Ply subfloor questions

[Neber]

Ok you might have noticed a couple of earlier posts but things have changed so I have a few more questions! I have just ripped up my entire chipboard subfloor as it had more waves than the sea (18mm drop over <1m, must have been like this when built as it's only an 18 year old house, big developers!). I'm raising the joists with ply strips ready to attach 18mm ply, then secret nail 18mm solid plank flooring.

Please could someone help with the following questions:

1. Do I need to let the 18mm wbp ply (above crawl space) acclimatise. I plan to lay the oak floor one week later?

2. Wood moisture sensors seem to be about £300 is it possible to hire or buy a cheap one or should I not bother?

3. Is it better to screw and glue the ply to the joists rather than ring shank nail?

4. As a moisture retarder, it is recommended to lay 15# builders felt (tarpaper) between the sub and solid floor, what is this is it the following:

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=31795&ts=02122

Any answered questions would be much appreciated

 

[DAZB]

Hi , the ply shouldn't need to acclimatise because it is a composite sheet and not true wood and therefore won't alter a great deal in the setting you have planned. I wouldn't waste your money on the moisture tester either personally and yes it would be better to screw than nail. The paper you want is just called building paper as I know it and most good builders merchants should have it. It is a fairly robust brown paper which has a tar based membrane combined in it.

 

[Neber]

Thanks for the advice Dazb, went to B and Q today to see if I could find any tarpaper or laminated resin paper and I'm still a bit confused they had lots building felt for roofing (one rapidseal underlayer was about 3mm thick with film one side and thick tar the other, but this seems too thick and messy for a floor) they also have DPM sheets for under laminate. Couldn't find any building paper.

What should I use? Any one know a product name I can pick up from screwfix, homebase, B & Q, focus or Buildbase (as they are all within a mile)

 

[Jasonb]

Buildbase would be the only one worth trying, as Dazb said a "good builders merchant" will have it noyt a DIY shed

Jason