area with mesh, screwing it into the sides of the joists and then add a sticky material over the whole area. I think this method fell out of favour in recent years though as it can add too much weight.
It sounds like you’re on top of the job so go ahead and tidy up the worst of it with something sticky before covering it up again.
Let me know how you get on.
Cheers
Ian
Hi, Some great advice there. We have gone with option 8; completely remove the old laths and plaster and fit new 12.5mm fireline plasterboard on metal studwork (MF6A). Now the laths have come down I see the void between the joists with an array pipework. There is a bedroom above and below. Would it be worth putting some kind of insulation between the joists to give better noise soundproofing? Or would this just be in the way should the floorboards be lifted in the future? If so what insulation is easiest to fit between 7″ high, 14″ wide joist cavity. The only problem, the team are due to return Sunday afternoon to fit the studwork.
Author
Hi Andy,
Depends on the ‘rules’ where you live really. In the UK, for example, it’s not common to insulate in between floors, but here in Norway, everything is insulated! You could cut rockwool or fiberglass to fit the odd spacing. You can buy 1200mm rolls and saw them into 14″ wide slices before unwrapping. Just be aware that regular insulation is not terribly good at soundproofing. Rockwool is a little better but to achieve any meaningful sound insulation is expensive. You need either density or a break in the physical structure (or both). For example hanging the studs from special foam insulated brackets works well, (isolates against transmition) as does double boarding (gives density).
Sorry it’s not simple. Have a chat with the lads on Sunday and see what they think…
Cheers
Ian
Hello,
Some interesting suggestions there. We have a 1870’s home and in some rooms the original lath and plaster ceiling remains, or did until last week. 2sqm of a 16sqm ceiling collapsed, for no understandable reason. There was wood chip ceiling paper, been up for years and hiding some small cracks, but certainly no sagging and the rest of the plaster remains firm to the ceiling. There is a bathroom above, but the lath and plaster is dry as a bone. There was someone moving in the room above, but not doing any erm, heavy exercises to cause stress. Anyway, a proper built old ceiling should stay up for 100’s of years, shouldn’t it. Have you any experience of plaster losing grip to the laths? We are struggling to find a reason why the ceiling collapsed and of course are now worried about other rooms.
Author
Hi Pike,
Interesting. Quite rare for a ceiling to actually collapse, so you’d be right in concluding that something must have happened to cause the plaster to lose grip. Well, to start with, let’s look at how the ceiling holds up under normal circumstances. Most folks think that the plaster sticks to the lath but that’s not strictly true as the lath dries out over time and shrinks (or swells if it gets wet with similar results). Plus there’s movement of the wooden parts of the ceiling to contend with. All this boils down to the ceiling actually hanging from the lath from the nibs (or curls, snots, keys etc.) like a suspended ceiling if you like!
OK, fast forward to your ceiling, the keys holding up the plaster have broken off. BUT, that might have happened ages ago, woodchip can be near miraculous in its holding power.
What is exactly above the failed area and ask yourself, has anything ever hit that floor hard, even once? No leaks in the past from what you say so you can rule that out. The other thing to look at is the condition of the joists (if you can). We had a damaged ceiling once caused by a couple of rotten joist ends in a wall under a leaking gutter. The soft joist ends compressed and pushed the ceiling down.
You are right in that (undisturbed) a lath and plaster ceiling will last generations. At least you should be able to effect an easy (ish) repair if the rest of the room is firm. I’d definitely be checking over any keys you can access easily (loft, under loose floorboards etc.) for peace of mind.
Sorry I don’t have a smoking gun for you, but don’t hesitate to get in touch if I can help.
Sorry also for the delay, working on a peach of a job right now away from home in an old fjord side cabin with a severe case of rot from some leaky old windows…
Cheers
Ian
Hi Ian,
We have just bought a Victorian terrace that retains a mixture of lovely original features and 1950s bastardisations. In one of the rooms is a Victoria lath and plaster ceiling with original ornate grape design. In the centre however, is a rectangular section in which the ceiling rose has been butchered. The areas outside this rectangle are quite beautiful and sound. The room’s only tiny window has been bricked up and cannot be restored, so we are wondering if it is possible to cut out the rectangular section and replace it with a skylight. It would look fantastic (we had a similar project with a pressed tin ceiling in a different house) but I am concerned that the plaster will separate from the lath when we cut into it and the whole thing will come down. What could we do to prevent the plaster coming off the lath in the rest of the ceiling? I thought about drywall screws first, scoring with a zip cutter to the lath next and then cutting the lath in a third step. Is that even possible? Many thanks, Carmen
Author
Hi Carmen,
It is possible to cut out a section exactly as you say. We use the Fein type multi saw with a mortar blade first, followed by a regular wood blade. The thing you’ve to watch is movement obviously. That means no big levering to get the laths off/nails out/timbers etc. The other tricky part is building any framing you need to get up to the actual roof and the finishing off. I.e. everything has to be done like you’re sitting on top of an unexploded bomb!
