Attachment of a stone fireplace surround — fasteners?
Is it a code requirement or recommended practice to install mechanical fasteners to fireplace surrounds, or is mortar alone satisfactory? I’m not talking about massive columns and mantles. Just thin granite slabs (not tile) without a mantle. More specifically:
I’m installing a wood-burning fireplace surround. It’s a very simple design—-2cm granite slabs (not tile, just whole one-piece slabs) about 14″ wide (1 top slab and 2 side slabs) without a mantle. My plan was to simply attach the slabs to Hardi with medium bed mortar and call it done. But in a general google search about fireplace construction, I ran across a “best practice guide” that highly recommends mechanical fasteners—see attached link from the Stone Federation (in the UK). I’m not in the UK, but physical science doesn’t have borders ……..well some of it apparently does, but that’s another topic 🙂
I can’t find anything in the IRC code about this, but was told by one of the mortar manufacturers that it is a code requirement (they couldn’t cite where in code) to have fasteners on fireplace surrounds.
Note that the Stone Federation data sheet cites fatalities and serious injuries from fireplace surrounds collapsing. So, on page 2 of that document they have a general solution.
At first, I thought I would just use their drawing for my installation. However, it appears to me that their solution is more suited for thicker slabs. If I use their solution for my 2cm slab, that doesn’t leave much stone for the brackets and dowels to hang on to after cutting the grooves and drilling the dowel holes.
Note that my design is similar to the one in the UK drawing, but doesn’t have the bulky top and bottom pieces. I just have flat slabs with no mantle.
I would appreciate any comments on this.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part