Hi fellas, I did a supply only job to a couple of builder pals £2000 worth of quickstep and they fitted onto a new concrete floor with fiberboard underlay, the subfloor had underfloor heating and it "looked" dry, 1 month on and the floor has bubbled all over, i asked if they tested for damp and they said no !! Question is :- they need new floor now, if this is fitted with barrier plus or timbermate as underlay will it be ok as both underlays have built in dpm`s, I myself always use barrier plus and never had a problem to date with moisture but wonna be sure before my builder mates throw another 2 grand at it.
Used barrier plus on a damp floor before and it is still O.K just made sure all joints were taped up well and taken up the wall
you cannot use fibre boards direct to concrete , should have put a dpm sheet down ist. i would either liquid dpm it to be safe or if thats not a cost option then sheet it ist then use barrier plus.builders eh stick to building and leave flooring to proper fitters.
Most (Probably all) the vapour barriers attached to underlays only cover up to 75% RH as far as I'm aware. The wording 'dpm' and 'vapour barrier' shouldn't be confused. I'm with the other lads, proper liquid moisture suppressor. Not a big fan of sheeting over high moisture content concrete tbh. The moisture can just sweat up and leave a nasty moldy smell..
I agree Trimmer. Damp proof is a very mis-leading term. The degree of damp being the main part of that. I've just downloaded the data sheet and they're using test values I'm not familiar with (Here's the link to grab the data sheet on page http://www.quick-step.com.au/Content/Underlay-details/QuietStep-Combi-Lay) . The test results state 1.7 g/m2/24hrs Anyone got a conversion table (Matt ). They're using ASTM international measuring standards, in particular ATSM E96 (http://www.astm.org/Standards/E96.htm). I'm not too clued up about inch pounds permeability...I'd like to be though for knowledge sake if anyone can shed some light??? Are they using pressure methods??
Apologies chaps...I've just realised I was reading the Australian QS site...Wakey Wakey :stupid Can't even find combi lay on the QS.co.uk site.. Still pretty sure they'll be a max damp tolerance though...Damp proof is like McDonalds saying they have 100% Beef in their burgers but as we all know there's probably only 20% meat in them From the wording a lot of people think they're actually eating burgers with 100% meat in them hahahaha