Once you’ve carefully cut out the hole you might then have good access to the top of the laths, (assuming the roof has a pitch), so you’ll be able to stabilise the plaster surrounding the hole somewhat using a glue/binding agent brushed onto the carefully cleaned ‘nibs’. This should soak into the soft plaster and help stick any loose bits back together and/or to the laths. You can as you mentioned use a few drywall screws but be careful, sometimes if there is a small gap somewhere, ‘pulling’ it up with a screw creates stress and can crack the plaster causing an upside down ‘elephants foot’.
All in all, perfectly possible but a real careful hand is needed!
Would love to see the pics as you do the work 🙂
Good luck and steady hands!
Ian
Hi,
This looks a great article. I’m so glad I’ve found you.
We have a problem with an outside overhang which is lathe and plaster in our 1890’s house in the UK. The wasps we get every year have eaten away some of the overhang and chunks are now falling down. Previous builder repairs on other smaller loose patches have not held and this hole is now pretty big, with more loose material around it. Can you advise anything that might patch it up to deal with a north facing overhang and the great British weather?
Thank you so much.
Harriet
Author
Hi Harriet,
Wow, you don’t often see lath and plaster outdoors. It must be quite a special house. I think first you need to gently remove any loose stuff surrounding the hole otherwise any new material will struggle right from the start. Be careful (and very gentle) though, if it’s fragile you could end up in the situation of not knowing where to stop! I’d have thought fingers only would be fine, just piggle (technical term!) away at the loose edges until you’re back to reasonably firm plaster.
Then it depends on what is in the hole. If there are visible lath and they are in good condition, make sure the gaps are clear and then I’d damp down the dust (especially the edges of the old plaster) and fill it with lime based mortar to match the existing. It will need at least 2 or three coats spaced over a few days, with horse hair in all but the last coat. Finish off the last coat to match the surrounding plaster (a finer finish coat or is it just ‘rubbed’ up mortar?).
If there is no visible support for new plaster, i.e. it’s just a big hole. Either use new lath or a non-rusting wire mesh to fill the hole. I wouldn’t nail anything for fear of disturbing more plaster. Gently use small stainless screws instead (with washers if using mesh).
Hope that helps and apologies for not being more specific, difficult without seeing the hole!
Have a great weekend and thanks for the kind comments!
Let me know if I can help.
Ian
Some Lime Related Resources for you…
http://www.periodproperty.co.uk/shop/acatalog/plastering_with_lime.html. Find a great guide to using traditional materials here.
http://www.buildingconservation.com/articles/plaster/lime-plaster.htm. Popular misconceptions about traditional lime plasters are debunked here.
http://www.buildingconservation.com/articles/limehair/limehair.htm. Great article about the use of hair in lime plasters for reinforcement
http://www.buildingconservation.com/articles/internallimeplast/internallimeplast.htm. Good descriptive article on how to use lime plaster.
http://www.mikewye.co.uk/guidesheets/plastering-onto-lath/. Good video showing how to plaster onto lath (and lots of other lime-based videos too).
http://www.limestuff.co.uk/pages/user-guides/how-to-lime-plaster-onto-laths.html. Wiltshire based educator and supplier of lime products.
http://www.oldhousestore.co.uk/. Lime specialist site with some great resources about lime plus of course supplies.
http://www.lincolnshirelime.co.uk/. Lincolnshire based supplier of lime products.
http://www.bleaklow.co.uk/. Derbyshire based supplier of lime products.
http://www.ecolime.co.uk/. Yorkshire-based supplier of lime products.
http://www.womersleys.co.uk/. Yorkshire based educator and supplier of lime products.
http://www.mikewye.co.uk/. Devon based educator and supplier of lime products.
Hello, Ian, this is a great resource for old home owners, thank you. I am in the midst of repairing my 1915 Salt Lake City bungalow with plaster/lath. The walls are in decent shape, with a few very repairable cracks, but whoever did the lining paper previously did not do a great job. It’s actually bubbling in the corners. And there seems to be a light skin coat over it. Should I attempt to remove the old lining paper before repainting? If so, what is the best method? And should I reline it before repainting? Thanks!
Author
Hiya,
It does depend on what’s caused the paper to bubble really. If it’s a more serious underlying problem such as damp or moisture evaporating and leaving soluble salts behind then that needs addressing first.
The ‘skin coat’ worries me as I’m not quite sure what you mean. Hopefully it’s not the aforementioned soluble salts.
If all is well then by all means re-stick any loose paper back down. Bubbles can be cut and peeled open in a star shape to enable glue to go behind. use a fine filler over any repairs to fill any imperfections followed by a careful light sanding (not much if you are good with the filler).
Removing the whole paper might cause more damage than it saves. Good lining paper really does hold everything tight and together.
Let me know how you get on
Many thanks for the kind comments!
Happy Easter too.
