I went to look at a job today that had quarry tiles over the majority of the floor. On the concrete part the Tramex showed from below 3 to 3.5 but the tile part showed from 3.5 to 5.5. I am looking to install Karndean. My proposal is Stopgap 200 (Acrylic) F75/76 then Stopgap 300. My problem is that in the info for the F76 it states that the sub floor must contain a structural damp proof membrane( I do know if there is one nor does the customer) but the F75 info does not make any mention of this - so is the F76 a definite no no and will a two coat F75 be ok. Thoughts and or experiences please.
All surface DPM's need a working damp proof. If the subfloor is old (20 years +) and you have reading like that then there is no DPM or its been bridged so cant use a surface dpm if you want a manufactures guaranty.
Oh great! That may be the correct answer Matt but it's not the one I wanted to get! (Could you try again? :smile: ) So plan B. The floor is not level so - level with Mapei latex trade or would acrylic be better? dpm with plastic sheet then Jumpax or similar lay Karndean. Or do I need a plan C?
Latex plan as Fball no longer recommend any compounds on subfloors with no dpm. (they no longer have a primer that is moister stable) Also Jumpax has to have a working dpm in the subfloor also. The plastic membrane you use with it is as a vapor barrier not to be used as a dpm. So cant use that either to 'Manufactories' instructions. British Standards are now to remove subfloors without DPM and replace to current Building regs. I know its not practical but thats the rules. All other trades follow rules like plumbers etc so why dont the flooring trade? if you install on that subfloor you are not installing to British Standards and your liable for the floorcovering and any damp etc you may introduce else where in the property by 'bridging' However, i have seen many floors installed as you suggest with no issues Just remember that you as a person has to offer the warranty as the manufactures ones will be void.
However, i have seen many floors installed as you suggest with no issues Just remember that you as a person has to offer the warranty as the manufactures ones will be void. I prefer to keep my hard earnt...
Surely if I use 1000 gauge visqueen under the jumpax that would be a working dpm as this is what is used under a concrete base for building regs. anyway. If I had to resort to plan C which would be replacing the sub floor (not something I think he would do) how far down would it need to go?
The problem with the sheet being used as a dpm is it is free floating and not held down by a few tonne of concrete. Also the edges should meet the DPC course which you can do also but as floating will move around and leave the DPC. Then any moister will start to build up more as water than vapour which will raise humidity and start to effect the jumpax product. :cry: (things like teh water table etc will make the difference here. ) As for subfloor depth, it will depend on building regs. Im not 100% sure but i believe that all new subfloors are supposed to have a insulation now at minimum 75mm then a 75mm fibre bonded screed over the top. I would get a builder to come in and quote for what is needed. I did a thread some where on here of my floors being relaid due to teh above quarry issues.
As for subfloor depth, it will depend on building regs. Im not 100% sure but i believe that all new subfloors are supposed to have a insulation now at minimum 75mm then a 75mm fibre bonded screed over the top. Is that not only for new build rather than refurb??
refurbs seem to have different laws/suggestions to newbuilds and different areas/councils differ too. As I found out once
