Thinking About How to Repair or Remove your Lath and Plaster Ceiling?

Step by step guide to making dust…..sorry, I mean fixing up your lath and plaster ceiling!

Traditional lath and plaster ceilings and walls, (or lathe and plaster depending on your spelling!), really add to the charm and feel of living in a period house. Unfortunately, lath & plaster is prone to cracking, sagging or even partially falling down. The good news is that it’s often possible to repair lath & plaster ceilings (and walls) and make them last a while longer, (it depends on what look you’re aiming for and of course your budget).

repairing a lath and plaster ceiling with large section missing

The plaster has started to fall away in this ceiling, exposing the lath, but only after 150 years!

However, since you are here, you might have a sagging ceiling or one that is badly cracked and falling off the laths. Arguably you could be justified in removing the plaster and/or the laths altogether and starting over. Or you might want plasterboard (sheet-rock in the USA) right from the outset, recessed down-lights in the ceiling being the usual culprit!

OK, lets take a look at your plasterwork and go through your options. Its a long page but there’s a lot to explain!

Caveats first though OK. This ‘how to’ explains how to carry out repairs and/or to take down a lath and plaster ceiling that you might want (and have permission) to remove. Plaster ceilings in some listed houses may need to be retained and repaired rather than removed (check first!). If this page tempts you into tackling this job yourself, please jump down and read my safety info first!

Also, I have linked to various external info and suppliers where it’s useful. Places like English Heritage, because they have good info about looking after old houses.

OK, enough blurb, lets get started……

Evaluating whether to remove your lath and plaster ceilings

Stand underneath one corner of your ceiling on a suitable ladder and with your head almost touching the ceiling look across the surface, do a 90 degree sweep looking for any unevenness, sagging sections, cracks etc. Try again from the opposing corners. Your ceiling may look flat from the floor, but once you get up there and have a closer look, you will get a much better idea of its condition.

Lath and plaster in 'textbook' condition

A sagging ceiling does not necessarily mean that the plasterwork has broken away from the lath though. Old houses settle and the ceilings go along for the ride. So, if your ceiling is sagging or sloping, it may still be OK.

If there are areas where you suspect that the plaster has separated from the lath gently push upwards with the palm of your hands. A little give is normal but if you feel the plaster move up and down, this means that it is not attached to the laths. Dust and debris may fall from cracks as you do this.

NOTE: Don’t go crazy here, if you push and shove a really bad ceiling hard a few times, you might end up ‘wearing’ it! Go gently :-?

lath and plaster and how it fails

Lath and plaster and how it usually fails

Sometimes the lime mortar or plasterwork separates from the laths and drops down. Effectively this means that the plasterwork is hanging underneath the supporting laths and joists, virtually unsupported.  Sometimes it is only the horse hair strands in the mortar that is holding up the plasterwork!

If left in this perilous state, chunks of plasterwork will eventually start to crack and even drop away, either in small pieces or in large sheets if there is a water leak or even someone jumping on the floor above etc.

Because repairing a lath and plaster ceiling like this can be expensive, you might make the decision to remove it completely and replace it with plasterboard.

However, we are getting ahead of ourselves, as there may be alternatives to completely removing all the plaster and laths in your ceilings.

Alternatives to removing a bad lath and plaster ceiling….

Over-boarding with plasterboard

  • 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, hence being first in this list! (Or for overboarding “plus”…….)
  • Screw 25mm x 50mm battens underneath all of the existing joists. This ‘sandwiches’ and supports the  old plasterwork. The battens can also be packed level/flat using thin plastic or timber ‘shims’ as they are screwed tight. Plasterboards are then fitted as normal, (sometimes incorporating insulation and a vapour barrier).

Repairing limited damage or cracks in lath and plaster (ceilings and walls)

  • If your ceiling has some cracking but feels pretty secure otherwise, then the cracks can be repaired. Scrape or brush out loose material from the cracks and fill using decorators filler. Fine cracks could be filled with a flexible decorators caulk and smoothed over with a filling knife.
  • 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’!?!).
  • 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 can be re-plastered using modern lightweight backing plasters and finish plaster. 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.

Re-plastering with traditional lime based mortar and plasters

  • A rare alternative to complete removal, is the removal of the sagging and broken plasterwork and re-plastering the original laths (assuming they are OK) with a suitable haired lime mortar and lime finish plaster. You will 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. A specialist job in effect.

Fully repairing a ‘protected’ lath and plaster ceiling

  • This goes beyond what I intended to write about here, but of course given enough time and money even the worst ceilings can be rescued, as you would to satisfy the authorities if your ceilings were historically valuable.
  • Briefly, the plasterwork is gently supported from underneath and working from the top all broken keys, dust and often centuries of debris are carefully removed.
  • Repairs can then be carried out using stabilizing chemicals, wire mesh and adhesives or plasters, with the aim of reattaching the plasterwork below.
  • Complicated, expensive, not your average DIY project and arguably beyond even the average builder.

And when all else fails……………

How to completely remove a lath and plaster ceiling….

Tools you will need

Fortunately you don’t need many and you may already have them in your tool kit.

