screws for cement board

[mike1979]

I use spax 25 mm but we aren't going to have a row over screws are we

 

[Spud]

I stopped a builder using dry wall screws once and asked him to screw down a floor with wood screws, I didn't specify which ones and went off for breakfast came back and found him putting in shanked wood screws he didn't take it that well when I asked him to change them for fully threaded screws doh !!!

 

[White Room]

I use spax 25 mm but we aren't going to have a row over screws are we

There good screws, I use them for the marmox washers....

 

[On one]

What size of turbo gold or spax would you use for hardie? I found that 3.5 mm x 25mm a too weak and don't pull board strong enough to the plywood, where is original hardie screws pull very tight

Maybe your driver/bit could be the problem. Recently I changed over to use an impact driver,but forgot it one day and asked to use a joiners 18v DeWalt cordless......with the right driver and the right bit it would pull the screws all the way thru the Hardie

 

[SJPurdy]

Hardie minimum screw specification for fixing to wood floors is:

No. 8 shank (4mm, I think) corrosion resistant screw with 9.5mm diameter counter sunk head. Length to penetrate substrate by 19mm ( or thickness of substrate if less).

 

[Sean Kelly]

OK let me add another screw to the mix:

http://www.toolstation.com/shop/Screws+Fixings//Reisser+Cutter+Screw+40+x+25mm/d/sd/p95628

£3.50 for 200 screws. They go in a dream with an impact driver (a must for Hardie).

IMO drywall screws are too thin to drive through concrete. I would imagine by the time it got through the other side it would look more like a nail!

 

[Mr Tiler]

I just tap with a hammer so it hold and once that goes down it is sold as a rock... don't forget also that the bed you are using to not have any voids is also giving the board a solid bed. I suppose this is an ''each to there own'' thread... and as widler says they manage to hold plasterboards on a ceiling why not on a timber floor?

 

[Stef]

Put another fixing into the mix, Clout nails!
States on Hardi guide that you can use them & I have used them in the past without a problem.

 

[widler]

The plasterboard gives when shear stress is applied where plywood and hardie don't ,under stress drywall screws snap very easily but if you wish to use them then go for it

I do 'go for it gary'
Ive used loads of screws , heads snap on most under stress .
Try it , screw one piece of ply down with drywall and normal wood screws, bet you can't get either up without extreme force.

Drywall screws are fine , we are plasterers as well ( you know bloody multi traders who know sod all 😉 ) so have loads at hand , why pay a fortune for more when they do just a good a job , which, they do

 

[Spud]

Wilder dry wall screws don't do as good as job but I really can't be bothered to argue about it and I always am prepared to respect someone's professional opinion even if I don't agree with it ,it not something I would ever use or recommend but if you are comfortable using them then good luck to you