Ian
I have done five coats of lime washed over these layers. Applied with a farm spray unit.
Hi Ian
I wonder if you still look at this thread?
Well I have a problem with ghosting plaster joint lines (white) through my limewash paint, made myself. I did Bondcrete 50/50 with water for first coat and 50/50 with lime wash for second coat.
Can you advise?
Author
Hi Jilliana,
Thanks for getting in touch and sorry to hear you’re having a problem! Hmm, ghosting means a little moisture is affecting the surface somewhere. This can be condensation, or it can be moisture penetrating from outside, but most common is cold bridging. By this I mean that parts of the wall are colder than others i.e. you can often see the studs or ceiling joists through the plaster/drywall etc.
Insulation in between timber woks fine but it doesn’t stop cold seeping through the timber itself.
Where is your wall? Is it inside, outside etc. What is the wall built from etc. And what does the ghosting look like, what can you see? Any chance of a picture?
Don’t hesitate to get back in touch with more details and I might be able to narrow it down!
Stay well
Ian
Number 11 made me choke on my coffee! I’m too much of an addict to sell so…
I am in the process of trying the glue method using plaster magic. My question is what’s the best way to deal with a crack ~1/2″? It’s a broken key and essentially the plaster between the lathes was loose, under the lathes is sturdy. It seems too small to plaster since I don’t think I can get a good key as I did where multiple lathes were exposed, but also too small to use joint compound on as I did on hairline cracks and where just the paint or old repairs were falling away. Thoughts? I have access to the ceiling from the attic and it’s a 1930s US house if that helps (lime plaster, no horse hair as near as I can tell).
Author
Hi,
Yes, new houses just don’t cut it do they? Unfortunately I don’t have direct experience of the materials you have in the US (I’m British) but is there a lightweight plaster? The sort they’d use on a metal lathing/mesh background? Hang on a minute….
…. hmm, wow, that was a shock! I just had a look at the Home Depot and the Lowe’s site (the two I hear all about ‘in the movies’ lol!) and you’re right (obviously) it looks like you guys don’t have the range of plasters we have. We do a lot of plastering directly on masonry you see (or used to, before we started sticking drywall to walls with bonding compound).
Right then, well, it is possible to cut a tiny strip of drywall from the bound paper edge, but that assumes the crack is straight enough… Otherwise the joint compound will do it, but it will take a long time because of the multiple layers and waiting for it to dry and shrink etc. You could try using drywall tape or mesh (fibatape?) to ‘bulk’ out the compound, i.e. cut thin strips or the mesh will just roll into tubes etc. Also, you might need a compound that sets via chemical action rather than air (thick coats of air dry stuff never sets as it thinks it’s still in the tub!). The downside is the fast sets might not be easy to sand down (maybe just use it for the bottom layers.
What about regular filler, what the decorators use? We use a lot of powder based fillers here which sand well, sure you’d still need multiple coats and you’d need to wait for it to dry and shrink etc… Cool, just learned you call filler spackling, interesting as that’s what the Norwegians (my current home) call it. Must be a word borrowed from you guys.
That’s all I got! Let me know your thoughts.
Cheers
Ian
Wow thanks for the reply on such an old post. 🙂
Let me clarify the ceiling description. Wooden lathe ~2″ wide, lime plaster from the 1930s. The crack is in the 1/2″ between the lathe strips. Since I’m doubtful I can get it to get it to key I’ll be relying on whatever I put in to adhere to the plaster nearby.
The painter I am thinking of using said to use FixAll patching compound, but he’s not familiar with plaster/lathe. A drywall strip crumbled because it was too thin. Thinking of using tape/compound unless you think I can get plaster to stick.
Not to sound like a commercial but I bought Big Wally’s Plaster Magic repair plaster when I picked up the gluing kit from a local ACE (like HomeDepot but staffed by people with manners). It was advertised as setting up more slowly. To a novice like me that sounded perfect, I needed that extra setting time. It’s mostly Calcium/Magnesium materials with sillica, perlite, and gypsum.
Author
No worries, it’s an old post, but it’s my post, so of course my tame robot keeps an eye on it for me!
I’d certainly avoid any plaster (lime and sand mix) as shrinkage will cause loss of adhesion. Re the drywall strip, (or layers of tape, mesh etc.) think of them more as fillers or bulking agents within the filler or compound you use to avoid it being too thick etc.
Most painters filler is designed for this sort of thing and have a good grab as well as good flexibility. Don’t tell the painter, but they often have to work miracles, dealing with a lot of erm, how can I put it politely; shortcomings say, from the other trades and often need to make good in difficult situations. The filler reflects this. Too many tradesmen leave behind bad workmanship assuming the painter will ‘get over it’.
Alternatively, as you know, drywall compound is miraculous stuff applied in thin layers over a few days.
Let me know how you get on…
Ian
I am in the process of a big project in my attic and have already removed all the insulation, exposing the lathe and the key from the plaster below.
