Floorboard questions

[geraldthehamster]

I'm about to start laying floorboards in an upstairs bedroom - 6 inch wide pitch pine T&G, about 20mm thick, resawn from beams, laid on 50mm wide joists at 400 centres (-ish). I have two questions, to which I hope someone will have answers:

1. When laying T&G, is it necessary for a butt join between the ends of two boards to be over a joist, or does the T&G render this inessential? I've seen conflicting advice.

1. How does one finish pitch pine (boards will be exposed)? I'd prefer to use matt varnish rather than oil, to save the future need to move furniture and recoat periodically, but the wood is quite resinous - is it OK to use varnish?

Cheers Richard

[Tim W]

geraldthehamster wibbled on Monday 19 October 2009 12:06

I'd join over a joist. You may need to lift that board in the future, cutting the toungue, so that could leave you up the creek.

[Donwill]

I would oil finish them, varnish might scratch and look manky in time.

Don

[Bruce]

In reply to question 2, I use OSMO products which are wax based, non-glossy and allow the wood to breathe a little. My own choice is a transparent finish that does not detract from the natural appearance of the wood, but colours are available:

[NT]

Clear varnish imho. Wear doesnt show, no maintennace, and floor safe ones are available. Oil requires reapplication wax is a maintenance nightmare, and traps muck Tinted varnishes look awful when they wear

NT

[Stuart Noble]

Preferably a solvent based varnish, and thinned to get it to penetrate. Wipe excess off with a rag, because any film it forms on top of the wood will probably be vulnerable.

[Cicero]

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I'd do the same; unsupported butted ends will almost certainly create a creaky spot.

Cic.

[geraldthehamster]

Thanks everyone, for your replies so far. I'll keep my cut ends over the joists, but it was worth asking the question.

I agree that oil finishes look better; but it's a matter of future maintenance and not having to move a huge bed every couple of years ;-)

As I described in a previous thread, on the "ordinary" pine boards already in situ in my hall, I achieved a compromise between not turning the wood orange, but having a matt finish, by applying one coat of water-based polyeurethane varnish, followed by several of matt, solvent-based polyeurethane. Applying the solvent-based directly would have turned the wood that orange colour that I was seeking to avoid.

I think possibly if I applied an oil-based varnish directly to my

*pitch* pine, which is already quite a dark colour, I might darken it too much; conversely, do we think that a water-based varnish would not play well on pitch pine?

I guess I need to do some test pieces, same as I did for downstairs.

Has anyone here used a varnish on pitch pine?

Cheers Richard

[PeterC]

Don't forget to leave them in the room for a few days to 'normalise' else they might change dimension slightly.

[rkm]

Oh yes, certainly. I aim to leave them up there for a couple of weeks. Even then I think they'll shrink noticeably after being laid (as do we all, of course), for thre reasons:

1. Pitch pine is resnous to start with
2. These boards have been in my garage fr 2 years
3. The atmosphere upstairs will be a lot drier and warmer once I've fitted the radiators and we've moved up there.

My cunning plan is to cramp the boards up and fix them with a sparse application of screws. If gaps have opened up after a year or so, I'll remove the screws, cramp the boards up again and fix them permanently with flooring brads. Nothing like advance planning.

Since my original post, I've also decided, after much googling, that I'm goingto experiment with not finishing the boards at all, except with rugs.

Cheers Richard

[Tim W]

[e-mail] wibbled on Monday 19 October 2009 22:06

Why not fix permanantly with screws? Unless you're using a nail gun, a power driver and the "right" screws (self drilling, self contersinking) will be just as fast, easy to remove to lift a board and probably have less risk of squeaking.

[geraldthehamster]

It's worth considering. Generally I think cut nail heads look "right" in floorboards, screw heads less so.

For a similar reason I'm not going to secret-nail the boards, as I think that would look a little modern.

Cheers Richard

[Cicero]

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Using cut nails (or any other manually hammered nails) will put a big strain on the ceiling below so unless it's in very good condition it might be wiser to go for one of the modern alternatives. I don't think screws look very good for a bare floor but there are several alternative types of nail which will look right and which can be used with a nail gun.

Cic.

[Stuart Noble]

The pitch pine I've experienced wouldn't take cut nails too well. It's too dense, and may split at the ends. Lost head nails are a good compromise, finished off with the correct sized concave nail punch (the flat headed ones are next to useless IME). I'd still pilot drill the ends of the boards though.

If the wood's going to shrink, fixings won't stop it, so I'd leave the boards laid loose for a few months before fixing.

Re the finish, pitch pine develops quite a respectable sheen with coarse wire wool. Not practical over a large area, but it illustrates the problem. I wouldn't give water based varnishes a hope in hell of sticking in the long term, but there are solvent based clear varnishes which would. IIRC it's an aliphatic urethane you need, rather than the usual aromatic type. A professional yacht varnish should be of that type, and IME you would almost certainly need to thin it at least 1:1 with solvent for a floor.

[george (dicegeorge)]

Perhaps because if you screw them in now and then they shrink a bit the new screw holes at the edges will have to be very close to the existing holes and so the screws wont hold, but you'll already have drilled countersunk holes so couldnt move the screws.

So perhaps use shorter smaller screws at first?

[g] PS I think maybe brass slotted screws might look good in floorboards.