I am about to install a fireplace hearth using a wood door for the base with a slab of granite on top. Does anyone know if the granite will crack? This is a raised firebox, approximately 12" off the floor, and is gas. The tiles above the firebox get warm to the touch, nothing below gets heated.
Also, will it be attached securely if I use liquid nails to attach to the tile floor and caulk around that or do I need to nail it to the slab?
We have a restaurant in the family. the rib or Bbq grill is surrounded by Black Cambrian granite I had fabricated and installed, around the immediate grill (2-3 inches next to the fire) the granite cracked but a few more inches away the granite was hot enough to cook an egg but no cracks. The granite would have to be really close to the fire for it to damage, the way you are describing it (warm to the touch) you would have no issue. Liquid nail I am not familiar with but I use Lepage Premium Pl to glue under mount lavatories to granite tops and they don’t fall down, if liquid glue is the same , it would be very solid. and if you do decide to anchor it mechanically, you cannot nail it to the slab as you would crack your tiles. You need to drill through and use proper bits screws and anchor systems.