Finally Got My Hands On A Couple Pieces Of Viva Board...

[attrayant]

...and I have to say I quite like it.

I was at my local building materials supplier picking up some things and noticed a pallet of viva board. I noticed a pile of scrap pieces next to it so I offered the shop keep a hundred baht to grab a few pieces.

In case you haven't heard about it, it's pressed cement and wood pulp. The wood pulp makes it lighter than cement board and easier to work with. Both my wood drill bits and wood cutting blades in my jig saw had no problem going through. Except for the weight, it really feels like I'm working with wood. It's supposed to be everything-proof (water, mold, termite, etc.)

For my first experiment, I cut one 16 mm plank in half and cross-braced it with two smaller pieces to make a platform for my articulating ladder:

This will help when I'm working up inside drop ceilings. No more trying to balance at the top of a rickety aluminum ladder. I stood on it (although no jumping up and down) and there was almost no discernible flexing of the boards. So I know it's good up to 90 kgs at least. I'm still looking for engineering specs to find out its exact ratings and tolerances.

It has the feel of a very dense hardwood, but as I said above it's heavy. Perhaps about 40% lighter than a cement board plank of equivalent size, so it is lighter but nowhere near as light as a stick of pine.

A standard 1.2×2.4×16 mm thick sheet costs 950B so it's quite expensive compared to plywood. I haven't bought cement board so I don't know how it compares to that in price.

Anyway I just wanted to share. Feel free to ask anything. I'm not sure what I'll do with the remaining pieces. But it's so easy to work with, I'm sure it'll come in handy to have lying around.

[wimpy]

I was looking at it at Global House, and I don't think it was nearly that expensive. I'll have to recheck the thickness. I was planning on using it for the walls in the shower area of my bathroom. Was going to silicone the seams and urethane everything. Think it will hold up to the moisture?

[attrayant]

It is supposed to be moisture-proof, although be aware that it does expand with moisture. The installation guide calls for a 3 mm gap between boards, and 5 mm or more if you use thinner ones (since they absorb moisture faster than thicker ones). They make a special rope and caulk that you're supposed to use to seal up the gaps. But it could be problematic if you put tile on it. In fact I just noticed on page nine of this document it says

Viva board can be tiled using a flexible tile adhesive. Avoid tiling over board joint.

That second sentence sounds like it could be a real pain. For a wet area like a shower or steam room, I'd probably go with cement board.

[wimpy]

I wasn't planning on tiling it. I have seen it urethaned and used flooring. I like the look of its' natural color.

[Pacificperson]

I was looking at it at Global House, and I don't think it was nearly that expensive. I'll have to recheck the thickness. I was planning on using it for the walls in the shower area of my bathroom. Was going to silicone the seams and urethane everything. Think it will hold up to the moisture?

I have not mixed silicone with urethane, but I know that silicone and fiberglass are a no no.