First of all, is my terminology correct? These are brands of synthetic wood alternatives:
- #Wedi
- #Qboard
- #Schlüter #kerdiboard
etc.
Is “construction board” the generic name for this stuff? I think some people call them “building panels”. I ask because my search for Invidious (Youtube) vids came up short. I would rather not have a brand-dependent search query because I have to try many queries as it is to try to get this answer.
Qboard offers a factory made corner piece (called Qorner; attached to this post). I was trying to work out how I could do that myself. I’ve never worked with #constructionBoard, nor have I used a router, but I suspect they use a router to cut a “V” in the board without competely bottoming out (but nearly), so the outer skin does not get cut. Has anyone done this?
I’m building a small box in the shower which I will tile over. The box will cover a valve and must be semi-accessible. The valve will actually be controlled from the other side of the wall, so the box need not be opened routinely -- only if the fitting leaks or goes bad will access be needed.
I have an unlimited free supply of Ikea pressboard because neighbors throw it away daily. But I would not use it in a shower. Ikea pressboard is like a sponge with water. It’s also too thick. I have rigid space constraints. No limit on the box height, but the walls of the box must be thin (e.g. 10—15mm thick is what I have in mind). The construction board seems well suited for wet areas.
This is the old box, which was previously a solid block of concrete:
https://fedia.io/m/plumbing/t/58279/Advice-needed-exposed-water-valve-in-shower
My building style is to make everything accessible and servicable. So in that pic you see a floor tile around the box. That tile is actually removable. I went to great lengths to give a solid mating subfloor but without gluing it down. So if needed I can just remove the caulking around that tile and get under the showerpan. This is why the box walls must be thin. If the box is big enough to overlap the floor tile, then it would ruin the accessibility of the floor tile. Unless I somehow figure out how to make the entire box easily removable.. then it wouldn’t matter if it rested on the floor tile.
If it's going to be in the shower, I can't recommend MDF or even plywood. Probably better to go with solid wood if you can, or even better if you can access a 3D printer, use that.
Probably good advice, but I should note that I’ve been in several home improvement stores the past few days and they all have green particle board. One even had green plywood. I’ve seen how conventional particle board becomes like a sponge to water, so it’s a bit surprizing that they can treat it well enough to make it suitable for moist environments.
I told a salesman that although I would prefer a foam cement board Wedi type of thing, it’s too expensive. He then suggested the green particle board. It looks like they soaked the sawdust so that every spec of wood gets the water-resistent treatment before pressing it together. So perhaps it would be good for this.
I’m currently leaning toward using sticks of green (treated) solid wood for the frame, and ordinary drywall for the surface because I have this on hand. Then I would smother the whole thing in a liquid rubber of sorts. The particular liquid rubber I would use is most common in roofing but they advertize that tiles can be glued to it.
(edit) The liquid rubber brocure lists things it can be applied to.
“To be applied on bituminous foundations and on the most common construction materials such as concrete, stone, wood, steel, aluminium, cement plaster and polyester”
Hmm.. no mention of drywall. So perhaps I will need to make it entirely from wood before using the liquid rubber on it.
I don't have a lot of experience working in the wet part or a bathroom. I believe I saw a friend frame out a shower and then cover it with cement board once and then tile over it, so that may be an option, but take that advice with a grain of salt.