  • Working platform, sturdy step ladders or builders trestles etc
  • Claw hammer or other lightish hammer.
  • Gauging or brick trowel.
  • Crow or wrecking bar or the awesome ‘Roughneck‘ ceiling killer!
  • Pick axe (optional but useful for getting the old lathes down if you don’t have the Roughneck).
  • Clean up gear. Shovel, sweeping brush, dustpan etc and vacuum cleaner (preferably not the missus’s best one!).

Other gear that you may need

Additional things to consider…..

The mess…..

removing lath and plaster ceilings gets a little bit messy

Did I mention that removing lath and plaster ceilings can get a little bit messy.........?

It gets messy?……Oh yeah. It gets really, really, really messy. Seriously, it makes so much dust that I recommend that you remove everything from the room and seal off the doors with masking tape before you start. (Oh, and in case you were wondering, this kitchen was coming out. You can also just make out the trestles which, when coupled with scaffold battens made a perfect working platform for removing this high ceiling).

All that mess comes from dust that accumulates on top of your old plasterwork and from within the plasterwork itself. The dust is very fine in particle size and it gets everywhere, really, I mean it, everywhere!

If you have to sheet down some stuff, I would recommend that you include a polythene layer as the dust is often fine enough to go through the average dust sheet. Don’t ask me how I discovered that little gem!

Lighting

Once the room is cleared and sheeted down, including the floor, you may need to install your temporary lighting and remove any light fittings in the ceiling and make safe any wires that you disconnect (don’t forget to isolate the supply first!). Obviously if you tackle the job in broad daylight and there are windows……

Ventilation

Bit obvious this one, but you should open any windows if you can and don’t forget your dust mask!

Step by step guide to remove your lath and plaster ceiling….

Removing a lath and plaster ceiling is a three stage process (assuming that you are removing it from underneath). Read removing lath and plaster from above if applicable.

  1. Remove the plaster using a claw hammer or similar and a stout trowel. Working in front of yourself, tap the plasterwork with your hammer to break it up and if it doesn’t drop away, keep tapping it and then either use the claw on your hammer or lever the plasterwork off with the trowel. On really poor ceilings the trowel can be slid underneath the plasterwork and large pieces can be levered away. NB: It’s really important to clear away at the end of this stage when all the plaster is on the floor. You don’t need to sweep up necessarily, just get the big stuff cleared away using a shovel (otherwise the next stage will make a huge pile of lath reinforced plaster that is a bugger to clear up!).
  2. The next step is to remove the laths. I usually use a ‘pick axe’ of all things! I slide the blade through a few laths and then place the head of the pick-axe onto the bottom of a joist and lever down large sections of laths. You might want to start small and use a claw hammer or pry bar (crow bar). The laths usually break into smallish sections. I can recommend the ‘Roughneck‘ bar though, it makes the job easy.
  3. The final step is to remove the nails (apart from clearing up!) that were holding up the laths. This is usually fairly tedious and time consuming as they are very numerous and rusty. Oh, and you must not miss any, not even one. Believe me, you will curse  when you are plaster-boarding if you try to put a board up and there is a nail in the middle somewhere! Sometimes you can pull them out with a claw hammer or pry bar, sometimes they snap off sideways with a blow from the hammer and sometimes you just need to hammer them in! You’ll work out what’s best for your job quickly enough.

Time for a cup of coffee and a break to let the dust settle :-D .

Back so soon? Right, next is the boring clearing up bit.

  • Start with gathering up all the fallen laths, breaking up any long lengths and put into rubble sacks, skip or wood pile for burning.
  • Now you will see lots of plaster on the floor again. This is the mortar (snots, nibs or keys) that was sitting on top of the laths after being pushed up through the gaps in the laths to provide a key for the plasterwork. Scrape up the mortar with a shovel or dustpan and remove again.
Did I mention the dust when taking down a lath and plaster ceiling

Did I mention the dust when taking down a lath and plaster ceiling.........?

  • That leaves the dust. This can be swept up and bagged for disposal. You might want to try minimizing the airborne dust by damping down with a garden sprayer, but I’ll be honest, it is not that effective and the existing mess will be considerable anyway.
Lath and plaster and nails all removed and celing is almost ready for plasterboards

Lath, plaster and nails removed and ceiling is ready for plasterboards (no its not raining, just that dust again!)

Now you are ready for re-boarding with plasterboard, but first you will probably be getting the electrician to install new cables for those fancy new down-lights that you want!

  • TIP 1: Don’t forget to grab a pencil and put a vertical mark on the wall about an inch and a half long (40mm) that indicates where the center of the joist is. This makes finding your fixing point so much easier when you are boarding.
  • TIP 2: If the ceiling joists are anything other than straight across along the whole length, i.e. if there is any ‘trimmed’ areas that won’t be logical once the plasterboard has been offered up. Consider taking photographs of the joist layout; you’ll be glad you did if you get stuck and can’t find anything to fix to once you are boarding!
  • Tip 3: Now is a good time to check the joists for ‘flatness’, extra timber can be fixed to the joists to level up slopes or dips etc at this stage. Some people even ‘cross batten’ the ceiling with 2″x2″ timber at 90 degrees to the joists..

Hopefully that gives you a good understanding of what’s involved in taking down a lath and plaster ceiling or even how to repair your plaster and lath ceiling. Make no mistake, tackling lath & plaster is not a decision to take lightly and certainly not a job to attempt yourself, unless you can tolerate a heck of a lot of mess and drama for a few hours.

