How to layout Villaboard sheeting in bathroom?

Question

Good morning,

I am sheeting a timber framed ledge in our shower with villaboard before it is waterproofed and tiled and was just wondering what is the best way to run the sheeting on top of the frame in this corner to minimise issues with movement down the track.

Should I run the right hand piece all the way into the corner and then butt the left hand piece against it so no villaboard is crossing the corner intersection?

Or should I run the left hand piece all the way into the corner across the intersection, and then butt the right hand piece into it?

I’m thinking the first option is better as the two frames being fixed to two different walls may move at different rates. So if a piece is bridging the intersection it could buckle or warp and start causing waterproofing issues or grout/tile cracking. With no pieces crossing the intersection the tiler can run silicon at the corner joins to hopefully minimise movement issues.

What are your thoughts?

Nailbag · Answer

Morning @bigkid

I agree with @MitchellMc suggestion of getting both the tiler and waterproofer in at this stage for a quick look. I've always kept any trades I need as early into projects and have touched base along the way, even if it's just sending a photo text and a question. This is a perfect example.

I suspect the tiler is going to be more interested in dimension and any nooks for the tile type and size/s.

The waterproofer will be the one to worry about edge and seam joins as they will be the one to prepare them against any movement. That will be with the use of silicones, tapes etc. Personally, I would run the top sheets across any joins and go edge to edge to all walls.

My main recommendation is to check that your waterproofer is a "certified" one thats fully qualified and can profide workmanship warranty.

Nailbag

MitchellMc · Answer

Hi @bigkid,

This would be an excellent question to run by your waterproofer and tiler, and I'd suggest bringing them into the conversation at this point, as this isn't a standard fit-out.

Any time additional elements such as ledges, niches or custom framing are introduced, the professionals who will be waterproofing and tiling the area are often the best source of advice, as they'll ultimately be responsible for the finished system and signing off on their work.

You're certainly thinking about the right things, but I could only speculate as to which option would be best in your particular situation. If the timber framing is well connected, rigid and effectively acting as one structure, then you wouldn't normally expect significant movement at that corner. In that case, running the Villaboard across the junction could be advantageous.

However, if there is potential for movement due to timber shrinkage, settlement or differential movement between the adjoining walls, then it may be beneficial to decouple the tiled surface across that junction and incorporate a flexible caulked joint rather than relying on grout alone.

The reason I'd recommend consulting the waterproofer and tiler is that they may have a preferred method of construction that aligns with their waterproofing system and tiling approach.

Do note that regardless of where the sheet joint falls, it will need to be treated in accordance with the Villaboard installation requirements, including joint reinforcement and waterproofing tape as part of the waterproofing system.

The decision really comes down to whether movement is expected in that area. If the framing has been constructed correctly, there ideally shouldn't be any significant movement, but your installer will be best placed to assess that and advise on the most appropriate sheet layout.

Let me tag @Nailbag to see if he has any thoughts.

Please let me know if you have any questions.

Mitchell