Length of screw

[Derbyboy]

1. What length should I have for chipboard/plywood screws when installing 15mm construction plywood on 70-studs in a bathroom?

2. What length should I have for the drywall screws for the drywall that is outside the construction plywood in the bathroom?

3. What length should I have for chipboard/plywood screws when installing 12mm construction plywood on 70-studs in a kitchen?

 

[Hästängsudd]

1. What length should I have for chipboard/plywood screws when installing 15mm construction plywood on 70-studs in a bathroom?

2. What length should I have for drywall screws for the drywall that is outside the construction plywood in the bathroom?

3. What length should I have for chipboard/plywood screws when installing 12mm construction plywood on 70-studs in a kitchen?

1. 30-32mm
2. 42-45mm
3. 30-32mm

 

[Derbyboy]

Thank you so much!

bonus question:

gypsum on raw wood panel 17mm can I use 30mm gypsum screws or do I have to go down to 25mm?

 

[Hästängsudd]

Thank you so much!

bonus question:

plasterboard on raw wood 17mm can I use 30mm plaster screws or do I need to go down to 25mm?

What's behind the raw wood?

 

[Derbyboy]

Isolation

 

[Hästängsudd]

Insulation

Then it doesn't matter.