My ceiling isn’t in bad shape (we have fixed some cracks but it isn’t falling down or in disrepair). Since I have this once in a lifetime opportunity to strengthen the ceiling before I put down insulation and attach the subfloor above I am considering trying to protect the ceiling long term by spraying a plaster bonding agent and then applying a fiberglass mesh before spreading gypsum compound or maybe elastomeric paint; essentially creating a sandwich around the lathe.
Any experience with this kind of fix? Recommendations for the right product to spread?
Author
Hi Jonah,
The method you describe is a common one (well except the elastomeric paint, I’d not heard that one in the UK). The problem from my point of view is that considering where the nibs typically break away (in the gap between the lath) adding stuff from above might not help re-attach the nib or replace the strength lost. I think that’s why there has been a drift away from these methods in favour of suspension systems working from underneath. Typically using stainless steel washers and either screws or wires up through the lath and plaster and into or on the side of the joists.
However, if your ceiling is like you say, sound with few if any broken nibs this is overkill. I can see the potential benefit of adding a bonding agent if it is flexible and able to soak in far enough to fill any small cracks forming at the base of the nibs but who really knows? Maybe the ‘glue’ will add strength but then again maybe it will make the ceiling more rigid which is not necessarily a good thing.
Problem is that if the nibs are OK but you start ‘messing’ with them, the end result might not add any benefit as they are soooo easily damaged. Just touching a nib may break it off, whereas if left alone it’d probably have happily sat there for decades more.
Sorry, just being the devil’s advocate now, not very helpful!! In conclusion, if you can find a suitable, flexible, penetrative agent able to make the plaster ‘sticky’ again around the lath I’d consider that a fair idea but I’d probably resist adding more weight via mesh and plaster on top of the nibs through fear of making matters worse…
Well, that’s given you something to think about! Sorry I’m not able recommend a product where you are, but like I said above make sure any bonding agent you use has those attributes. Do you have access to a decent store nearby with experienced staff?
Best regards and don’t hesitate to let me know how you get on.
Ian
Author
p.s. Jonah, one other thing, make sure the insulation you choose is a a breathable one (sheeps wool is a favorite here). It’s just that you don’t want anything above the ceiling which slows down the passage of moisture through the ceiling which could in turn damage the nibs over time.
Thanks for the reply. I should mention that although the ceiling seems well attached, my concern is that the key doesn’t seem to extend past the lathe in many places; this is why I am even thinking about it.
As for local stores, plaster is a lost art in the US and while our big box stores and local hardware both carry plaster, they don’t have any knowledgable staff.
Perhaps you could explain the what you think “glue size retardant” refers to in the following I found while researching this.
Also, would you suggest soaking the lathe with water in addition to spraying a bonding agent? Before or after?
“After dampening the old lath and coating the damaged area with a bonding agent, a fairly liquid plaster mix (with a glue size retardant added) is applied to the backs of the lath, and worked into the voids between the faces of the lath and the back of the plaster. While this first layer is still damp, plaster-soaked strips of jute scrim are laid across the backs of the lath and pressed firmly into the first layer as reinforcement. The original lath must be secure, otherwise the weight of the patching plaster may loosen it.
Author
Pretty typical situation in the UK too.
I’d be wary of wetting the bone dry lath too much, lest they swell and further damage the nibs. It seems like you do need to add in some extra mass on top to provide a new key. If the nibs are broken away there is virtually nothing holding the plaster up as the lath itself shrinks away during the first few years leaving the nibs alone to carry the weight of the plaster underneath. Your goal now is to stick the new plaster to the plaster exposed in between the laths after very carefully removing the broken nibs.
I wouldn’t damp down the lath as the bonding agent (watery glue essentially) is usually wet enough. You can use regular drywall scrim to reinforce the new plaster which should be as fine as available. Plaster of Paris or casting plaster typically.
Cheers
Ian
Hi! I’m helping out a friend with some repair work on her old house. There’s a small area of ceiling that needs help. I scraped everything that was loose. The exposed lathe cement (hopefully the right term) is soft enough for me to dig my nail in it. She doesn’t want to bring the whole mess down. Should I simply put up a piece of sheetrock over it or is there something that will “seal” the soft stuff? The area in question is a tiny hallway about 5′ by 3.5′. Thank you for any advice!
Author
Hi Heather, by lath cement do you mean the lath or the plaster covering the lath? If you have exposed the wooden strips or lath then by all means stick or screw up a piece or drywall. But if it’s the plaster you’re looking at and it’s not that well adhered to the wooden lath behind you might need to be careful. However, as it’s so small an area I think you’ll be fine to screw up a piece of drywall over the whole thing and finish it off. Just make sure you find the joists behind the plaster and use a drywall screw long enough to get into them about an inch or so.
Good luck and feel free to let me know if I can help.
