Insulated tile backer board to combat damp wall

[mrbenn101]

Hi,

We put a waterproof membrane 1.2m up a damp wall, however the damp is creeping above this, I suspect coming through the plasterboard through the dot and dab mix, which seems to attract water. In an attempt to solve this as easily and permanently as possible, I was thinking of using an insulated tile backer board from CTD, stuck to the existing (slightly damp in spots) wall with Intumescent acrylic sealant from Everbuild, then using a sealing strip like you'd use in a wet room, to totally waterproof the wall. I was then thinking of skimming directly onto this surface.

Do we reckon this might work OK? Slightly expensive as I need 5 tilebacker boards at 12+vat each, plus a couple of tubes of sealant, and then the waterproofing tape, which I have already. Any downsides to this anyone can think of? Will the plaster take to the boards, so long as I prime it, PVA or Acryllic primer?

Sean.

 

[mrbenn101]

Just to add to this, the wall in question is an internal wall, in a 200 year old cottage, the other side is battened and plasterboarded, and similarly protected with a membrane, but no damp spots ( I suspect due to the lack of dot and dab)

There is a chemical damp proof course newly installed on the wall, which seems to have been a complete waste of money. I wish I'd have just bitten the bullet, and got the grinder out and installed a slate damp, but it's a join I don't fancy now.

 

[Nekkid]

Hello mr benn.
Im afraid i cant comment on the poducts you are considering as im not familiar with them, but i can see a downside. The damp will come out somewhere. If you trap it in the wall all the way to the cieling, it will eventually come out in the cieling instead.
Can you explain what you mean by chemical damp course?
Im really only familiar with timber buildings, but damp is damp, and it will always find a way out!
Charley

 

[mrbenn101]

Hi, Thanks for your replies. I'm thinking the same, but also thinking I might as well put a physical damp proof course in, either slate or plastic or both. By chemical damp I mean't an injected damp proof course.