To tank or not to tank STS board - Tile Advice

[burg93]

Hi all, probably a pretty common question but I'm going around in circles looking online for a proper answer. I'm going to be fitting some tile backer boards to a 2 wall shower enclosure soon and decided on the STS boards as they seem cheap and decent enough.

The STS technical guide just says to use their adhesive on the joists before using their washer kit to secure the boards which is fairly standard, it then goes on to say use the adhesive between boards which will waterproof seal them and eliminate the need to tape the joints. It then says you're ready to tile straight onto the boards as-is.

STS also have a video on youtube stating that if the boards are used in a shower you must tank them too... Now I don't mind doing it, the mapai kit is only fifty quid but wanted to make sure this isn't taking it over the top... In their guide do they mean you can tile straight on without tanking if you're using it on a non shower wall?

Just looking for some advice from someone who does this day in day out! Thanks.

 

[bsc ceramics]

Tank It.... belt and braces.
codes of practice say all intermediate wet areas should be tanked

 

[Slippery]

£50 is a lot cheaper than a potential fail, As bsc said, belt and braces, can't fail wont fail!

 

[burg93]

Cheers both. Will tank away in that case!

 

[Ben-gee]

Excellent advice from the lads, for £50 just do it - there is no “over the top” when it comes to preparation!!
Sounds like you’re making a good job of it, well done.