Damp proofing Garage Walls.

[AJCBSC]

We have a block built, free standing, garage rendered inside and out and are converting it into a office. What would be the best way of damp proofing the walls? We intend to use a plastic membrane on the concrete floor, under the battens, could this also be used on the walls, if not what is best?

Thanks in advance.

AJCBSC

[MustafaTickl]

You would be best off putting this question to the Technical Department of one of the specialist firms - Ruberoid, RIW, etc - and getting a complete solution from them. You have to consider floors, walls and roof/ceilings not only for incoming damp but for the very real problem of condensation. Solutions are required for ventilation, details of how to connect the waterproofing to doors, windows, around services etc, additional insulation to ceiling/roof etc etc.

[buildersmate]

I would consider using a product like this.
http://www.celotex.co.uk/walls/solid.php
Its designed to be an insulation layer and incorporates a vapour control barrier if you tape the joints between boards.
Walls don't get damp in themselves unless - there is no DPC about 15cm off the floor to stop dampness coming up from the floor, or the wall is subject to extreme exposure, or the roof is leaking.