floorboards to replace 22mm chipboard

Why can't you use 18mm boards and put 4mm shims on the joists underneath them?

I've not found it hard to find suitable thickness timber for sale. You could even look at some pallets if you cba to sand, thickness* or carpet.

• with sanding belt not blades T&G:

1. blocks gaps / draughts
2. reduces differential warping
3. makes later access a pita
4. is not necessary

NT

Go to a timber merchant you are more likely to get decent dimensioned timber, Wickes, B&A et al have all really skimped on their sizes eg 2x1 PAR comes in at 44 X 18 whereas my local timber merchant can supply 46 X 21. Last lot of T&G I bought came at 18mm thickness so 4mm ply cut into 2" strips attached to the top of your joists should pack out the T&G up to your present floor level.

Richard

You need to find a better timber merchant. Such thicknesses and nominal

You have no chance of finding anything useful for this in sheds.

I've been back to the timber merchant and he suggested packing between the joists and the boards. I must admit, I had not thought of this!

I was wondering why you suggest thickness with a sander rather than a thicknesser?

Points 1 and 2 seem to be a good thing, and I use a multi tool to cut the t&g when removing for access, but I do wonder whether you are right with point 4 that just straight edged timber might be more useful!

I've gone back to the timber merchant and whereas the whitewood floorboards are too thin, they have some redwood boards about 21mm, so I think I'll use those.

I had a good timber merchant where I used to live. That house had the opposite problem that the boards were thinner than average. I think they were 16mm, which I assume was some imperial thickness (5/8?). Several times I wanted to use this as an excuse to buy a thicknesser but as they would do it for free, I new got to treat myself!

Now I've moved, I'm having to find timber merchants where I live now.

You're right that it's disappointing that Wickes don't have more of a selection but I phoned Travis Perkins and they were just as bad; I thought their "commercial" parent might have been better.

I meant use a sanding thicknesser rather than bladed type. You can hack one up using a frame & belt sander. Reused wood can contain broken nail/screw pieces etc that'll wreck your blades. Sanding belts are cheap.

It's certainly easier :)

NT

Because the joists are probably spaced 600 mm apart, so 22 mm chipboard is *necessary*. Using 18 mm chipboard is a dodgy builders bodge.

Quite how they got cracked is more curious. Maybe they didn't glue the tongues and grooves which they should have.

You can get 22mm 8*2 t&g caberfloor which I believe is plywood.

He ought to know better. Didn't he ask what the joist spacing is ?.

And even if you did, it would lose moisture and end up thinner than

I thought the OP was wanting to use timber* instead of chipboard, and the guidance for timber used to be 16mm centres up to 500mm and 19mm up to 600mm.

• from " I was hoping to use floorboards...The problem is that most floorboards seems to be 18mm...21mm boards but only as a pack of 5...I asked a timber merchant but the thickest the did was about 20mm"

I think it is chipboard.

Your point about why they failed is a good one.

My solution was to put strips of supporting Wickes studwork timber 38mm

• 63mm under all the joins (I used this size because it was the cheapest).

This protected me from a couple of chipboard laying beginner errors. 1) I didn't use enough PVA glue in the joins and 2) I didn't realize how hard you had to hammer the sheets together if you laid them on top of gap filling glue, so I didn't get them particularly tight at first.

Yep. I meant exactly that. It would have been clearer if I had said it.

I saw quarter inch ply used as a floor once. Like a bouncy castle!

NT

Yes, I am hoping to use floorboards not chipboard.

I'm not sure. It is in the entrance to the en suite and at the top of the stairs, so high traffic areas. It was like that when I moved in. The areas damaged are small. I think they have been cut and lifted to access plumbing and I wonder if it is because these small sections have not been adequately supported? These areas are not tongue and groove or glued.

I did wonder about doing something like this but then I thought since I would have to lift the carpet and the chipboard to get to the joists to attach these, I may as well replace the section once I have lifted it.