When the fire pit at the edge of his beautiful patio started to crumble, our homeowner wasn’t sure what to do. After trying some DIY repairs that worked but probably wouldn’t last, he called the Ask This Old House crew for help. Mason Mark McCullough took over, removing the existing firepit and replacing it with one that would last for generations.
How to Install a Granite Slab Fire Pit
- Wearing your safety glasses, start by demolishing the old fire pit. Use the sledgehammer to strike the side of the pit to break it up. Remove the large chunks with a wheelbarrow, then pick up any remaining small pieces with the shovel.
- Using a combination of picking and shoveling, dig the footing for the fire pit. Dig about 12 inches deep, or until you hit solid, compact ground.
- Install about six inches of gravel in the footing for drainage and a stable base. Compact the gravel with the hand tamper to lock it into place.
- Use a 4-foot level to check the gravel for level, knocking down any high spots and filling low spots as needed.
- Use the small sledgehammer and the masonry chisel to knock down any high edges on the sides of the inner slabs. This will allow the slabs to sit closer together, with fewer gaps, once installed.
- With several strong helpers and some lifting straps, lift the granite slabs into place. Carefully place them on the gravel and check them for plumb and levels. Use the trowels to add or remove gravel under the slabs as needed, being careful not to place your hands under the slabs.
- Once all of the slabs are in place and level, add lava rock inside the firepit, a few inches deep.
Materials
- Lifting straps
- Gravel
- Granite slabs (Can be found at a local stone yard)
- Lava rock
