single course brickwork

[cojack]

Son has moved into a 1880's terrace. Rear of kitchen is extension that was probably toilet/washhouse etc with single course brickwork.

Slight damp problem, suggested he seal extrenal brickwork with Aquaseal or similar waterproofing/silicone? when brickwork is dry. Put inside 4" stud partition with airspace top & bottom lined with plasterboard.

Are there any special plasterboards or better? Any alternative/better suggestions?

Regards

Colin

[Andrew Gabriel]

It's unlikely to be an extension, in that it was built with the rest of the house -- very common.

It's not a very good idea to treat brickwork like this. Check the pointing is in good condition and rainwater gutters/pipework is working and not spewing water down the wall. If that's OK, just assume that's as dry as you will get the wall, and design the inner leaf to cope.

4" seems excessive, and would result in a significant loss of space in the room. I would use battens, probably made from pressure treated roofing battens. Look up your local roofing supplier and see what their largest roofing batten size is, for a suitable candidate.

Use plasterboard with integral Kingspan/cellotex backing, which will prevent the wall being cold and forming damp from condensation. The ventilation behind should be to the outside, not the inside. Use pressure treated timber for the battens/studding, and I would suggest a strip of plastic (e.g. damp proof membrane) between each batten and the wall where they are in contact, so the timber is not kept damp by contact with the outside wall. Also use a strip along the floor under the plasterboard, in case the floor is damp (quite likely).