Damp and moisture meters

Can plaster taken down past the damp-proof course keep the skirtings wet?

Yes, plaster carried down across the damp-proof course onto the masonry below it can wick moisture up into the skirtings. The course may still be present, and the finish is bridging it. A meter on the skirting cannot separate a sound course from a plaster bridge.

Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.

What is the fuller explanation?

The damp-proof course is a barrier in the wall, usually a little above outside ground level. Plaster, render or a dot-and-dab dab that continues below that line joins the wetter masonry to the dry face above. Skirtings then swell or stain even though the original course has not disappeared. You can sometimes see plaster hard down to a solid floor, with no gap at the line of the course. A surveyor can record that detail. They cannot see the course inside the brick without opening the wall.

The Property Care Association's homeowner advice covers damp along with rot and woodworm, so the moisture path matters more than a product name. A RICS home survey does not guarantee concealed parts and does not have to hack off the plaster to mention the bridge. Replacing the skirtings without cutting the plaster back above the course leaves the wick in place. Ask whether the comment is about bridging by the finish, about high outside ground, or about both.

What should you ask your surveyor?

Did the plaster or the render continue below the damp-proof course?
Were the skirtings wet while the wall above the bridge line was dry?
Is this a finish bridging the course, rather than a missing course?

What are the typical next steps?

Do not replace only the skirting if the plaster still crosses the course.
Look outside as well. High ground is a separate bridge from low plaster.
If you need the wall opened, agree that as a further look. It was not part of the visual survey.

Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.

Also asked about this

Is a gypsum plaster the problem by itself?

Only if it is linking wet masonry to the room. The material matters less than whether it crosses the course.

Does a new skirting prove the bridge has gone?

No. A new board can be fixed onto the same plaster. Look at the plaster line, not the timber.