Related useful information

Removing a lath and plaster ceiling from above

I’ll briefly mention removing a ceiling from above, as it is a popular method if you have access to a ceiling from above, especially on a full renovation job of an empty house.
Working from above you can push the whole lath and plaster ceiling down into the room below, using a shovel, sledge hammer or even their boots. Simply tap the back of the laths close to and either side of the joists with your preferred tool (I recommend a lightish long handled 7lb sledgehammer)

I don’t use this method as I find that the lathes and mortar become all mixed up, making the heap of debris very difficult to clear up. Arguably though, I can see the merits of working from above, however, great care must be taken not to fall through the joists. For this reason alone I would NOT recommend removing lath and plaster ceilings from above, unless you are a pro, but then you wouldn’t be reading this would you :-)

My Top Ten Ways to Repair Lath and Plaster

This is a short summary of some of the ways you can repair the lath and plaster in your home, depending upon the look you want to achieve, the time you want to spend on it and of course, your budget.

  1. Re-decorate as it is. Vacuum to remove dust, (wash down, if required) and then re-decorate with suitable water based paint. Not a good repair if the plasterwork has gone beyond the cracking stage, i.e. sagging badly. Depends on original plasterwork 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: Potentially dangerous and possibly very short term solution for damaged plasterwork. Not a ‘flat’ finish. Shows imperfections!

  2. Fill the cracks and blemishes. Scrape out all cracks and vacuum out loose material. Fill cracks and small blemishes with decorators’ filler using a suitably sized scraper or drywall spreader. Gently sand the filler flat and vacuum all dust away. 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.

  3. Use thick lining paper. Scrape out and fill cracks as No.2. Glue a thick grade of decorating lining paper to the plasterwork. Re-decorate.
    • 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.

  4. Glue sagging plasterwork back into place. Plasterwork can be ‘glued’ back into place by drilling holes in the plasterwork, vacuuming out the dust and injecting a suitable adhesive. The plasterwork is then gently pushed back into place and supported until the adhesive dries.
    • 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 difficult for an effective DIY repair.

  5. Expose the 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. 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.

  6. Over board with plasterboard or sheetrock. Find the frame or ceiling joists, mark their position on the wall and then over-board with plasterboard / sheetrock using long (60mm to 75mm) drywall screws into the original timberwork. Board joints are then taped and filled if tapered edge drywall is used or skimmed with finish plaster if square edges boards are used. One of the most common methods to ‘repair’ a lath and plasterwork. If 25mm x 50mm battens are used first underneath the joists, this becomes a good repair as it secures the old plasterwork and allows new wiring and insulation.
    • 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. Loses that period feel.

  7. Remove the plasterwork and lath entirely.Replace with plasterboards / sheetrock. Mark positions of all joists and timbers then fix 12.5mm plasterboards to the underside of the original joists using 38mm drywall 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.

  8. Re plastering keeping the original laths. Removing the existing plasterwork entirely and if the lathwork is sound, re-apply the three coat plasterwork, two base coats and a thin finish coat.
    • 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.

  9. Heritage quality.Fully support the plasterwork from underneath on blanket covered timber on props or staging. Working from above, gently remove all loose debris, old keys or nibs and dust. Employ one of the various systems available, for example 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: Arguably not a DIY proposition due to care needed to preserve original features without damage.

  10. Buy a newer house.Sorry, I couldn’t make ten and nine ways to repair your lath and plaster just didn’t sound right. Any ideas for number ten are most welcome…….
    • 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’ (not sure what that makes me as I read well over 100 a year!). So, here are some books I found useful in my work on old houses, to get you started!

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! (it’s a nice way to say thanks for the guide if you buy, as amazon chip in towards my coffee bill!)

 

  1. old house handbook

    Not destined for the coffee table........

    Old House HandbookA 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 208 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 minimalistic, 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.

  2. book about the maintenance of historic buildings

    maintenance of historic buildings

    Maintenance of Historic Buildings, A practical Handbookby 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 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.

  3. damp houses a guide to the causes and treatment of dampness

    A damp house is a dying house......

    The Damp 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.

  4. A step by step guide to using natural finishes in your old house

    Guide to using natural finishes

    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”.

Lastly and most importantly….

Your Health and Safety.

Lets keep this sensible and I’ll assume that you have plenty of common sense and a reasonable ability regarding DIY.

      • Any electrical light fittings should be removed by a competent person, always isolate supplies and make any exposed wires safe. If in doubt get a pro in.
      • When removing a lath and plaster ceiling, there is going to be a lot of debris flying around as laths are springy things and can flick bits of plasterwork into your face with some force.
      • You will also get covered in dust.
      • Rusty of nails can be sharp, as can broken bits of plaster lath.
      • Old plaster dust can irritate the skin, especially if sweating.

