gap at top and bottom of wall for mastic

[leo_098]

Hi guiys what size of a gap do you need to leave for mastic top and bottom?

I have done 3mm same as the grout but have been told it needs to be 5mm is this correct?

 

[Del W]

2 or 3mm will be ok

 

[Ian]

Yeah 2/3mm for me, same as whatever spacer I'm using.

 

[Mike]

what's mastic? :lol::lol::lol:

 

[Stewart]

2-3 mil is fine then I normally use decorators caulk for the top and silicone for the bottom.