Cheers
Ian
also can i use mullti finish modern bonding to patch in the cieling
Author
No Andrew, it’s too stiff and will probably crack as it dries hard… Some folks stick self adhesive tape over the cracks and then skim the whole ceiling, but your mileage may vary with this method as it depends on how secure the plaster is and how stable the ceiling timbers are. I wouldn’t do it these days….
my cielings sagging all over the place how long does the glue take to stick and how long will it last
Author
Done properly the glue method can last for decades, but it’s a delicate job. It requires careful drilling and in the right places plus careful application of just enough glue (too much will belly down the loose plaster even more). Most folks apply a little glue into the holes and then prop up the sagging plaster using plywood and light props (not too much though). Most glues set within 24 hours. After the glue has set, scrape out the cracks to leave a shallow ‘V’ and fill using a sandable decorators filler (powdered and water is better than premixed stuff). Sand the filler after it’s set. A lot of folks then go for a lining paper before painting….
Hi, we have a corner of bumpy/bubbling plaster from past water damage in our bedroom. We fixed the roof, so no more leaking. I’d like to get a contracter here to fix that area to make it smooth again but was curious if we could fix that section only. Any suggestions, and cost estimates are appreciated. I don’t want to get ripped off. Thanks!
Author
Hi Kristen,
Normally it is possible to repair the damaged area….. however; (here it comes!) it does depend on the condition of the rest of the ceiling. You can fast approach the cost of a whole new drywall ceiling when trying to repair damaged lath and plaster. Also, many contractors will not attempt a repair as it’s difficult to do well and hide the joint (between the new and old plaster) and so will recommend replacing the ceiling with drywall.
Estimates I can’t give as the extent of the work is not clear and contractors vary widely (and I’ve been shot down on flames before lol!). It’s best to talk to a couple of contractors if price is a particular issue and them you can be sure you’re paying a fair price etc.
Hope you find a decent guy!
Cheers
Ian
lol lol lol! 😀 buy a new house that’s the one. I knew I would find an unconsidered solution if I did a google search. Thanks gonna start the process today.
Author
Some folks are just not cut out to be the proud owners of a
money pit, sorry, I mean a fine period house…. *smiling*Good luck with the search!
Ian
We have a ceiling where some of the plaster has failed (photo available on request). Interestingly after the hole there is a crack which runs parallel(under?) a joist. I have lime plastered walls , but never ceilings before. T’other half wants to get it plasterboarded as she thinks the lime plaster will fall on her head. There is a sound wooden lathe backing behind. Any thoughts gratefully appreciated.
All the best,
Neil
Author
Curious Nick that the crack is directly under a joist isn’t it? Makes you think that the joist has flexed downwards and broken off the plaster keys between the laths. Has anything changed recently? Other damage/other repairs/new furniture/etc/etc? Just asking because it’s surprising how many times something new is introduced and then later on something changes as a (seemingly unrelated) result.
Ok, with out seeing it (I can look at the photo if you think it is clear enough to show anything) and loosing that ‘gut’ instinct (it’s real, believe me!) I’d go back to the beginning. Check out the ‘how to tell if your lath and plaster ceiling needs to come down’ page and give the rest of the ceiling a good inspection.
Then your options vary depending on how secure the rest of the plaster is. Assuming that it is, repairing small sections isn’t too bad. If you’ve had a go at lime plastering already, you’ll love doing a ceiling! It’s the same as doing a wall only you get to ‘wear’ a little more mortar! Plenty of hair in the first coat and make sure about half the stuff goes through the gaps to form good keys and don’t mess about with the first coat too much, again to preserve those valuable keys.
I am curious about the damage if it’s super localised though. Could anything have affected the joist? No big bumps from above etc.?
Feel free to ping me any photo’s (to ian@handycrowd.com) and we’ll chat again…
Cheers
Ian
Author
Ian,
I think the failed plaster has been ‘held in’ by the wall paper for some time.
We have noticed a bow for the last couple of years – just ignored it.
I have been doing lime wall plastering in the same room and perhaps the knocking has caused it to give up the ghost?
T’other half can’t be convinced – she is worried about my handy work falling on her head ! 🙂
So plasterboard it must be – says he with a tear.
All the best,
Neil
Author
Yes, does look bad doesn’t it! Will you be taking it down or battening and boarding it? Just thinking I could do with some fresh photos of a job in action so to speak!
Thanks for getting back to me, feel free to send me any pics you take of the job, I’d appreciate it for sure and I can send you a copy of the lath and plaster ceilings book as a tiny compensation lol! (plus later this year I could send you a copy of a much bigger book due to be published (How to be Handy)……)
Best regards
Ian
hi ian
i am decorating an old pub with lathe and plaster walls can you suggest what i could seal walls with as powdery before i line them also a suitable adhesive thank you steve
Author
Hi Steve, you need what they call a “primer sealer” to stabilise all that old dust.
BUT, be careful if the ‘dust’ is white and salty as this means there is damp evaporating from the wall, especially if it’s around the 1m or 3 foot high mark. As you know sealing in damp is asking for trouble. But realistically, I expect that no one wants to spend more than they have to on an old pub, so you’ll probably have no choice but to carry on.