So, the bare minimum that I wear when taking down and clearing up a lath and plaster ceiling or wall for that matter is:-

      • Eye protection, Goggles or safety specs (essential)
      • Respiratory protection, Dust masks or preferably a proper face mask (essential)
      • Sturdy platform to work from, minimum would be strong stepladder, better would be builders trestles and scaffold battens. (essential)
      • Stout footwear, preferably with steel toecaps (pretty essential)
      • Gloves (pretty essential, depending on how ‘tough’ you are!)
      • Disposable ‘cover alls‘ (one piece suit) to cover everything, the spaceman type! (optional but nice)

If you don’t have any safety gear then, Screwfix or Tooled Up can supply you and don’t be tempted to skimp on safety gear, nothing costs more than a few pounds! You wouldn’t risk your eyes for a fiver would you? (read my post about eye injuries if you need convincing).

Endnote….

Lath and plaster carpet

lath and plaster carpet from bev hisey

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…

As usual this page is a work in progress so feel free to leave comments to tell me how to do it properly :-)

Stay well

37 Responses to Thinking About How to Repair or Remove your Lath and Plaster Ceiling?

  1. Ian says:

    Oh how true Katie, but sadly it is a fact that the majority of folks owning an older house will not replace lath and plaster with lath and plaster. The skill set within the building industry just isn’t there anymore sadly and the cost would be prohibitive for many.

    Personally over 30 years I’ve never seen a plasterboard ceiling cause problems with interstitial condensation as plasterboard is reasonably permeable. Personally I can never see the point of vapour barriers etc in an old place but you often find them as you say as part of well intentioned repairs along with ‘skimming’ everything with modern plaster. If only these guys realised how easy it is to use old lime based products!

    I recommend these days that folks follow the USA style of using tapered edge plasterboards because then you don’t need the hard layer of plaster. Just fill the joints and screw holes and you’re done. Much more breathable too.

    But cement now, that is the biggest problem causing moisture related problems in old lime mortared properties in my experience.

    I’m interested in your comment that boarding nearly causing a floor to collapse? How so? Normally the additional load of a 13mm plasterboard and 3mm skim shouldn’t stress floor joists unduly, unless of course they were undersized or affected by woodworm or rot.

    Old buildings. Breathability (no blooming cement!), ventilation and lots of lovely heat! Not a cheap combination but a happy one.
    Thanks for dropping in Katie, good luck with your projects.
    Ian

  2. Katie says:

    I would advise anyone with an old building to think very carefully about the law of unintended consequences when adding new building materials to an old building, such as over boarding with plasterboard. New materials tend to be impermeable to vapour and interfere with the way a building breathes. We have spent thousands of pounds ripping out well intentioned re plastering repairs and boarding which nearly caused the floors to collapse and gave significant problems with condensation. Appearance isn’t always going to match modern design in old buildings.

  3. Ian says:

    Hi Dave,
    As they say, you learn something every day. Not heard about the possible risk of Anthrax for construction workers active on old buildings. Be interested in the HSE inspectors comments, since there have been no recorded cases in the past 20 years among construction workers. 20 years seems a very round figure too, it may be that this is when records began so in fact there may be no recorded cases!

    Difficult to imagine guys taking hair off known infected dead/live animals in days of old, but now I think about it, I have no idea how horse hair was harvested for construction work!

    SPAB are great aren’t they? I have called a few times when I wasn’t sure about the best way to proceed, (usually related to lime mortar) and they have always been very helpful.

    We still have a long way to go to educate people about allowing buildings to breath! Such a paradox here (in Norway), I have been doing a little new work lately and everything here has to be literally airtight. Gaps around frames are filled with insulation and then taped over before trims, architraves and skirtings etc are fitted. My Dad commented, ” so you pay lots of money to make the house air tight, and then you pay a load more money to install a ventilation system…..Hmm” He has a point. But then it does get down to minus 25 regularly here, so a draught can be expensive lol!

    Thanks for taking the time to comment!
    Stay well
    Ian

  4. Dave says:

    A couple of points

    I have had long discussions with safety officers lately about the risk of possible Anthrax in hair reinforced plasters, particularly those from before 1900. English Heritage have an excellent guide available online

    To those who are asking to use adhesives, just remember that lath and plaster is designed to breathe, that is, it is supposed to pass moisture, which also protects the timber lath and the timbers it is attached to. Applying any sort of adhesive or indeed modern paint will form a membrane which blocks the passage of moisture. Only breathable mineral paints or limewash should be used.

    SPAB have some very good web pages on this subject too.

  5. Ian says:

    Hi Marc,
    Hmm, another one that often comes down to personal choice and your tolerance to, how can I put it, non cleanable surfaces. Many people stiff brush the brickwork and then vacuum the heck out of it until the wall is relatively dust free. But I am sure that as the wall warms up and cools down the bare brickwork, especially old lime mortar brickwork, must shed some dust as time rolls by.

    There are a couple of proprietary brickwork sealers but they are mainly intended for use outside. However there is no reason not to use them inside and they sometimes exaggerate the brightness of the bricks, making then look wet even. I wonder if a clear varnish would give a mat finish?

    Us usual, try a test patch first. Possibly with the Unibond type sealer as it’s cheap and you probably have some (you say that you tired it and it dried grey??). If you are not happy with the effect it’s time to take a trip to the store. The problem is that whatever you decide to use there is no going back! Undoing ‘painting/sealing’ brickwork is a big job. Incidentally have you considered painting the wall? I love to see painted brickwork as it has some character but not too much as the paint tones it down. Just a thought!

