Ways to Tie Down the Bottom Plate on a Slab

Exterior Sill Plate

• Sill plate is a kind of bottom plate, but it should be distinguished from interior walls. Exterior walls typically have a perimeter of pressure-treated sill plate. It's often wider -- 2 inches by 6 inches rather than 2-by-4 -- to accommodate insulation requirements. And it must have a mechanical connection to the slab. Anchor bolts are set into the perimeter of the slab or the stem wall sitting on the perimeter of the slab. Holes are drilled in the sill plate. The sill plate is slipped over the bolts and secured with washers and nuts.

Interior Bottom Plate

• Interior walls are typically 2 inches by 4 inches. They don't require pressure treated wood, but they do require a solid connection to the concrete. The connection does not generally have to be as strong as an exterior wall. Construction adhesive, generously applied will create a strong wood to concrete bond, so long as the concrete and wood are clean when they are glued.

Ramset

• A Ramset is a highly specialized nail gun. It shoots concrete-penetrating nails. Ramsets are designed like firearms, with a steel breech. They use cartridges from .22 caliber rifle shells. The tip of the Ramset is placed straight down on the wood with special masonry nail and cartridge loaded. The back of the Ramset is struck which sets off the primer and cartridge just like a firearm; in some Ramsets, there is a trigger, just like a handgun. Firing the Ramset drives the nail through the wood, flush into the concrete in one shot. They are often used in conjunction with construction adhesive.

Drill and Epoxy

• For stronger mechanical connections, you can drill a hole in the bottom plate with a wood bit. Then, drill a hole in the concrete with a masonry bit. Partially fill the hole with masonry epoxy, then insert a piece of threaded steel. When the epoxy dries, you can install a washer and bolt the bottom plate down.

Wedge and Strike Anchors

• Wedge anchors are an alternative to epoxy systems. Holes are drilled in the same fashion. Specialized wedge anchors or strike anchors are inserted without the need for epoxy. These systems require a hole diameter the same size as the anchor diameter.