Invest in a good brand of primer sealer and then use your regular paper paste as the wall will not soak it up because of the sealer.
Thanks for asking, let me know how you get on or post some pics!
Cheers
Ian
I am working on a old house ,the plaster is about 1&1/4 inch thick, no lathes, no 2x4s just the brick exterior walls. How do I repair the plaster?
Author
I’d need more info about the walls first. For example, is it an old house where the brickwork started to deteriorate and the (then) owner decided to cover it up with render? Also, is the render hard (cement) or softer (lime mortar)?
Let me know and I’ll advise you what to do.
Cheers
Ian
Hello Ian,
Thanks for the great no-nonsense advice on your page. I live in Prague, Czech Republic, and this year I bought a small flat in a building from 1938. A lot of my reasons for choosing it were the old, and absolutely perfectly undamaged 3 metre high ceilings, which had clearly not had any cosmetic touch up for around the last 20 years or so.
The sad story began in July, when flooding was caused by careless builders working upstairs. Since then, it has been wet to various degrees 6 times. That number is unfortunately not a typing error.
Now, almost half of my total ceiling area is ruined.
Might I ask you for your opinion on the repair?
There are very very secure laths above the plasterwork. They are 2 x 1 inch in size and as solid as a rock.
One fortunate thing is, thanks to the hot weather, that the ceilings dried within 3 days after each flooding. I don’t expect to discover any rotting issues with the laths, would you agree?
Next, I expect to try to repair it myself, as hiring a plasterer could cause more damage than good.
In my time, I have worked as a laborer for both internal and external plasterers, doing full plaster boarding work and quite small sections of skim coating. I am well able to cement plaster and float down a cement finish wall.
Do you think I stand a chance of being able to re plaster half of the ceiling area in each of my rooms?
Time isn’t a problem, I am prepared to spend weekends at it, and to work in sections of course. If you think I’m not dreaming too much, then what type of lime rendering would you recommend to me? And roughly what to budget for to re plaster a total of 30 square meters? (In GBP or euro, if it were a UK project)
Thanks very much for any help,
Kevin.
Author
Hi Kevin,
Sorry to hear of your ceiling troubles. The trouble with recommending a product is that you might not be able to find it where you live. Normally you will be able to find a local product that is suitable for your house though. I would say to go to the best builders merchant in your town (the same one the professionals use preferably) and tell then what you are repairing and get their advice on what to use.
It sounds like you will be able to do the repairs yourself and the budget will be little if it is only a little mortar you need to purchase. I can’t tell you exactly as I don’t know how expensive building materials are where you live.
Take your time removing the damaged areas and make sure you go back to really firm areas before re-plastering. Damp the edges of the old plaster before plastering up to them with new stuff and you can use a damp sponge to wipe away new plaster that strays onto the old stuff.
Good luck and thanks for taking the time to ask a question Kevin.
Ian
These are some really great suggestions! Thank you for making your experience accessible to us DIY folks 🙂 I am struggling with what to do for my walls in my 100 yr old home (a baby by most standards, I know).
Most of the plaster seems solid, but within the last year or so, I have noticed there are some sizeable “soft spots” where the surface plaster seems to be delaminating in places. Some make sense (around the hand rail mounts where my kids have run up and down the stairs grabbing and yanking at the rail as they go.. to my dismay for the last 7 years) but there are other random places that almost seem like a “bubble” has formed between the layers where there is no load bearing and no heavy traffic. (a couple the size of small dinner plates in looseness).
I am not averse to scraping out the loose parts and refinishing, but I am so confused what to use and what has happened. What is the best product to ensure adhesion of finish plaster and what kind to use? So many arguments for and against PVA or other bonding agents.. I am overwhelmed.
There is hardly any information that I can find for this condition vs the cracks that they are repairing with Wally’s where the plaster itself has pulled away from the lathe and is flat and smooth and appears to be an entirely different finish than mine. Durabond seems to be the product of choice in the US, but given all of the products and their differences listed on the MULTITUDE of plaster websites in the UK, I am beginning to believe no one in the States has a clue how to take care of these homes.
Most of my plaster seems to be solid behind these loose spots. (a couple of spots have already lost the loose plaster and there is hard, white, smooth but sandy plaster underneath with no “spring”. Sadly they do not have the beautiful smooth final finish, but that annoying texture like bits of rock mixed in here and there. I have not scraped any off to see if that is in the paint or the plaster as I am afraid it might be the plaster. If it is in the paint, I can just scrape them off and “do over”.. but what if it is part of the plaster itself??
I love my house but she is starting to come apart on me and I want to save her!
Thank you for any advise you can give, I just want to make my money and effort count where I can.
Author
Hi Stephanie,
I understand that it is daunting to start ‘digging’ into the walls! We don’t mind I guess because we know that we can fix it up regardless whether it’s a little hole or a whole wall lol!