    Sorry not to give you a definite answer, it does come down to personal choice in the end.
    Thanks for stopping by Marc, good luck with the project, maybe you could post a pic or two of the finished result?
    Cheers
    Ian

  6. Marc says:

    Hi Ian,
    wondering if you have any experience with red brick walls (interior). Rather than plastering the whole room I am hoping leave one of the walls exposed. Insulatin etc is not an issue as it’s a mid-terrace house, but I am unsure as to how to finish it. I have used a unibond coat to reduce dust as I remove excess plaster but once it dries im sure it will look very grey again rather than the red that im hoping for. any idea or even a point in the right direction?

    Much thanks
    Marc

  7. Ian says:

    Your welcome Kim, nice to put my experience to good use online instead of onsite! The batten doesn’t need to be very thick, 25mm is ideal but you could go as thin as a 19mm tile lath if space is tight. Arguably 2.3m is a sensible minimum ceiling height (unless its as old cottage where anything goes!).

    You can make a good job screwing straight up to the existing lath and plaster, you just need to be careful when screwing the boards up. I wrote about this on my new site (I am trying to move the building related stuff to a more professional setting!) at How to use drywall screws properly and close up the spacing to say 150mm or so (instead of the more usual 200mm or so).
    Good luck Kim
    Ian

  8. Kim Cheung says:

    Hello Ian. I like your idea of cross battening. It will lower the height of our already low ceiling, but we’ll soon get use to that. After this ceiling there are another 2-3 smaller ones that need repairing. With the helpful advice offered in your website I feel much more confident in tackling those repairs now. Thank you, Kim

  9. Ian says:

    Hi Kim,
    Lovely Artex….. fashion has a lot to answer for doesn’t it!! Of course flat ceilings look much nicer, we can all see that now. You are right to be worried about pushing and puling the ceiling too much. The nibs that hold the plasterwork up can be quite fragile in ceilings over a hundred years old. Looks like overboarding might be the easiest option for you. Maybe with a tile lath counter-batten if you want to make a really good job as the battens will hold up the existing lath and plaster indefinitely. Although if you are careful and use plenty of correct sized drywall screws (penetrating at least 25mm into the joist) e.g typical: 12.5mm plasterboard + 25mm L & P + 5mm skim and Artex + 25mm min into the joist equals…67.5mm, so I would try to get 75mm drywall screws. Don’t forget to leave the screws no more than flush with the board. If you drive the screw in past the paper, virtually all holding power is lost. Drywall screws have a little sharp ridge on the back of the head which needs to bite into but not though the paper on the plasterboard to hold firm. Coo, going on a bit now!!
    Let me know if you need a better answer!
    Cheers
    Ian

  10. Ian says:

    Hi Marc,
    So sorry for the delay, been away on a mission abroad with limited access. It’s probably too late now but I am trying to picture the layout of your place. It sounds like it is a room in the loft? If the ceiling is the actual roof joists then you will need to leave a ventilation gap over a rigid dense polystyrene type insulation. This can be quite complicated to explain as it is vital that the air can flow in and out properly to prevent damp in the roof structure. The local building office will advise you for free so you can always give them a call. If I have misunderstood, get back to me and I’ll have another think!
    Thanks for stopping by.
    Ian

  11. Kim Cheung says:

    Excellent website with lots of very practical advice. I’m still undecided what to do about our lathe and plaster ceiling. It’s reasonably sound. The previous owners have already re-plastered the ceiling, and I guess at a later date Artexed it too. Probably trying to cover over the cracks. Patterned Artex is an acquired taste, and I personally prefer ‘flat’ ceilings. I’ve tried to remove the Artex but that really is a difficult task, and hazardous due presence of asbestos in pre-1990’s Artex. Also concerned that the amount of force I’m using to remove the Artex will weaken the lathe and plaster ceiling. I then considered having the Artex plastered over to give a flat surface finish. I have my doubts about re-plastering; I suspect cracks will start to reappear again after 1-2 years. After reading your comments I think the over-boarding with drywall sounds like suitable (or compromise) solution. Removing the lathe and plaster entirely might be the better option but besides the mess and dust, there’s the asbestos in the Artex to consider. Yours thoughts on this would be very welcome. Thank you, Kim.

  12. Marc Higgins says:

    I have removed lathe and plaster from my third floor ceiling (roof joists) is there any particular insulation or plaster board I should use? certain thickness or anything or leave room for ventilation I am unsure! The third floor has a window and open plan from the stair case!
    Appreciate any insight!!
    M

  13. Ian says:

    Thanks for commenting Bryce, yes the ‘magic’ plaster washers. I thought about them, but in all honesty I have never got on with using washers! I find that it is all too easy for a pro, let alone a keen DIY guy to screw them up too tight resulting in an “elephants foot” in the ceiling! Of course this also negates the whole process as the repair…..well, isn’t!

    So, I talk about gently supporting the ceiling whilst the adhesive cures. My personal preference is to use the lightweight adjustable props, you know the ones that look like a huge caulk gun. These are gentle enough with a timber spreader on top to push up the ceiling without breaking it. For spot repairs you can cut a 600mm x 600mm square of 12mm plywood. Drill 50mm holes close to the four corners and then prop it up to the ceiling. Holes can then be drilled into the ceiling through the 50mm holes in the plywood and adhesive pumped in, knowing that the ceiling is fully supported at that point and more importantly not too stressed.

