85mm drywall screws needed

[Bucks]

Does anyone know where I can get 85mm drywall screws, I am dry-lining a wall, 12.5mm Gyproc, 50mm Kingspan, 25mm battens fixed to brick wall, don't seem to be able to find any 85mm anywhere on the net, they all seem to jump from 75mm to 100mm.
If 85mm drywall are not available will normal woodworking screws be OK.

 

[Chukka63]

just use normal screws.

 

[Richard C]

If 85mm drywall are not available will normal woodworking screws be OK.

As long as they are zink plated; don't know for sure but I've also got a feeling that the black phospate coating on drywall screws is less likely to react than zink with Gypsum plaster on the heads; possibly one of the reasons (apart from movement) why the heads pop off older ceiligns fixed with zink plated nails.

 

[Chukka63]

i tried to get long drywall screws and couldnt so used normal spax.what can you do when things arent readily available if at all.Building control should make sure products are in supply before asking for stupid amounts of insulation in this kind of scenario.

 

[PrenticeBoyofDerry]

have you thought about increasing the section on the timbers?
I'm sure they do a 90mm drywall screw!

 

[neds]

I've used regular zinc coated screws when I have been stuck before. Plastered over and no rust bleed through yet!

 

[Bucks]

have you thought about increasing the section on the timbers?
I'm sure they do a 90mm drywall screw!

Good idea, but in this situation I want to keep the room as wide as possible, so I don't want to increase the size of the timbers.

Edit: Everywhere I looked drywall screws jumped from 75mm to 100mm.

 

[Bucks]

THANKS for you replies guys,

Best screws I have managed to find are the Timberdeck 4.0 x 85mm decking screws from Screwfix.
I have just purchased a sample box & they seem ideal not much thicker that a proper drywall screw, I just hope the coating on them will be OK with the plaster.