Hi guys I've got a job to price which has some ATA residue on the floor. I'd normally use NA but are there any alternatives? Cheers
Nothing really. NA can be used due to low strength so moves around on it. But dont forget you can only use NA under domestic loose lay vinyl.
Thanks Matt. A bit more help / advice if you could. I've got a job to price. Pipe went under the concrete. Old flooring taken up by CR, kitchen screeded over (ontop of ATA), vinyl laid. Called to look at by insurance company. Vinyl bubbled, pulled part back, visible damp patches on floor and discolourartion on back of vinyl. Tramex reading 5% moisture in slab. They want a liquid DPM laid, rescreeded and new vinyl. Can I go over with NA, then DPM 1c, screed again then fit vinyl or should I scabble / grind the bitumen adhesive off first?
you can go over as suggested yes. But you are relying on the strength of the bond of other products. For instance- the NA will stick to the bitumen but if the bitumen comes away from the subfloor you are going to be at blame. The NA has done its job and stuck at the end of the day. When you add a dpm you will increase the pressure on teh subfloor glue so remember that also. I would also presume as this is a old a subfloor then it is rising damp and not residual moister from the concrete drying out. If thats ths case then you cant install a surface dpm. Some manufactures will say you can as the DPM itself wont fail. What ever the dpm is glued to will fail so again not a manufactures issue. If this subfloor is subject to rising damp and the customer wont dig the floor up and replace to British Standards then i would use a latex compound like NA and then install isolator membrane. Problem solved. EDIT- just re-read that a pipe had burst. In that case then you can use surface DPM. The subfloor should be allowed to dry out really. Either way the old adhesives should be removed and started with fresh base and dpm applied to that.
I thought you couldnt use dpms over bitumen? I know people that have, but then I know people that have stuck every amtico job to ardex na and not had any problems with it???
Correct mate or should i say we would never recommend it. Some manufactures will say you can as its not the dpm that fails but the product underneath that is nothing to do with them. I know loads of people who have been sticking to NA and similar products also. Me being one of them years ago until i started getting complaints and found out that the complaint was down to the latex not being up to the job. Basically your main complaint with sticking lvt etc to weak compounds is that they dent easy. Its not the karndean etc that is denting but the compound underneath. Hence we should be using a high strength compound under vinyl / lino / lvt etc that is glued down. NA etc is fine with domestic loose lay stuff. Obviously we would not be loose laying vinyls etc in commercial areas hence its not sutible. Its got nothing to do with the bond strength if thats what you was thinking
Ok, that makes sense. Does that denting happen on domestic jobs then or mainly commercial. What sort of thing can cause it?
Denting can be stiletto heels, people dropping stuff etc. On a domestic job its fine under vinyl as the vinyl is normally a loose lay cushion back. Simple hole gets put in the vinyl if you abuse it.
