Wet wall board expansion gap???

[rash_decision]

Hi guys, as per title, do you actually need an expansion gap with wet wall boards? I fitted some around a bath in a flat I own earlier today, and the only thing that I have since found out, that the salesman never mentioned, was to leave a 3mm expansion gap. I did my usual and measured size for size and they were neat between the bath and the ceiling, but I am now wondering if I should go by tomorrow and run a knife along the bottom to give the prescribed gap??

Boards are 1800 tall, and cut to 750 wide, one at each end of the bath, and two against the back wall. There is a 'gap' but they are neat............not the 3mm I am now reading about!

Any advice would be appreciated. Given I am gonna be filling/sealing the gaps with silicone sealant anyway, I am unsure if the gap is required??

Edited by rash_decision on Monday 16th January 08:05

[Andehh]

Who is the Manufacturer? I wouldn't take the Salesman as gospel, neither would I take the internet... Give the manufacturer a ring to be sure, water leaks arn't to be risked.

I am struggling to understand the need for a 3mm gap, unless that is to take up the potential movement of a full bath of water & prevent it crushing the wall....?

edit: At the end of the day 3mm isn't much, and silicone will happily fill the gap. I would leave 3mm, but fill it with silicone *before* applying the final silicone bead around the wall.

Edited by Andehh on Monday 16th January 11:10

[TA14]

Are you sure it's an expansion gap? (Could be though for water absorption.) Good practice is for the surfaces to be sealed to be parallel to each other, not perpendicular as is usually done, so a small gap would allow you to seal correctly. Doors and windows are made with these rebates.

[rash_decision]

Hi guys, thanks for the replies.

I was worrying unnecessarily last night, as I have since spoken to a guy I know who fits these panels regularly, and says not to worry about the way I have fitted them. The gap is indeed an expansion gap, but defo important in new builds given settlement and woods/materials changing characteristic.

The gap isn't to allow for sealing, but they will be well sealed with a good bead of silicone this evening.