    Each to their own though, this might even be that I am too mean to buy the special washers and prefer my reusable methods, you know how contractors are I am sure :-)
    Thanks again for commenting Bryce, dead jealous of your domain name mate!
    Cheers
    Ian

  14. The #4 on glue misses the key ingredient: specialized plaster washers to “pull” the lath & plaster together for a good bond. These washers are removed after the glue is dry.

  15. Ian says:

    Thanks James, hope this is still useful, we have been away and not had time for the internet much!

    Hmm, unibond, some do use it but of course it wasn’t used historically, the mortar doesn’t really “stick” to the lath as such, but rather wraps around it to form a key, hence the plaster nibs that push through being so important.

    So, it fully commit myself, you don’t have to unibond lathes but it doesn’t hurt either, there you go clear as mud!!
    Good luck with it James.
    Ian

  16. James says:

    Thanks for a great page. After the ceiling has been taken down would it be best to Unibond PVA the lathes before applying the base coat lime/fibrous plaster?

  17. Ian says:

    Thanks Bryce! I have it at number 4, but I admit to having never used the adhesive method. I think what frightens me, is the difficulty of assuring that all the loose bits are secured, from guarantee point of view.

    Its a bit like a job I had years ago, to chop out and replace a dozen or so rotten bricks in a wall. Years later the client commented that I had made a poor job, as there were still rotten bricks in the wall. It was obvious to me that the remaining poor quality bricks in the wall will continue to erode over time creating newly rotten and spalling bricks; but he didn’t get it. I had been and therefore the wall should be perfect. Duh! You can’t argue with that kind of logic.

    Thanks for stopping by Bryce, hope the page was helpful!
    Cheers
    Ian

  18. The glue injection techniques could be your #10 (as typified by the Big Wally’s Plaster Magic products)

  19. Pingback: …….But instead I ripped my house apart? « I Should be Marking….

  20. Ian says:

    You’re welcome Elisabeth, glad you liked the page. Good on you for having a go! It’s not too difficult is it, just messy and a bit awkward to clear up.
    Thanks for stopping by and good luck with the rest,
    Ian

  21. Elizabeth says:

    I enjoyed your site a lot and find it very well done. But I’m glad I didn’t read it before taking down my ceiling as it may have discouraged me. I took down a ceiling and an interior wall that was not original to the house. The ceiling had a 2×3 foot hole in it and cracks all over it. It was 91 years old. I have more ceiling to go and was looking for tips on tools to use and am pleasantly surprised that I have been doing the right thing, ie. a lightweight claw hammer and I tap it when it doesn’t just pull. I am not looking forward to the dust again, but it must be finished. Thanks for your information!

  22. Ian says:

    You’re welcome!

    Good luck, it is a serious decision to take on an old house. You’ll know if it feels right for you.
    Stay well
    Ian

  23. Franklin says:

    Ian,
    Thanks for giving us such a complete answer. It was very informative. You asked if the ceilings were lathe and plaster, they are. They seem to in good shape. All the cracks are in the walls. We have more research to do before we can decide if this house is for us, but you’ve been very helpful. Thanks.

  24. Ian says:

    Hi guys,
    No problem, I like to help! Right, lets go through the questions….
    1. Removing the lath depends on how flat it is and if you need to remove it to put insulation behind. Mostly new wiring can be done by bashing a few holes in the lath where needed. You might also need to think about the new thickness around windows or doors (so that the trims/architraves/etc) have a chance to go back on without too much extra joinery work. I believe that the lath used in the States is much better than the rough lath used in the UK as well. You would almost never sheet over English lath as it is rarely flat enough. Some people remove it simply just to get back to ground zero and to make sure that their walls are as good as they can be.

    2. Not necessarily, sections or ‘zones’ can be replaced, as long as the electrician knows the eventual plan, he/she can make provisions for different sections to be replaced later. You definitely don’t want any junctions that are hidden in the walls but new cable can be coiled up in the void waiting for the next round of ‘de-plaster and lathing’. Then the new wires are there ready for extending into the new space. If you explain your thoughts to your electrician he will understand, if he is a good lad!

    3.Sure, wiring is replaced in ‘finished’ houses all the time. Wiring can be pulled through and replaced and new sections added with some small plaster repairs to do. Depends on how many new ‘runs’ you need etc.

    4.Weeelll, expensive is all relative isn’t it!! One mans expensive is another mans reasonable! When I say expensive, I mean when compared to carrying out a few patching repairs or lining the wall with thick paper. And of course cleaning up the mess does take time, if you are paying skilled men etc.

    5. Time wise, it doesn’t take a horrendous amount of time to actually remove the plaster and lath, certainly a few hours of mad bashing will make a big dent in the job, the time is doubled though by the preparation and following clean up. Without knowing your skill level I hesitate…….but for me, yes, we could do a room in a day. There you go, I have said it…….comment here after you have finished and it took a week……..:-)

    Hope that helps, please let me know how you get on if you decide to take the plunge!
    Ian
    p.s. you don’t mention the ceilings, are these also lath and plaster??