There are various reasons why things fail and it really doesn’t matter much either because it’s the end result you need to fix. It’s just going to be a case of gently exploring the soft spots with an old knife or a small trowel to find out what is going on. It might just be the thin skimming layer, do you say ‘veneer’? that has crumbled into dust and needs filling/spackling etc.
Don’t be frightened to have a look, it’s the only way to find out what new materials you need to buy and how much! Lots of older plaster is quite fragile since it’s not cement based but lime which can be damaged over time, especially vibration or impacts.
Be brave and have a little look and let me know what you find!
Best regards
Ian
Hi Ian interesting article…. I have an old (1600s) house in Gloucestershire and I have made use of a few of the tecniques listed above in various rooms. I’ve just finished replacing part of the ceiling in what will be the bathroom where an area of lath and plaster was coming down. I used new lath and hemp / lime plaster as a scratch coat over this area. I also screwed plastic washers into the joists along the whole length of the joists (even the areas of the ceiling which were OK) and then scored the old ceiling with a stanley knife and skimmed the whole lot with lime finish coat plaster with some fibre added to cover the plaster washers and give a uniform appearance.
I can’t manage polished smooth plaster so I then floated it up with a sponge float. Pretty happy. Builders quote – £3500. My costs – £75 + time.
Author
Sounds like an interesting house Toby, seriously old! Nice to get a comment from someone not asking about plasterboards too. Sounds like you managed a sympathetic repair on your old lath and plaster, I wish more folks would give some of these old materials a go.
I actually think that lime finish plaster is more forgiving that the modern stuff which you have to get just right before you can trowel it up and with a bit of breeze can set in a jiffy on occasion. Have you tried running over the plaster after you’ve floated up withe the sponge? Just thinking that the sponge will level out some of the highs and low spots and the metal trowel might just ‘seal’ the texture front the sponge. Having said that, if you’re getting a finish you’re happy with what more is there to do 🙂
Oh, What type of plastic washers did you use, one designed for holding plaster or something you found locally? Be nice to have a link for those too.
Thanks for taking the time to leave a comment Toby, it’s always nice to hear about real world projects that are successful.
Stay well
Ian
p.s. If you have any photos, I’d be delighted to write them into an article here as an example of what’s possible.
Thanks Ian
Our house is listed, so I was told I can do “like for like” repairs only without going through the listed building consent process. Whilst I wish the application process was easier in some ways the house being listed has been a blessing as it has made me take the time to learn about my house before just ripping things out and replacing.
I got the washers and the hemp lime from Ty Mawr http://www.lime.org.uk I think the washers are intended for fixing wood wool boards, which have a bit of flex in them so the can be pulled flush with the rest of the surface. They are maybe 2mm thick but are dimpled and holed to carry plaster. It meant I had to apply a thick skim coat of about 5mm to cover it all up, which meant I had to put quite a bit of fibre in the skim coat – I used very fine poly prop fibres intended for use in concrete reinforcement….. Not entirely in keeping with old buildings, but a small concession – horse hair would have shown through I think.
I haven’t tried lime / aggregate backing coats onto lath but was really happy with how the lime hemp went up, very sticky and light. When it sets (which is about 3 weeks) it is rock hard too. I’ll post some pics after Christmas when it is all finished!
Author
Sounds like quite an innovative mixture of new and old technology Toby! Totally agree about learning a little about the house first, knowing how the house goes together and using matching materials will mean fewer problems in decades to come. I feel quite embarrassed at some of the work I did decades ago (along with everyone else at that time), using cement for re-pointing etc on many a terraced house. But the knowledge ‘on the street’ so to speak, just wasn’t there in those days (outside of the heritage world), plus folks were always looking for the cheapest quote.
Even now, the world of heritage repairs (like wine and art) tries to retain this mystical air and aloofness that really needs to be knocked down in order for the techniques to become ‘demystified’ and widespread. So many bricklayers I know won’t touch real lime mortar because they are terrified of it’s ‘complexity’. As you and I know, using lime utilizes so many of the same techniques and skills many of us already have. A little new knowledge about the material is all that’s needed (just like employing many of the new things that come to market).
At least now you know your ceiling is quite secure and any minor cracking that occurs as a result of the old girl ‘wiggling her bottom’, is just cosmetic and nothing to worry about.
Would really appreciate looking at the pics Toby, thanks again for talking through what you did, appreciate it.
Merry Christmas!
Ian
Ian,
I need to get a ceiling repaired in a 1930s house. The ceiling is upstairs with access to the attic above. As well as the usual cornicing around the ceiling perimeter there is also decorative plaster “mouldings” on the ceiling itself. Several cracks on the ceiling and from above I can see that the plaster nibs have come away from the lathing in places. I have read that it is possible to push the ceiling back up from below, support it and pour finishing plaster over the laths from above. Do you think this is a viable solution?
