Lath and plaster ceilings and walls were a hallmark of homes built from the 1700s to the early 1900s. And if you live in a period home, they could well be hiding in plain sight. If unsure, there are a few simple tricks that you can try to help identify what type of ceiling you have.
The experts recommend leaving them if at all possible. But they may need careful repair to restore their strength and charm. In more serious cases, they might need to be replaced with modern plasterboard. Here, we explore repair options and learn what it’s really like to live with and safely update these timeless features.
Matt Clare is the owner of Gower Plastering Services, a South Wales plastering contractor with over 15 years’ experience delivering internal and external plastering work for residential and commercial properties.
Lath and plaster ceilings explained
Matt Clare, Owner of Gower Plastering Services, starts by saying, “Lath and plaster ceilings are the original ceiling construction found in most homes built before the 1940s.”
He adds, “Before plasterboard became the standard in the mid-20th century, this was simply how ceilings were built.”
Article continues belowLath and plaster ceilings are made up of laths – thin strips of wood, around 25mm wide – covered in a lime-based plaster that has often been combined with coarse animal hair, such as goat or horse, for added stability and flexibility.
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How to identify a lath and plaster ceiling
If you’re unsure whether you have a lath and plaster ceiling, there are a few indicators that can help you.
Matt Clare says the age of the property is a great indicator, “If your home was built before the 1940s and the ceilings haven't been replaced, there's a strong chance they're lath and plaster.”
For a more visual clue, Clare says try your loft space, “If you can access the void above - through a loft hatch, lath and plaster will be noticeably thicker than plasterboard, typically 20–25mm,” And more tellingly, he continues, “You'll be able to see the timber lath strips.”
Finally, there is the tap test. Clare says, “Gently tap the ceiling with your knuckles. Lath and plaster has a duller, more hollow sound than the crisper knock of plasterboard.”
How to repair a lath and plaster ceiling
While they can last for hundreds of years, it is not uncommon to find old lath and plaster ceilings requiring repair during renovation projects.
Check your ceiling for sections that appear uneven or sagging, and be on the lookout for cracks as well. While none of these necessarily point to a huge issue, they may well be signs that maintenance or further investigation is required.
In these cases, you will need to decide between repairing old ceilings or replacing them entirely with modern plasterboard. While patch repair will be a far cheaper option than total replacement, if more than a third of the ceiling has failed, it is generally advised that replacement will be the most sensible option.
Small repair jobs can be done DIY. Paul Kerr, building specialist at Beatsons, explains how: “To repair smaller hairline cracks, start by raking out the plaster around the crack slightly and applying a mesh and compound filler.”
But beyond small cracks, you should consider a professional shares Kerr, “For heavier cracks, sagging or bowing, you will need a professional to ensure the job is done properly.” He adds, “Sagging is especially dangerous as it means the plaster keys have broken and are no longer holding the weight properly, leading to potential collapses.”
Paul Kerr is an experienced branch manager with a demonstrated history of working in the retail and merchanting industry. Skilled in home building advice he has seen everything from outdoor patio organisation to full rebuilds.
Should I remove a lath and plaster ceiling?
This depends, Clare says, “In most cases, my advice would be: don't remove them unless you have to.” He adds, “Lath and plaster has excellent acoustic and thermal properties that modern plasterboard simply doesn't match. It's also significantly better at fire resistance - the multiple layers of lime plaster provide a meaningful barrier.”
And there is also their decorative value to think of, “From a heritage and aesthetic perspective, original ceilings - particularly those with cornices, ceiling roses, or decorative mouldings - add real character and value to a period property.”
If you decide to remove a lath-and-plaster ceiling, be prepared, shares Kerr: “Lath and plaster ceilings generate a lot of dust when removing, and in turn create a huge mess.” He adds, “They can also contain hazardous chemicals due to old plaster using horse hair. Professionals will need to completely take over the room in question and will usually take a couple of days (or at least one full day).”
Also, it is worth noting, says Kerr, “If you live in a listed building, then you're legally obliged to seek permission before removing these ceilings. Most conservation officers will insist on repairs over replacements in most cases.”
Another option is to leave the old lath and plaster ceiling in place, overboarding the entire thing with plasterboard.
FAQ
How do I fix a lighting fitting to a lath and plaster ceiling?
If you have existing lath and plaster ceilings, you may well be wondering if you can hang fittings such as new lights to them. While this is not as much of an issue as with lath and plaster walls, it should still be thought through.
If you want to hang anything from your ceiling, it will always be best to screw directly into the joists as opposed to relying on the strength of an old ceiling.
Anyone who wishes to install recessed downlights into a lath and plaster ceiling should definitely call in the services of a qualified electrician who has carried out this kind of work before. Although it can be done, drilling large holes into a ceiling that is already a little unstable could cause it to come down or sections to fall away.
Your electrician should be able to advise you on the suitability of your ceiling and may suggest cutting a larger hole than is needed and reinforcing the area around the new light with plasterboard.
Whether you decide to keep or replace your lath-and-plaster ceiling, decorating the room can make the most of it. Check out our painted ceiling ideas, feature wall ideas and wall panelling ideas for inspiration and insight.
