Shower surround substrate

[Waluigi]

Ok, when you say cement board, generally people think you’re talking about Hardiebacker or Aquapanel etc. A foam board or XPS board is a lightweight foam board with cement coating on both sides, like Wedi, Marmox, Dukka etc.

Foam boards generally require more studs than the likes of the true rigid cement boards, especially when you’re dealing with boards that tend to be 600mm wide. Unless you increase the thickness of the board. For example a 12mm Wedi Board usually requires vertical studs @ 300mm centres whereas a 20mm Wedi Board will be fine with 600mm studs.

 

[STEvieXE]

Ah so it needs more vertical studs for screws at smaller centres!

 

[STEvieXE]

Update! After the joiner not ringing me all week as promised to board my wall I threw the head up this morning, took s half day from work and went and bought wall hardie backer, tape and screws! Finally got the plasterboard down and new hardie backer up.

As it will be tanked what way does that work in conjunction with the Hardiebacker tape and adhesive over the joints?

So I need to get the tiles to tape and skim the joints and then come back to tank over the top?

 

[STEvieXE]

 

[Waluigi]

Two choices- tape the joints with alkaline resistant tape and tile adhesive, tank the next day. Or tape and tank the joints with your tanking membrane.

Prime beforehand whatever you do.

 

[STEvieXE]

Can the tanking take the place of the Hardie tape and adhesive?

Ie skip that stage?

What is my best way forward with this? The 2 stages combined?

 

[Waluigi]

For me personally I’d use the alkaline tape and tile adhesive. This adds a bit more strength as there are no noggins placed horizontally between your HB boards.

I’d Really push the adhesive in too.

Then I’d probably just run my tanking tape in the internal corner abutment.

Up to you whether you tape and tank the HB joints too. Be wary of ridging

 

[STEvieXE]

So the joints would be done to Hardie instructions and the just the tank painted over.

The tanking tape would only be used in the corners edges?

What is ridging? (Sorry!!)

 

[Waluigi]

Yes that’s correct. Ridging being a ridge built up on the joints if you tape them and then tank and tape them. For example, mosaics wouldn’t look great on that wall as you’d see a ridge!

 

[STEvieXE]

Ah I understand now!I think ill go with the tape n addy the Hardie joints n tank over but no tape and tape the edges!

Thanks for your help, it is really appreaciated