mortar mix for oven floor

[pmac]

Hi
trying to decide best mix for laying fire brick (230X115X64) floor - dry or wet refractory mix? are there pros and cons with both?
am laying onto of Calsil board, cut to plan of oven.
Thanks

[downunderdave]

Oven floor bricks are usually laid loose to better cope with the uneven expansion they experience. This also makes any floor brick replacement easier. The gaps between the bricks simply fill with ash. If the floorbricks are uneven then a thin bed of dry mix 50/50 sand and powdered clay is the usual leveller.