liquid dpm and self levelling compound

[richel7]

I have laid laminate flooring in 2 adjoining rooms but in one of the rooms its a bit spongey in a few places, nothing major but slightly annoying..im thinking of lifting up floor and trying to make more level (i haven’t put skirting on yet so not to difficult to do).

Originally for the first room I used pva primer , wickes self levelling compound and then painted with wickes liquid dpm. Then laid down homebase underlay with built in vapour barrier and laminate and this floor seems fine

but for room 2 i just painted with dpm as was already tiled with old fashioned vinyl floor tiles and looked level and then laid underlay and laminate floor. This floor is a bit spongey in places though and i guess there are some hollows.

My questions are;

If i can get the underlay separated from the dpm (its a bit tacky) could i pva the dpm and use self levelling compound again (wickes website says not, but i have seen other sites that say it can be done, maybe using another brand of compound)?

Other than filling with more underlay, are there any other ways to level the floor ?

Any suggestions much appreciated

 

[mac391]

Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier.

i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene..

You also should have removed the vinyl tiles before priming and screeding.

If you can, remove underlay and vinyl tiles and as much adhesive as possible, then prime and screed, no dpm though..

 

[richel7]

Hi Mac, thanks for your reply...

i didnt make it clear but i didnt actually lay the self levelling compound on the tiles...where i self levelled i pulled the tiles up first. But when i pulled the tiles up they had been stuck down with a tar-like substance which was really wet underneath..its a 1960's house and a builder had previously told me there was no dpm in that room when he dug down in one area..

so i thought the liquid dpm was the best thing to use and painted everywhere that was going to have the lamiate flooring above it (including tiled areas, i didnt bother pulling them up where i wasnt levelling)...was this the right thing to do?

problem is i want to do some more levelling now and im not sure what the best thing is to use over the dpm to bond it to..i think its going to be quite difficult to remove the dpm..i painted three coats!

any more suggestions out there really appreciated

 

[mac391]

If i've got this right. You put dpm onto the black adhesive (usually bitumen) which in itself is a dpm. prolly a bad thing to do so leave it for a while to see what it does.

what you should have done is remove as much adhesive as poss then applied the primer (neoprene) not pva, then the screed.

You might be ok, just give it a little time to see if there is any reaction with your new dpm and the old adhesive, if not then screed over it.

 

[richel7]

so i should be ok to screed directly ontop of the liquid dpm if i prime it first with neoprene?

just 2 final questions..

is the neoprene i need the stopgap 131

and what mix would you recomend for the screed...3:1 sharp sand :cement?

many thanks for your help with this, ive searched the web but i couldnt find much info so your advise has been really useful
cheers

 

[mac391]

yes stopgap p131, you can also get neoprene from local tile stores..

Buy a bagged screed if you can, latex or water based, it's all pre measured for you. From f-ball, same people who make p131. www.f-ball.co.uk they have a list of suppliers you can buy it from. The wickes screed might be ok, just never used it myself..

Sand and cement is no good for a thin screed !! Again, your local tile supplier will prolly sell water based or latex screed..

good luck

 

[richel7]

thanks for your help, i will give it a go