Oven floor question

[happysnapper]

I have a 50mm layer of Calsil board and am about to lay my oven floor on top of it. Do I just lay the bricks directly onto the board or should I use a dry base of vermiculite, sand, a mix of both or should I make a paste out of mortar. I am worried about anything with moisture on the board as it lookslike it would soak up moisture quite easily

[downunderdave]

Yes it will. It will suck the moisture out of the mortar so fast that you won't be able to use it as a leveller. You can either coat the cal sol with something to prevent it, like vegetable oil painted on its surface first, or keep the mix dry which has the advantage of being able to remove floor bricks if necessary. I like to use a dry 50/50 mix of fine sand and powdered clay laid around 1/2" thick. The vertical joins will simply fill with ash.

[happysnapper]

Thanks Dave, I was fretting about the joints too so thats a good point re the ash. Tonights the night then...can't wait to finish bloody work 😀

[downunderdave]

Apr 19, 2017 11:41:46 GMT happysnapper said:

Thanks Dave, I was fretting about the joints too so thats a good point re the ash. Tonights the night then...can't wait to finish bloody work 😀

Unless the bricks are of an uneven thickness you can just sit them on the calsil which is a lot easier.

[dave36]

Apr 19, 2017 20:25:16 GMT downunderdave said:

Apr 19, 2017 11:41:46 GMT happysnapper said:

Thanks Dave, I was fretting about the joints too so thats a good point re the ash. Tonights the night then...can't wait to finish bloody work 😀

Unless the bricks are of an uneven thickness you can just sit them on the calsil which is a lot easier.

If it helps, that's what I did and it was nice and easy. The bricks in the centre and front  i ensured where spot on level (some of my bricks were a tiny bit bigger than others) and nearer the edges I cared a little less if ever so slightly uneven. 

It seems to have worked, I can run a peel over the floor without it catching on edges.

[daibaker]

What I did was cover my board in foil then added about 20mm of Castable (bought from kilnlinings) once this had hardened I had a nice solid flat base to lay my hearth floor.