Drywall screws into ceiling - 50mm or 60mm

[Simplez]

Well the ceilings have been dropped so they won't be overboarded - what size drywall screws should be sufficient just to attach the plasterboard into the floor joists.

Would 40,50, 60mm ?

I think 60mm would be overkill?

 

[denso13]

3 times the plasterboard thickness, roughly.

 

[Simplez]

3 times the plasterboard thickness, roughly.

12.5 x 3 = 37.5 plus 12.5 for the plasterboard so 50mm?

 

[footprints]

Unless you have any pipes or cables passing low down through the joist why not use 60mm, the joist will be at least 100mm even in a top floor celling.

 

[denso13]

12.5 x 3 = 37.5

Means 40mm screws. You really don't need anything longer.

 

[Barneyboyt007]

I have got to put 12.5 mm plasterboard up over 25 mm celotex what length screws should I be using?

 

[denso13]

I have got to put 12.5 mm plasterboard up over 25 mm celotex what length screws should I be using?

65mm would do.

 

[BlueLoo]

How thick is the board?

40mm is plenty

 

[denso13]

40mm is plenty

The board and celotex is nearly 40mm thick, how will a 40mm screw be enough?

 

[Deleted member 292770]

The board and celotex is nearly 40mm thick, how will a 40mm screw be enough?

.

 

[BlueLoo]

The board and celotex is nearly 40mm thick, how will a 40mm screw be enough?

Didn't see the celotex in the OP lol.