  25. Franklin says:

    Ian,
    Thanks for the great article about lathe and plaster. My wife and I are thinking about purchasing a 1930′s house with lathe and plaster walls. It still has the old knob and tube wiring. It’s a great house, but these two things are a little intimidating. The plaster on some of the bedroom walls is cracking and sagging; not horribly but we would need to deal with it. Because of the wiring, we are thinking about simply removing the lathe and plaster walls, fixing the wiring and putting up sheet rock. But we have a few questions we would really appreciate some help in answering. 1) Do we need to take down the lathe and the plaster or can we just remove the plaster and sheet rock over the lathe? Why do these always seem to be done together? 2) It doesn’t sound like you are also an electrician, but maybe you can tell us if we have to do all the walls, in all the rooms at the same time in order to update the wiring? 3) Also, have you ever helped someone update their wiring without removing the lathe and plaster walls? 4) In your article you said that removing the lathe and plaster and replacing it with sheet rock was expensive. Is this expensive because of the labor involved in removing the lathe and plaster, and disposal of the debris? What if my wife and I did all this ourselves. Would you still say it is an expensive option? 5) Lastly, how long is the process of taking down the lathe and plaster off an average bedroom? Can you do a room in a day with two able bodied people working? Boy, this is a lot to ask, but we would really appreciate the help. We need to make a decision on this house, but we’d like to go into it with our eyes wide open. Thanks!

  26. Ian says:

    Your welcome Shippy! Glad that the page helps you a little, thats the idea! It is bad taking lath and plaster down, but the end result will make up for it and you know that the repair is a permanent improvement. Good luck with the rest of the project!

    Thanks for stopping by, feel free to forward the page to anyone else you think will find it useful.
    Stay well mate,
    Ian

  27. Shippy says:

    WOW! Thanks for this Ian, it’s an excellent blog for someone going through the dilemma of re-ceiling my 1880′s house in South Australia. It’s a single story central hallway four main room design.

    I (think I) have decided (60%) to remove the lath and plaster – it’s probably not too bad as far as plaster goes – but I feel if I don’t do the whole 9 yards now, I’m going to regret it and feel there is the potential for more issues later.

    Unfortunately I’m currently living in the house, so disposable drop sheets and plastic a-plenty in an effort to stop the dust. One of the reasons for re-doing the whole ceiling is the wiring is a little dodgy in some places, and also gives me a chance to clean up the roof space. I’ll be working on the front two rooms first, then finally the middle bedroom as it appears the lounge room has had a re-do fairly recently.

    I’ll probably take a bit of a photo diary sometime of my process – I’m hoping it won’t take too long. I’ll put a follow up comment if I do end up changing my mind.

  28. Ian says:

    Your welcome Elisabeth! Glad to have been useful.

    Let me know if you need any specific help or if you have any photos you want to share, always on the look out for a good story!

    Good luck with the new house, I am in a house built in 1968 at the moment and am really missing my ‘old stuff’!!
    Thanks for stopping by,

  29. elizabeth oliver says:

    Thank you so much for this site and the great info. You helped guide me so much! Just bought an 1865 home . I’m a little nervous . tHanks for all!

  30. Ian says:

    Hi,
    Sure, screwing the sheetrock into the joists is the normal ‘new build’ way of going about it. My only comment would be to see how flat the joists are. If they are pretty good, say + or – 5mm (up to a 1/4″) then you should get a pretty flat ceiling going into the joists. If the joists are all over the place, you could consider runing some timber crossways to level it all up a little, packing where necessary.

    Insulation on top of sheetrock is OK, but if it is a ‘cold’ flat roof you should probably have a ‘vapour barrier’ first. (see image) or do you have ‘foil backed’ sheetrock in the states? In the UK sheetrock can be supplied with a thin aluminum foil on the back that replaces the thin polythene vapour barrier. Vapour barriers should always be on the ‘warm’ side of the insulation. You would be amazed how many people think that the ‘logical’ place for polythene in a roof is on the top…….
    Image of an insulated, example roof

    Re the textured ceiling. Several ways of doing it if it is similar to the type we have here. You can hire machines for physically removing the stuff, there are chemicals that soften it and then you can scrape it off and thirdly, plasterers sometimes scrape off the biggest texture, seal it with a PVA adhesive/primer and then skimm the whole lot with a think layer of finish plaster say 1/8″ thick.

    Do you have any pictures of the window head in the other room? Just that if the window frame ‘head’ is thick enough, you could take the sheetrock right into the reveal and up to the window frame, then fit a bead across the top of the frame, (if I have pictured this right in my head), geo differences may apply here lol!

    Another way you could do it, is to sheetrock the ceiling but leave a ‘box’ out, say 4″ around the window area, creating a little ceiling ‘well’ around the window, then you only have a tiny bit of the original ceiling showing that should be easy to tidy up. The inspiration for this method stems from holding back sheetrock from existing decorative cornice/coving/mouldings a little, when overboarding the whole lot. It just looks like an extra profile on the cornice, once painted up it looks like it is supposed to be there.

    Have I explained that enough to get a mental picture!!??

