18mm Hardwood flooring

[Arthur 51]

Hi all. What would be the minimum thickness of plywood to be laid over the joists if using 18mm thick flooring (lengths 30cm - 120cm)

Thanks.

Arthur

[meow2222]

that makes no sense

[Arthur 51]

Plywood fixed to joists then flooring floats on plywood or fixed to plywood.. I am assuming that laying t and g flooring onto joists is not the correct method. Particularly as some lengths will be 300mm so won't span 2 joists.

Arthur

[Tim S]

Arthur 51 coughed up some electrons that declared:

Check the data sheet for your product - some of that flooring is capable of being laid direct on joists, depending on spacing.

Otherwise, 18mm ply will be bomb proof (10-15 quid (can't remember exactly) for a 2.4 x 1.2m sheet in B&Q, or 25 quid for WBP, but I expect you *might* get away with the next size down). As I said, have a look at specs for the flooring first (or ring the manufacturer).

HTH

Tim

[meow2222]

18mm chip is a sound floor all on its own, and you're putting 18mm of something already. So 12mm ply would be generous, and 12mm chip most likely sufficient. If anything's needed at all.

NT

[mark]

I think I would consider putting it direct onto the joists. Rather than put down plywood or chipboard wouldn't it work out cheaper just to discard the very short pieces? Or only use those short pieces when they bridge a joist.

mark

[Martin Bonner]

Assuming the flooring is T&G on all four edges (and joists at 16" centres), I think the answer is "zero". Obviously you need to make sure that a 300mm which doesn't lie over a joist is between two longer pieces - but you should be fine.

[Arthur 51]

Thank you, to all.

Arthur

[meow2222]

I think youre right, having seen a 12mm softwood floor work perfectly well

NT