best w/screw type for T&G floorboards to joists

[dave]

Anyone recommend a "good" wood screw for fixing 20mm T&G floorboards to joists? I have a room to do. I realize virtually any w/screw will kind of do but I'l like to do this job just once :-)

Shanked? Thread all the way up? I guess is best to pilot drill the boards but would like to avoid that due to the amount of drilling needed - if there a screw that allows it. If I use a shanked screw I guess I have to pilot the holes anyway.

I tried some 3.5 x 42 mm bugle-headed from Wicks and (without a pilot), screwing in near the bT&G end will usually split the board. The head diam. on these screws is too small anyway imo. Another thing I found that can happen, as the crew-head is rather a small diameter, the screw will travel too far into the board and the wood can close in over the top of it! Looks terrible and a pig to get out. However when they do go in properly they seem very firm. . Modern timber T&G seems soft compared to the original boards (1950's) which are much harder. So can get away without pilot holes in them I'll try and reuse some where possible.

Will use passivized screws.

[David]

I tend to use Turbo Gold from Screwfix. Something around 4.0 * 50. YMMV. On older boards, at least, they don't require a pilot hole. You do have to be careful not to drive them in too hard (depending on your driver). I use a Makita impact driver (lovely bit of kit) but all the torque control is in the trigger finger. If you have a screwdriver with variable torque you can probably be more precise.

HTH

Dave R

[Tim Watts]

I would use ScrewTite which are self drilling and have a plain shank. Very good experience of them.

or these:

Not tried these, but are similar to the screwtite and are made specifically for the job.

Or possibly:

which are star drive so easier to power drive and the heads won't cam out with removal and reapplication.

That's all assuming you are fixing "down" through the face.

There are also "tongue" screws with small conical lost heads for fixing through the edges - see links above, they are in a neighbouring section under "flooring screws". I think one is actually called tongue-tite

[Andrew Gabriel]

Thread all the way can prevent the board sitting in the joist. When the screw comes out the bottom of the board and pushes against the joist, it might turn once before biting, lifting the board up a little. You can avoid this by using shanked screws so there's no thread gripping the board when fully screwed home, or by applying sufficient pressure (e.g. standing) on the board that it can't rise up, or by screwing the screw in twice (unscrewing from the joist inbetween), so that second time it isn't trying to bit into the joist as that's already done.

You can get screws where the shank is undercut to the thread depth (although I just snapped one on the shank when screwing into a knot with a £5 B&Q electric screwdriver;-).

Is the board surface going to be the finished floor surface? If so, I think you will need to pilot/coountersink. In some cases, you might even want to plug the holes afterwards.

They may split later as the timber fully dries out.

Is there some reason you are screwing them, rather than nailing them?

[stuart noble]

I'd use lost head nails with a concave nail punch. Very neat

[Andy Burns]

Never used them, but ...

[Tim Watts]

Screws do three things:

a) No hammering on the floor which may be kinder to the ceiling below;

b) Less likely to work loose;

c) Easy to lift a board.

I much rather (and will) use screws.

[The Medway Handyman]

Decking screws.

[DerbyBorn]

I would always prefer to pilot drill to maximise the clamping effort.