floorboards to replace 22mm chipboard

[Stephen]

Hello,

The previous owner of my house had a loft conversion done and they used 22mm chipboard for flooring.

There are two places where the chipboard has cracked so I need to replace the broken chipboard. I was hoping to use floorboards. They are less bulky to carry and if I rewire or replumb in the future, they will be easier to lift too.

The problem is that most floorboards seems to be 18mm and I think the

4mm difference would be too much and be a trip hazard. The two damaged pieces are (1) at the top of the stairs and (2) the entrance to the en suite, so high traffic areas.

I se Wickes sells 21mm boards but only as a pack of 5 and I think they have to be ordered specially. I'm not sure if the 21mm is a nominal measurement and they might be less than this in real life.

I asked a timber merchant but the thickest the did was about 20mm, so I'm wondering what should I do. Should I buy 20mm boards; will the 2mm difference be noticeable or will the underlay take care of that?

Or am I restricting myself because I'm looking at T&G boards. Would I be better to get 1" timber and have it run through a thicknesser to make 22mm?

Thanks, Stephen.

[Pancho]

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

[tabbypurr]

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

[Tricky Dicky]

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

[Martin Brown]

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

1" floorboards are available for repairing older properties.

2mm level shift is within woodworking tolerances and unlikely to be a trip hazard - nothing that a rasp won't sort out anyway.

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

[Robin]

+1 - eg strips cut from 4mm ply

[Stephen]

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!

[Stephen]

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!

[Stephen]

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.

[tabbypurr]

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

[Andrew]

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.

[Andrew]

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

18 mm chipboard is only strong enough when the joists are no more than 18 inches apart.

[Andrew]

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

22mm anyway, unless you gave it time to dry out fully before using a planer/thicknesser

[Robin]

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"

[Pancho]

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.

[Pancho]

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

[tabbypurr]

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

NT

[Stephen]

Yes, I am hoping to use floorboards not chipboard.

[Stephen]

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.

[Stephen]

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.