Floor prep and door reveal

[bsr]

Hello

I've done several floating floors; this will be my first glue down. 36m2 of engineered wide plank maple, T&G all four sides. I have three questions if I may:

Firstly, picture 1 shows some effluorescence in the door reveal. Previously there was a small damp patch on the screed. This was minor but longstanding, the carpet gripper had gone black. I called back the fitters (under warranty). They siliconed inside and out. It seems to have dried out. Should I do anything here? I was thinking whether it is worth a liquid DPM in this area (I think not because any damp would probably come under the door frame rather than through the screed). Should I fit a single plank strip along the door reveal at right angles to the rest of the flooring? That way it could be sacrificial if the damp came back.

Secondly you can see a crack in the screed with signs of previous repair. What do you suggest I do here? I will self-level over the top but it may well crack again. The join is at least 30 years old so do I assume all settlement has now happened and the gap should be stable? Otherwise I could put some plastering fibreglass mesh across the joint to reinforce it, and self-level over it? I've heard about resin repairs but never done one. Would that be OTT?

Finally, any tips on levelling a 6m wide room? I don't have a straight edge anything like long enough!

Thanks very much

bsr

 

[bsr]

No one?

 

[Deleted member 174758]

I was thinking whether it is worth a liquid DPM in this area (I think not because any damp would probably come under the door frame rather than through the screed).

My experience of working with floorers on commercial jobs is that if there is even the remotest chance of moisture they'll routinely put down a liquid DPM. In the absence of being able to test the floor with something like a Tramex concrete meter it's better safe than sorry

Secondly you can see a crack in the screed with signs of previous repair..... I could put some plastering fibreglass mesh across the joint to reinforce it, and self-level over it...

AFAIK the proper way is to dig out the crack (to about 20 or 30mm width) using an angle grinder and following-up with a breaker, Vacuum-out, fill the resulting gap with a 2-pack epoxy cement mix and press a fibreglass mesh (but without adhesive on it like scrim) into the resin whilst it's still wet. That will tie the two halves of the floor together. You can get fibres to add to the mix for a stronger bond, but it's probably overkill in this case. The adhesive on scrim might react with the epoxy and I'd avoid it for that reason. SLC has no inherent strength and if you try using that it might well crack if there's any further movement in the floor

Finally, any tips on levelling a 6m wide room? I don't have a straight edge anything like long enough!

6ft feather edge used in overlapping strokes.

 

[dazlight]

Deco needs a liquid dpm. Any loose screed needs taking out and filling in. Floor needs to be solid.

 

[bsr]

Thanks. Have dug out the loose bits and widened the cracks. Will repair with epoxy mortar from Toolstation.