Michelle 42" oven question

[That's Amore]

I think the sand is just fine. As far as the outer edge is concerned, some choose to mortar them to the floor and others choose just to mortar them to each other. I chose to mortar them together as they sat on the fb board and so it would be useless to mortar them to the floor.

Cheers,

[SteveP]

There is no need to mortar the floor bricks; the floor is basically free floating. The FB board shoud be level and you shuldn't have to use sand/fire clay as a leveling agent. I left about a 1/8" gap between the floor bricks and soldiers to allow for floor expansion. After a few fires, you will have enough ash to fill in the cracks between the brick joints.

[gdest]

Sand is used in the making of glass so to answer your question, the heat will not be bad for the sand. Your temp will not get up to the glass making temp's.
I too have heard about leaving the floor "un-pasted" so that you can remove damaged brick. This is what I did however I really don't think that this is a major concern. So what if you get a cracked brick in your floor. I think the major concern for the floor should be the level or more to the point how flush each brick is to each other. You don't want raised edges which will catch your peel.

Gary

[Neil2]

"if one needs to replace a brick"

This is so rare (only once so far on this site) that I would not bother using this as a design criteria.