Renovation Works completed and now I have damp patches around sockets, what should I do?

As featured in the Sunday Times, November 21st 2021


Some ten years ago I renovated a cottage that was built around 1860 of mud and stone. Recently there have been a lot of damp patches appearing around sockets and other fixtures. I’ve been told I used the wrong plaster board during the renovation.
Any advice on how to rectify the problem?


It is very difficult to say without knowing the specifics on what damp proofing works were carried out ten years ago during the renovation. It’s important to highlight that as with all retrofit dampDamp sockets solutions there is a certain life span on these products. This life span is usually ascertained by the products manufacturer and the product warranty and can vary in accordance with this. One would hope to get up to ten years from most damp solution products although some can be up to 15 years.

Our surveyors have encountered this specific issue on a number of occasions particularly in older properties.

A house that was constructed in 1860 with random rubble walls is almost certainly not going to have a damp proof course (DPC) incorporated at the base of the wall. As a result, it is highly likely that the lower section of the walls is suffering from rising dampness. Rising damp is ground moisture that rises up the wall through capillary action. During your renovation project it sounds as if you lined the wall with plasterboard and while this might improve the appearance of the wall, the fact is that the wall remains damp behind the plasterboard. It is also possible that a bonding compound was used around the sockets to stick the plasterboard to the random rubble wall. The damp patches that are appearing around the sockets may be a result of dampness that has transferred from the damp wall, through the adhesive dab and onto the face of the plasterboard slab. Metal socket boxes can also rust and cause staining and plastic boxes should be used as an alternative when there is potentially damp walls. The bad news is that the likely remedy will involve removing the existing plasterboard and carrying out some damp remediation works.

It is always important to diagnose the specific source of the moisture and rule out all other potential sources using standard testing methods by professionally trained and qualified surveyors. This approach is essential to ensure that you spend wisely and don’t waste money on solutions that may only add to the problem.

Colin Nolan, Chief Surveyor, Dampdoctor.