DIY Doctor UK DIY Forums

I'm planning to convert the basement in my house into a couple of bedrooms and was all lined up to have it tanked out with a waterproof cavity lining and sump/pump system but have just had it pointed out to me that it isn't actually particularly damp in the basement so dry lining and additional ventilation may be sufficient.

Of the walls that I intended to line only one of them is an external wall which does show signs of damp but not excessive, there is also window on this wall which is currently boarded up allowing some water penetration which accounts for some of the damp. The room concerned is an old victorian kictchen.

Obviously it is a risk but it would save around £10k on the project. Has any one had any experience of this or any explanation to me as to why I shouldn't take this line. Also how would it effect me for building regs and when I come to sell it

I'm considering a similar project. Didn't realise that the cavity membrane system cost 10K! Have you had any further advice on this?

Before you're going to do that planned you must see to it first that the area is fully waterproof because it will be harder for you to fix it soon when it's already a room. Water will enter into the room and damage things, it would be easier if were going to fix it before converting it.

About ten years ago I bought a ground floor flat. The rear of the property was road level on the first floor so to speak and my back bedroom wall was part of a basement. It was very damp when I bought it (got it cheap for this) Anyway I dried out the wall with heating and dehumidifier. I cleaned and painted it with bitumen paint then stuck rolls of bitumen on before erecting a stud wall.
I still rent it out and to date no problems. It was easy to do and cheap.