Lath and plaster walls

[Shaun M]

Hi there I’m new to the group so relatively inexperienced in period property maintenance. I’m assuming the lath and plaster walls shouldn’t sound hollow? I’m thinking it’s blown away from the stone walls which it’s covering. In fact I have come to the conclusion the walls are in fact made of cream cheese
I have read other articles where lath and plaster has been removed and walls have been dry lined. Any opinions on whether or not that would be a suitable approach for a solid stone house?
Cheers,
Shaun.

 

[mardinor]

Firstly, welcome!

Secondly, congratulations on correctly spelling lath. You would be amazed how many walls appear to contain turning machines...Though, our pedants would instead pick you up on the fact that plaster directly applied to stone walls would not need laths (these are substrates for bridging hollow areas, such as ceilings or stud walls).

Thirdly, to answer your actual question, you are correct that walls plastered onto stone shouldn't sound hollow and that the cause is likely that the plaster has blown (detached from the stone or underlying coats). However, the good news is that practical experience tells me to leave them alone. I have plenty of such areas in my house that have been fine that way for the 25 years we've lived here. Unless it's a ceiling that may fall on you, nothing bad is likely to happen. The worst that could is that the area detaches and then you can patch replaster at that point. If you do want to keep yourself busy, a simple fix is to drill a small hole through the detached area and inject adhesive or slurry plaster (assuming the plaster IS on stone). Or if it is actually a lath wall, then scraping back a divot and applying a stainless penny washer and screw into the lath works well (typically used to preserve historic ceilings). But, honestly, leave alone. Strategic procrastination is the secret of period property ownership, as others here will attest.

 

[malcolm]

If the plaster really is lime and lath then it should sound hollow. Lath are small strips of wood nailed to a stud frame with gaps between them. The plaster is pushed into the gaps and holds the plaster to the lath. If the plaster is instead directly on the stonework then it shouldn't sound hollow, but mardinor's advice is good there - intervene as little as you can.

Tanking would be a very bad idea. Walls always get a little water coming in and will only stay dry if thay water has a path out again. Tanking is waterproof and the wall will slowly get wetter and wetter until many years down the line is it soaking wet and causes damp in other places above the tanking or condensation problems because wet walls are cold walls.

It's worth reading up a bit about old houses. SPAB, English Heritage and Heritage House are all good references on line and Peter Ward's videos on Youtube are informative and entertaining (mostly about damage caused by the damp proofing industry).

 

[Lacan07]

Hi there I’m new to the group so relatively inexperienced in period property maintenance. I’m assuming the lath and plaster walls shouldn’t sound hollow? I’m thinking it’s blown away from the stone walls which it’s covering. In fact I have come to the conclusion the walls are in fact made of cream cheese
I have read other articles where lath and plaster has been removed and walls have been dry lined. Any opinions on whether or not that would be a suitable approach for a solid stone house?
Cheers,
Shaun.

Lath & plaster walls will sound hollow as they are essentially a stud frame, which is entirely different to a stone wall of course. If you tap / knock the plaster on a stone wall and its sounds hollow then yes it may have come away from the wall but as other have said if its just isolated areas I would leave well alone.

 

[CliffordPope]

Our house, mid-victorian welsh farmhouse, has a kind of composite structure on the internal walls. Those that aren't solid stone are mostly stud walls but filled with irregular flat stones loosely cemented with the biscuity stuff that I suppose is lime mortar. Then these are contained between the usual lath and plaster. The walls therefore sound hollow in places, depending on the variable gap between the outer surface and the inner stonework.
I can only guess why they were built that way - sound proofing, or to create thermal mass?

Putting up shelves or picture hooks is always a bit of pot luck. Sometimes the drill meets a chunky stone that is still anchored to its fellows, sometimes it just disappears into a void. Knocking in a picture hook sometimes meets crumbly plaster between the laths, sometimes a lath, and sometimes provokes a minor avalanche of loose stones or lumps of plaster. So anything is possible.