    Thanks for stopping by!
    Cheers
    Ian

  31. Washington DC Row House 2 says:

    Had another question as this great step-by-step got me thinking about our other (much larger) plaster and lathe ceilings. The ceilings in our first floor (and 1 upstairs bedroom) have that circular texture pattern which I think was done on the plaster with a brush before it set. Not sure if it’s original, or if it was another coat done later. But whenever it was done, it was done extremely badly, and it also has been patched over the years and looks hideous! It seems to be stable and not sagging excessively. In one room we can go over it with sheet rock, but in another there’s not enough space above the window frame to fit additional sheet rock. What options do we have for keeping what’s there? Could the rough texture be sanded down, or is that just not practical? Appreciate any thoughts/experience with old textured plaster ceilings.

  32. Washington DC Row House says:

    Just finished pulling all the plaster and lathes off the bathroom in our nearly 100 y/o little DC Row House. The ceiling was “easier” (but still quite dusty!) as the original plaster had been taken down and sheet rock was installed around 1990 (based on date on back of the old sheet rock). Whoever did this remodel didn’t take the lathe down, they just sheet rocked over it. I plan to remove them, but I am wondering if best to screw new sheet rock to the joists, or if some sort of supports or hangers should be attached first going perpendicular to the joists? Also, above this ceiling is about a 1-2ft crawl space and above that the “flat” rubber roof over wood. There is no insulation, but we will likely insulate this bathroom before putting up the new ceiling, and eventually the whole house next time the roof is done (we have a few years at least). So, to recap, main questions are: is it ok to screw sheet rock right to the joists? Is it ok to lay insulation on top of sheet rock? Sorry if this is a bit rambling!

  33. Ian says:

    Had to smile today. I noticed that someone found this page using the phrase

    “how to remove laughing plaster”

    Oh, the irony…….there will be no laughing taking out your lath and plaster………..

    At least, not till its all finished :-)

  34. Ian says:

    Thanks! I even had a shot of myself afterwards too, but I decided not to include it in the end, as I didn’t want to frighten everyone on the planet from ever touching a lath and plaster ceiling ever again lol!

    It is without a doubt, with the possible exception of working on old drains :-(, that we do as builders. And of course, because it is not our houses we have to make sure that the dust and mess is 100% cleanable. This is one mess that the lady of the house cannot volunteer to clean up with a vacuum cleaner!!

    Sheetrock certainly has revolutionized the way we work inside, its so stable can can be used in so many clever ways too.
    Thanks for stopping by Ellie!

  35. Ellie Cutler says:

    Thanks for the comment! That link is amazing and will make future work SO much easier!

    The picture of the mess made me laugh outright. I was reading along and came to the picture and seriously almost choked on the water I was drinking because it reminded me so much of our project. OY! We had no idea it would be so messy. On the bright side…I appreciate sheet rock so much more now! :)

  36. Ian says:

    Someone asked me today, “what about if there is cornice work around the ceiling edges?

    It’s a good question and the answer is that you have a little more work to do!

    Firstly, you need to determine if the coving was cast in reinforced sections and then fixed into place in sections or if it is the rather more unusual ‘run’ coving or literally cast in situ. A specialized job these days and so you would be wanting to keep this if you have it.

    In most cases you could still remove the ceiling lath and plaster, but first you need to form a break line or cut around 3″ or 75mm away from the coving. You should only have to go through the plasterwork initially. I use a multitool and have the Bosch PMF 180 E Allrounder which cuts through the lime plasterwork easily.

    Greater care will also be needed when removing the lath and plaster generally. Work carefully once you get close to the cornice and swap the big tools for just your claw hammer to remove plaster and laths. Make sure that any lath you are removing doesn’t wander across and underneath the cornice work or you could pull down a section when you rip out the lath!

    Finally, you will probably have a difference in thickness between the existing lath and plaster and the new plasterboards going up. This difference is often more that half an inch.

    We mostly rip down some thin timber (the difference between the two ceiling thicknesses) and glue and screw it to the underneath of the joists to ensure that the new plasterboards finish at the same level as the original lath and plaster. If the difference is only minimal, you could ‘feather’ in the edges over a foot or two with plaster to ‘hide’ it, or you could plasterboard right up to the cornice and fill vertically down to the front edge of the cornice (bit tricky and depends on the profile of the edge of the cornice)

  37. Ian says:

    Reading comments about this topic, is proving a good education for me, as I learn about the differences between lath and plasterwork in the UK and the way that it is done over the pond in the USA.

    Apart from the fact that in the UK plaster and lath was mostly used on ceilings, apart from the odd first floor partition, UK lath appears to be mostly split or riven.

    I hadn’t appreciated this. Riven lath was used before sawn lath and is somewhat stronger as it was split with the grain from Oak, Hawthorn or Chestnut etc. riven laths were even used to fix reed to a timber structure before plastering.

    Whereas, in the states, lath seems to be mostly sawn and therefore much more uniform in application.

    I only note this to point out that there are additional methods of fixing sagging plasterwork using injectable adhesives on sawn lath, that I feel may not be so effective on the UK’s random riven lath.

    I do of course, as always yield to higher knowledge!! My experience only covers UK stuff so I would be delighted to hear from anyone with experience of working on sawn lath and plasterwork and the differences in repairing them.

    Stay well

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