Author
Hi Michael,
I wouldn’t recommend using finish plaster, but it was a common solution back in the day, even if not very successful! The problem is that it’s difficult to get the surface clean enough for the new plaster to stick well enough. Plus, although plaster is sticky, it’s not technically very sticky, I mean sticky like a proper adhesive. Sure, plaster sticks to the wall, but then it has huge area on its side, use plaster to try and hold something when it’s only 1/4 wide is asking a lot.
Your options are to use a wire mesh and resin system, where the resin will grab a hold of the plasterwork below and is reinforced by a layer of thin wire mesh fixed to the side of the joists.
The alternative that is gaining a lot of favour nowadays is to inject an adhesive into small holes and gently push the plasterwork back up into place and support it on blanket covered timbers and quick grip props. Old house online has a great description here http://www.oldhouseonline.com/how-to-fix-plaster-ceilings/ which will give you an idea of whats involved. This can be done from above through the lath (more tricky to stop the drill before it goes through the plaster!) or from underneath where you drill through the plaster and stop at the underside of the lath. Squirt in your adhesive, gently push up into place and support till dry. It’s a fair repair and although on a typical ceiling you’re looking at many hundreds of holes, they only take a few seconds each. This would be my best bet and certainly it’s better than using plaster.
Let me know how you get on or even ping me some photos and we can pop them on here to help someone else.
Thanks and good luck Michael!
Stay well
Ian
Just bought a lower conversion dated 1860. Quite severe cracks in ceiling and cornice work in front lounge. This information looks invaluable. Looking forward to using this site for the many jobs that will arise. Several cracks elsewhere but the Home Report provided (Scottish requirement) states this is due to “settlement” and not a major issue.
Author
Hey Billy,
Sounds like a lot of character! Looks like you need to get up there and see how solid it all feels. Hopefully everything is still firm and the cracks are like you say, just a result of the old girl moving about over the years. Then its a case of filling and a few coats of paint. Time will then tell you what you need to do come decorating time again.
Good luck with the new home and thanks for stopping by 🙂
Cheers
Ian
Hi – I’ve read your article with great interest..
We have a Victorian country / farm labourers house made from Clay Bat and has Lath and Plaster ceiling..
All ceilings have been overboarded and re-skimmed with great success – since the laths were secure to joists and plaster heavily cracked.
All the ceilings in the house are very low 7′ 6″.
Problem was the bedroom ceiling which I have been avoiding – laths separated from joists and sagging up to 30mm partially …… when I stripped the walls of paper use steamer the ceiling got worse and my idea to overbooard was looking very doubtful.
I read your article about battening to hold laths up to joists ….. great idea ….. but needed something thin dceiling due to low height …. also batten shims seemed to make the job difficult.
What we did we used galvanised steel “bulders band”. This allowed us to screw up and all laths were secureed back to joist … really easy …. one man job. Ceiling now secure and solid. Then we overboard with 9mm thick plasterboard. We will skim it tomorrow.
At the moment very happy – builders band cheap at £7.00 per 10m roll – so total cost £28 to scure laths.
I am sure it will skim up ok. So thanks to your article we came up with this further idea.
Cheers – Tom
Author
And me too Tom! Great and innovative idea to use the builders band, I’m interested in how many times you hit the band whilst screwing up the plasterboards though?!
Yes, I agree that it will do the job admirably, it’s nice when you read something and it sends you off down another road to the same destination isn’t it?
Good luck with the skimming tomorrow, it’s been a while since I’ve seen proper plastering, it’s all tape and fill over here.
Glad to have helped, albeit very indirectly!
Stay well
Ian
Hi Ian
This is a very good article on plaster repairs.
I found it whilst trying to find out how old my plaster ceiling is.
Its lath and plaster, but does that necessarily mean it’s lime plaster?
The surface plaster is white and the plaster underneath is very dark grey.
The building is grade II listed, built late 1700’s. Its a townhouse on a terrace; the house has ben converted into flats many years ago. So it may have been replastered when it was converted.
Norway is a cool place. We have been skiing in Geilo several times over the years. Very expensive for food and eating out though!
How much ?? 🙂
Author
Hi Bee,
Yup, Norway certainly is expensive, especially in the ski resorts!
Hmm, white and grey plaster is ringing a bell somewhere deep in my mind, just can’t quite remember where I’ve seen it! Certainly there are regional differences between lime plasters used that lead to colour and texture differences. I’ve also seen good existing laths re-plastered with modern or lightweight plasters several times hence it being in my top ten list. The colours you describe do sound like it’s been re-plastered sometime. If you have access to the plaster above (in the loft for example) you might be able to see more, if there is hair in the backing coat for example. Hair should mean that its lime based.
Usually you can tell if it is lime based by how it is ‘wearing’, if there are random cracks on the surface it’s unlikely to be a modern plaster which tends to crack in straighter lines, but even that is not terribly conclusive.
If you are searching, does the ceiling have a problem or are you just curious?
Thanks for the comment!
Cheers
Ian