Any wooden flooring experts here?

[gasman]

Morning everyone
I have 30m2 of herringbone wooden floor to lay. It is engineered oak 120 x 600mm prefinished. Its going onto a concrete substrate which has had the old parquet flooring removed and been self-levelled. I'm pretty sure there is no DPM in the floor (Victorian house) but there were no signs of damp in the old parquet flooring. I have watched quite a few YouTube videos and it seems fairly straightforward, if a little fiddly. I was recommended to glue it down rather than have it floating. Is that sensible?
I was thinking (and have been advised) to put in a liquid DPM before the floor goes down. Any recommendations? I was recommended FBall F77 or Ardex 1C which are both 2-pack epoxy - but the F77 data sheet says it needs priming before the adhesive is applied which seems like a lot of faff. Otherwise I have used BlackJack paint before but that never really goes off and that room is the only way in or out of the house so that won't work very well when it comes to laying the floor if it is tacky.
Any experts out there with some sensible advice?
Many thanks all
Cheers Mark

 

[AJB Temple]

I am not an expert, but I have repaired a herringbone floor. My first flat in London was ground floor and had parquet throughout. The building was old and there would have been no dpm in the floor. However, the parquet was all laid onto what I believe was hot tar, which would, I imagine, have acted as a dpm. If your floor was laid in this way, then you might consider replacing the dpm.

You can check if damp is coming up though the floor by laying something such as a rubber mat on a small area for a couple of days and see if a damp shadow or even a wet patch appears.

 

[gasman]

Thanks for your reply - in fact the company which supplied the flooring and glue have said the glue will act as a DPM as well - similar kind of concept I imagine

 

[Jake]

The primer is easy enough, it's just a pour on the floor and brush it around - work of minutes.

Ask the flooring shop if they are warranting that advice...

 

[Jake]

But usually the primer/liquid dpm would go under the self-leveller not over it.

F Ball tech advice are helpful on the phone, haven't tried Ardex but would imagine the same.

 

[MusicMan]

I had my wooden floors done professionally. The base was a concrete raft, probably with a DPM. They put a further DPM (thick polythene sheet) down, then interlocking chipboard, then the floor (reclaimed teak about 3" wide T&G) both nailed and glued but not glued all over. It looks as perfect as when it was done 17 years ago.

OTOH I used a self-levelling DP mixture on a concrete shed floor then put chipboard down. Damp has got through and there is now a lot of mould.

My learning experience is not to skimp on DPMs!

 

[Terry - Somerset]

I know nothing about DPM but the killer point seems to be about risk avoidance:

- do DPM properly and have a (say) 90% chance of floor lasting (say) 15+ years
- short cut and have a (say) 30% chance of having to redo the job in <5 years

If putting in or painting DPM was < a days work and < £100, then the answer should be clear. Were it 3 days work and £500 you may come to a different answer!