Bathroom Walls 24” OC Tiling

[JHarbinson]

I’m doing a bathroom with tub surround. Tiling the surround and all bathroom walls. Studs are 24” OC. Width is only 61” so not enough width to use 3/4” kerdi board or 5/8” purple board. Worried about deflection on 1/2” hardi, etc. Was thinking to sheet in 1/2” CDX and then kerdi over that. Sound kosher or anyone have a better recommendation?

[cx]

Originally Posted by Justin

Width is only 61” so not enough width to use 3/4” kerdi board or 5/8” purple board.

'Fraid I don't understand that at all, Justin. Little clarification, please?

[JHarbinson]

Sorry about that! Width of bathroom is 61” stud face to stud face. Tub is 60” wide. I could bring the walls out thicker but afraid the tile will sit too proud of the tub rim. So I only have room for 1/2” board on the walls with studs at 24” OC. I’m concerned 1/2” rock or hardi will have too much deflection.

[jadnashua]

In searching through the HardieBacker FACTS, they say the maximum stud spacing is 16" OC, so you'd need to install some additional studs, which may be the best thing rather than cladding it with plywood then the board to keep the thickness down.

You might get by installing some cleats on the sides of the studs and install the plywood so it was flush with the stud edges, and you could probably use 3/4" stuff, and then the HardieBacker, but it still probably wouldn't be an approved installation.

[JHarbinson]

Ok, let me te-ask the question here as I think I may be making things too complicated. Walls are 24” oc. I see my choices as: 5/8” gyp bd with kerdi over or 3/4” kerdi board. What are your guys advice or is there another way?

[cx]

Originally Posted by Jim, Post #4

...they say the maximum stud spacing is 16" OC, so you'd need to install some additional studs,..

You can add some framing to comply with the requirements of the CBU manufacturers and the foam board manufacturers (I don't know what Schluter requires for their thicker board), or, if you don't want to comply with the manufacturers' requirements, you could use the thicker gypsum board and Kerdi as you suggest and take your chances.

It's all about risk tolerance.

My opinion; worth price charged.

[jadnashua]

Keep in mind that cement board isn't considered structural...it flexes which is why there's a maximum span listed for it.

On a wall, you might get by with less than they require, but slip and fall against it, all bets are off.