Damp basement conversion advice: stud membrane required?

[iantresman]

Our Victorian brick basement is slightly damp, but no signs of liquid water.

1. Should I use a stud membrane like Oldroyd Cavity Drainage Membranes

2. Or could I just use, for example, 5mm WBP plywood with a large air-gap, and assume that the extra warmth will not cause condensation? Is it resistant against rot?

Regards,
Ian Tresman

 

[Static]

If you intend to use it as habitable it will need to be watertight, thus tanked. Which will be expensive

 

[Frederick]

I have used Oldroyd membranes for this application before and have to say they are very effective - in fact these types of membranes are used by most professional basement conversion companies.

Strictly speaking, you should have a sump and pump as part of the system as the relevant British Standard (BS8102) says that you have to assume that water will come to bear against the basement - even if it appears to be dry. However, as you are doing the job for yourself you are in a position to judge the risk for yourself. A decent sump and pump with alarm is likely to set you back well over £1000, so if you really think the basement is 'just damp' you could save a lot of money by not including one. On the other hand I have seen many 'just damp' basements become 'very wet' after periods of intense rainfall.