Re: please do not crack

Posted by Rado (144.134.145.123)

In Reply to: please do not crack posted by Chris

Chris,
The hearth slab expands on heating, it moves just very little but this expansion could create cracks. You can sit the top slab on these inner walls. If you would like to extend the surface by making top slab all the way to the outside of outer wall edges it would help if the concrete was prevented from bonding to the limestone deco, put some flat board pieces in between before pouring the slab. Lime stone on outside can will look nice, how about this; make the slab size only over the inner walls and then rise limestone deco to this slab's surface level it'll be hidden. From this limestone level (does not even need to be in precise water level) then you can continue with final deco and insulation under. Reinforce the slab with metal well. Email me pictures on how you go: pizzapaddle[at]gmail[dot]com , large to see detail well.
Have you seen my oven building CD-s(?), between the outer and inner walls there is a gap stopping the slab expansion pushing onto outer decorative parts so it can expand freely. r

Re: please do not crack