8x4 chipboard for flooring

[Ashworth1]

I have used 8x4 sheets of chipboard to start laying my flooring (stupidly).
The floor never felt completely solid and had noise/ and a
Spring feel to it.
A builder advised me to use t&g 8x2 sheets and glue/ secure with more fixings.
I now know it was stupid of me to use standard boards. Would you agree 8x2 t&g would give a solid job?
Thanks

 

[John D v2.0]

Are the joists solid and held by noggins? Are all the edges of the boards supported by joists or noggins and screwed properly?
Which areas in particular are springy? If the whole thing it must be a problem with your joists. Is it upstairs or down? What's the span and joist sizes?

 

[JohnD]

it sounds like you mean you used some kind of chipboard that was not flooring grade. Is that right?

Ply is much better than chipboard, which is a rubbish material fit only for the bonfire, and penny-pinching builders.

 

[John D v2.0]

Good point, I think the minimum thickness of chipboard is about 22ish mm for standard joist spacing.

 

[^woody^]

Joist spacing and noggin plays a significant part too

 

[Ashworth1]

The joists spacing is 400 mm. Length of joists are 3 meter. It's rattling and springy towards one side.
It was standard chipboard 18mm.
When I did it I didn't realise you needed a specific grade of chipboard.
The new stuff I was going to order is p5 t&g 18mm moisture resistant. Being that it's toung and grove do you think it will solve the issue? Thanks

 

[John D v2.0]

The new chip board will help but you still need to make sure all the edges are supported by joists or noggins.

 

[Ashworth1]

Thanks. So I take it the toung and grove will be stronger . I couldn't get away with cutting down the 8x4 sheets?

 

[JohnD]

if you glue the T&G, it strengthens the joints a bit. If not glued, and if not over a joist or nog, they will soon break.

But chipboard is very inclined to crack or break anyway, especially in traffic areas, or in front of the sink, or the bottom of the stairs. It usually stays sound until the builder's cheque has cleared.

I find chipboard hateful, and have spent a lot of time and effort patching it, before I realised it is better to rip it all up and lay ply.

All flooring should have the joints supported.

p.s.
If you've already bought chip, and don't mind doing it again in a few years, you could put lots and lots of nogs in to support it.
Personally I wouldn't, I'd use ply.

 

[tony1851]

Agree that chipboard is not the ne plus ultra of the building game, but 22mm t&g with glued joints, well screwed down and with all edges
supported is reasonably seviceable. Ply is better, but a lot more expensive.

 

[Ashworth1]

Thanks . It is for a bed room. If u go with ply would you suggest toung and grove of just standard ply sheets?

 

[John D v2.0]

I'm using standard square edge ply, it's about 10 pounds a square metre delivered (25 pounds a sheet each) so for a non master bedroom expect to pay around 100 pounds. Make sure it's 18mm thick and marked as structural ply, otherwise it won't be as strong. I'm using decent faced external board, but if it's hidden and upstairs you can get away with cheaper stuff if you can find it.

 

[JohnD]

I did my bedroom with hardwood-faced square edge sheets, Wickes had a good offer on them. You have to nog all unsupported edges (with large sheets there are not many) and I chose to stain and varnish it. Not everyone would bother. It is good enough to leave bare, with a few rugs.

I have used T&G Spruce ply flooring in the kitchen. It is a lower grade of ply and the surface is very poor, with dead and filled knots. That's why I chose the better grade later. I don't recall the comparative cost.

p.s.
I did try to work out the specifications of the ply, but the stuff I have seems stiffer than the old chipboard, and I am sure is stronger.

 

[John D v2.0]

yes just for reference the important bits for ground floor would be EN636-2, EN314-2 for moisture resistance, and first floor -1 would be fine for dry conditions. Also needs to be certified in a CE2+ structural factory. If you're bothered about external knots and imperfections go for a B facing rather than a C+ as it's much nicer.

 

[Ashworth1]

Thanks for all your advise.
Being that the floor will be carpeted would you advise;

Structural Softwood Plywood CE2+ 18x1220x2440mm or
Wickes P5 T&g Chipboard Flooring 18 x 600 x 2400mm

Obviously the ply is not t&g and wider - not sure if this causes more problems? But from the impression I'm getting chipboard only lasts a few years and then causes problems ?