Can bricks left over from the refurbishment of a cremator be used for at least the floor or even the whole dome or will the rating be too high? The bricks are new (unused) and free to me but I'm concerned they are the wrong type ie rated for use over 1000 degrees Celcius? Plan B - can clay bricks with the holes through them be used for the construction of the dome or will they crack not being solid? Again I have access to several 100 at no cost to me. Thanks in advance for any reply. Be gentle, guys, am having information overload!!!