Preparation of floor for cork tiles

[Avocet]

Hi All. A question from a Newbie, if I may!

I want to replace our landing carpet with cork tiles. The house is about 15 years old and the existing floor is made of 8' x 4' T&G chipboard "?Weyroc?" sheets. We've recently had an extension built and want to continue the floor through the landing and into there but there is a very small amount of movement of the Weyroc sheets in the extension where they butt up against the original ones on the landing. To cure this, I was going to cover the whole area in 6mm standard ply but I have a couple of questions:

1. The ply has warped since I bought it. I've had it stacked on the floor for a few weeks and each sheet is a bit bent and / or wavy. I've tried standing the sheets on their edges and turning them over. They gradually seem to be going back flat (ish) again but not completely. I was thinking of nailing them at frequent intervals to the chipboard. Would every 300mm or so seem appropriate?

2. I guess I ought to use round-headed nails so that they don't pull through the 6mm plywood. Perhaps ring-shank nails would be a good idea too? I was going to use nails about 25mm long so that they don't poke through the far side of the chipboard and do anything nasty to central heating pipes. What gauge of nails should I be using?

3. I was thinking of buying (or hiring) a nail gun as there will be a great many nails to put in. I'm worried that hammering them in conventionally will damage the plasterboard of the ceiling beneath. Is this likely to happen?

4. If I go for a nail gun, I'll obviously need one that can fire round-headed nails. Can anyone recommend one and a source of nails? Ideally as cheap as possible! I don't imagine it will be getting a great deal of use after this project! I've been looking on the Screwfix / Machine Mart / Northern Tool websites but all the cheaper ones seem to only fire the sort of nail that consists of a stamped piece of flat metal with a slightly "L-shaped" head. These look like they might pull through the plywood after a while. All the ones that say they can fire round-headed nails don't seem to be able to use nails as short as 25mm.

Thanks in anticipation!

 

[mattysupra]

you still need info on this?

 

[Avocet]

All info gratefully received!

From what I've been told so far, I'm in cloud cuckoo land looking for a nail gun that will fire 25mm ring-shank round headed nails for the sort of money I'd be willing to spend on a one-off job! I gather they're about £300-£400!

Other than that, I'm still worried about the warping of the plywood sheets I've bought, but a few people have told me that they all do that, and that it won't be a problem if I nail them down at 300mm squares. Quite a few people have told me to screw it down. Nobody has yet suggested that I ought to glue it though.

 

[mattysupra]

first of all they need to be pinned at 150mm centers and 100mm around the edges and about 10mm from the edge/joint. You can use ring shank 22mm nails or screws or divergent staples. The nail gun you need is made by spot nails and i think the code is 606? It will fire 22mm divergent staples.

These warped boards, is the plywood WBP/exterior grade? It should be. They always warp a little, maybe a picture might help so we can see how warped they are!

P.s, dont glue them down

 

[Avocet]

Thanks for that. Yes they're WPB "Standard ply". The amount of distortion varies but if I take the worst one and lie it flat on the floor, the centre of the 4' edge is about 4" above the floor whilst at the opposite end, the corners are about 3" off the floor. Obviously if I stand on it I can force it flat. The rest of them vary. Some of them are fairly flat, some have the odd corner poking up or a bit of a wobble along the length of the longer sides. I've had them in the room that I'm going to be flooring for about 4 weeks now and have tried stacking them flat and standing them on their edges. If I do the latter, they seem to develop a big bend in the middle - which flattens out when I stack them flat for a few days. I'll try to take some photos later.

I've got a bag of 22mm ring shank nails that have a 2mm diameter shank and the heads are about 5mm in diameter. Would they do?

Thanks for the nailer recommendation. To be honest, that's going to be too pricey for this one job. I think I'll just have to not be so lazy and use a good old fashioned hammer, I think!

 

[mattysupra]

need a picture of your plywood. And yes you have the correct ring shank nails. Make sure you pin at the correct centers.

 

[Avocet]

Still haven't managed to find the camera! Anyway, curiosity got the better of me and I tried nailing down one of the sheets in the way you suggested. It was brilliant! The nails hold it down a treat - nice and flat. I think I'll probably just press on now to be honest. Thanks again!