We are considering using small landscaping blocks to create a large wood stove hearth that will extend into a living area maybe 10 feet square. The blocks are small and various sized that layout like a puzzle to form 2'x4' square area's. I'm hoping to make this easy by using silicone adhesive around each block on its 4 edges and using liquid nails to adhere the block to the sub floor, 3/4 Advantech. I am trying to eliminate the need to grout and use the typical concrete adhesive base to make this easier. Any opinions on this idea I have pro or con would really be appreciated. BTW the blocks look to be maybe 1-1/4 -1-1/2 thick with a slightly rounded top edge, would make a really cool looking hearth/floor section. Thanks for any suggestions, Regards Walt
One idea with random sized material is, build an upside down form the shape, size and thickness you want the finished product to be. Place the material inside the form, puzzle fitting it in to your liking, then lay mesh wire over it and pour concrete over it all. Get help flipping it over and into place and strip the forms.
If you know what woodstove you're going to get make sure your blocks will meet the safety requirements. Some stoves want a certain R value underneath so you have to stack a bunch of sheets of durock if your stones aren't thick enough. I'm not really an expert on that.. just something I was reading up on recently for my woodstove (my manual says R-value = 0 so I guess I could technically stick it right on a hardwood floor).
Only other thing I could think of is to make sure that the glue can handle the heating/cooling cycles. Of course I'm guessing the sun heats up that glue as much or more than your wood stove will...
I glanced through a code book involving wood heating equipment recently, and I think it was pretty specific about any sort of grout being official fire-proof grout or some such. Might be worth researching a bit further.
David