Screws for floor deck

[padstar]

I am due to start laying the deck on my ground floor joists. It's 22mm chipboard to be glued and screwed to the joists.

Am I correct in thinking 60mm long screws are correct for this?

If so are these the best <LINK> screws for the job? If not what are the best - I will need a couple of thousand of them.

 

[^woody^]

Just use some cheap, bulk buy, part threaded 4mm countersunk screws. Nothing fancy.

 

[Deleted member 174758]

As Woody says, just use low-cost bulk part threaded screws like these from Toolstation (at just under £25/1000):

50mm are enough for the job (x2 thickness). If you go to a screw supplier and order a few thousand you should get a better price that that

 

[RandomGrinch]

If so are these the best <LINK> screws for the job?

Just to add, although not needed for your current floor, I have used a few packs of the screws in the link.
...and as well as being expensive, they are also very good!

 

[padstar]

Thanks everyone. If there is no reason to use specialist screws to fix the deck then i will just stick with the forgefast screws from toolstation. I have used these throughout the build and found them to be a happy medium of being better than the cheap multipacks but still cheap enough. They do big tubs for £25 so i will get a few of these.

What is best 4.0x50mm or 4x60mm. Small difference in cost but if there is no benefit in the 0mm then i will save my arm on 10mm x several thousand screws.

I assume the fact it is being glued as well means the screws are not working as hard.

 

[Deleted member 174758]

Thanks everyone. If there is no reason to use specialist screws to fix the deck then i will just stick with the forgefast screws from toolstation. I have used these throughout the build and found them to be a happy medium of being better than the cheap multipacks but still cheap enough. They do big tubs for £25 so i will get a few of these.

As long as the Forge Fasts have an unthreaded section at the top of the shank (as in the example I posted above) and the screws will drive into the chipboard flush without the need to pilot and countersink then you'll be fine, otherwise you might find the sub-floor jacking itself off the joists as you screw it down.

What is best 4.0x50mm or 4x60mm. Small difference in cost but if there is no benefit in the 0mm then i will save my arm on 10mm x several thousand screws.

Ideally the the old "rule" used to be1/3 through the material and 2/3 in the joists, so 22 x 2 = 66mm (or 60mm, the nearest available size), however with glued floors you can go shorter, to 50mm without encountering problems.

I assume the fact it is being glued as well means the screws are not working as hard.

Yes and no (see previous para). You still need to pull the sub-floor down hard onto the joists so that the glue joint actually works, so your screws still need to be driven at 150mm centres.

 

[padstar]

These are the forgefast. Clear top and self drilling.

Are 4's ok or 5's better?

 

[Deleted member 174758]

4s will drive in flush with no splitting near sheet edges. You can struggle to sink 5s flush and they are more prone to splitting sheet material if driven close to the edges. Collated screws for flooring are often either 4s or 4.5s

 

[padstar]

Perfect thanks.

A different question but on the same topic. What sort of gap should be left to the perimeter 5mm? 10mm?

 

[Deleted member 174758]

10mm give or take. A 15 or 18mm skirting will cover that. Can alzo be sealed with compraband if you aren't installing skirting