Hi, I’ve had 120m engineered wood layed across ground floor, part is new extension, part existing flooring. The main area is existing sub floor, which was previous original wooden flooring, and screed elsewhere (new parts). UFH is in the screed and is in pre routed insulation board over original floor. UFH is run by an air source pump so water temp only 30 max. There were a couple of areas not finished great due to levelling issues between screed and original, so flooring company returned to sort, lifted floor and found water. There are no pipes towards the rear and the UFH has stayed under pressure, it’s a closed loop. There is a dpm membrane over the block and beam floor subfloor that the screed was poured over. Water appears to be in several places with damp paper and polythene underlay - we’ve lifted half the floor and can see it’s only in screeded areas where there seems to be anything. Seems obvious it’s damp coming up from screed. When we started lifting the floor the contractor took more damp readings and while inconsistent, they were super high in different sections, and in one section of screed a divot has appeared. I believe it’s around 50mm of screed. Back in early Feb Flooring contractor took damp readings and were happy to go ahead, I’d say screed was laid early December and flooring mid Feb. There’s a blueish dpm of sorts been painted over the screed by the flooring contractor. Is there anything I should be considering?
Find out what Dpm was used if you can. Blue could be Fball F78 or maybe ardex MVS 95. I’d of gone a epoxy Dpm though or uzin PE404
It was under pressure for about 2 months, but the heat was only engaged after the floor was installed, it’s limited to 30 degrees though at pipe level so hard to see that impacting…
Well you’ve got a building site and a screed full of moisture and the first time the heating goes on it will always push moisture out. We wont fit anything over ufh until the heating has been run for two weeks. What did the flooring contractor use to take moisture readings ?
Makes sense, they used a twin pronged hydrometer of some kind. I’m wondering if condensation is always there in these circumstances , but there’s rarely a need to lift, so no one sees…then maybe in my case a lot of the condensation moved as they raised the floor, it’s a Kahns underlay that’s basically a polythene bag. I’ve a meeting on Friday to talk options, but I’ve said it must dry out. I have dehumidifier going, but it’s hardly interested. Cheers for your help btw. Appreciate it.
