Bouncy, creaking floors

[Rawdon51]

Hi,

We have had a second storey built onto our (former) bungalow. The second storey floor was constructed with joists well within limits specified by span tables, yet they are bouncy. On inspection, it appears that the builders did not place cross strutting at mid-points to the spans, and they will hopefully soon be remediating that.

However, the floors also seem to creak and "crack" excessively. The top layer is Egger (www.egger.co.uk) 18mm flooring board, which was laid before partition walls, with partition walls being constructed onto this base. Looking at the installation instructions for the flooring board (from here: http://www.egger.co.uk/co-uk-eng/egger-co-uk-products-flooring-boards_14741.htm ), the manufacturer recommends gluing t&g joints, and boards onto joists, before ring shank nailing. Our builders did not use ANY glue. They also used ring shank nails from a nail gun, but we know that some of these "failed" as we have successfully pulled up some of the boards from the joists without too much trouble. We have tried re-screwing these down - without glue - but the creaks and cracks are still apparent.

So I guess we're clear that the flooring hasn't been laid successfully. My question really relates to the "proper" way to fit it. Is all the glue stated by the manufacturer really necessary, bearing in mind the trouble it would cause if it ever needed to come up again. Also, is ring shank nailing the right way, or is screwing (have seen reference to some special Spax screws for this before?) the right way to go?

Thanks. Jon.

 

[Rawdon51]

Nobody any advice on this?

 

[kev23a]

I cant see the point of gluing the boards to the new joists,because they will inevitably shrink as they dry out.The method i have used over the last few years is.Lay the boards onto the joists with minimal fixings,just a couple of 8x50 screws in each board, and gluing the T&G joints with PVA or PUR .(obviously making sure that the boards are cramped up tightly).
leave for as long as possible before finally screwing the the boards down. This allows the joists to shrink. Then just before you lay your floor covering, tighten the screws again, its surprising how much they will pull in.

 

[freddiemercurystwin]

Once they've fitted the noggins, screw (not nail) the boards down at 200 centres, then, if you can be bothered, tighten them up periodically. All floors have bounce even concrete unless its about a foot thick and all timber floors creak unless you go overkill on the joist sizes/centres/fixings. Even then you often cannot stop the creaks.

 

[JohnD]

chipboard?

awful material for floors

18mm ply is far better. But yes, use screws, and retighten them after a few weeks of being walked on. Yes, it is surpising how much they will pull down.