Damp proofing and plasterboards

[boris.b.barnstable]

Hi there,

Our 1920's house has a 20' x 8' lean-to attached to it, (for want of a better description), that we use as a utility room and has a small bathroom in. It has a proper slate roof and the walls are standardish 9" thick. The issue is, it has no damp proof course, and whilst it doesn't suffer badly with damp at all, I am now set to redecorate and would like to do the job 'properly'.

The plaster will come off anyway, as it's old and not that good, and i have been looking at using something like 'Dryzone' which seems well recommended, and easy enough to do. However, then I was planning on attaching plaster board with the bonding agent, (Dab and stick or whatever the term is!) The Dryzone website mentions using an additive to a plaster mix if you plaster staraight on the wall, but can I get away with this dab and sticking the board?

OR, can I just appy 3 coats of the brush on bitumin/rubber type stuff and then plasterboard straight on to that. Would that be the cheapest way?

As you can tell, I need some good advice please!

Boris.b.barnstable

 

[Frederick]

Dryzone is an excellent product - definitely the best of the damp-proofing creams. However it will only stop damp rising up the wall and can't do anything about the salts that have risen into the wall over the years. It is these salts that the plastering additive is supposed to protect against. If you just replaster with a gypsum plaster the salts will react with the gypsum and make it crumble. However, you may be able to get away with dot and dab plasterboard as long as the bonding plaster is not gypsum-based. I would suggest that you call Safeguard (who make Dryzone) and ask.

 

[boris.b.barnstable]

Ok, thanks for the reply, sounds like the most 'professional' way to go.

I take it that the liquid bitumin/rubber coating is not seen as a 'proper' solution...

Cheers,
Boris