DIY Doctor UK DIY Forums

I am looking for some advice about damp on an exterior wall.

The area is about 1.5m x 1m.

The old lath and plaster has blown. I have removed it and have found that the stud work behind it is totally rotten.

There are several gaps in the mortar and when it rains water settles on the brick work.

The wall is under a window but there does not seem to be water coming in from directly under it.

The outside of the wall is painted.

Should I repoint the wall from the inside. I am concerned that this will not solve the problem just move it to somewhere else.

I have read about silicone water repellent. I assume that I can not use this as the exterior of the wall is painted or will the repellent work through paint. Could I se use the repellent on the interior surface.

I woulde be very grateful to anyone that could help. Thanks

Hi,
Is there earth against on the outside of the wall? If so remove it
Fill in any creaks or gaps inside and out. Also make sure the damp is not coming up via the floor.

Once you have repointed, paint the area plus a good meter either way into the dry areas with bitumin paint. We call this tanking.Apply about 4 0r 5 coats.Allow to dry after each coat.
You can either render and plaster or rebuild you stud using treated timber and fix with foil backed plaster board ans scim Ideally do the above to the whole wall affected. :)

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