Anchoring with bolts is one of the most common methods of attaching both structural, load-bearing walls and non-structural, partition walls to concrete foundations, including slab foundations and concrete foundation walls. For structural walls, high-strength adhesive called epoxy creates a strong bond between a bolt and the foundation. For partition walls, use a specially designed expansion anchor that's quick and easy to install. Learn how to add both types of anchor bolts to your existing foundation and choose the type that suits your project.
Attach a masonry drill bit to the hammer drill. Place the drill bit's tip against the concrete foundation. Position the drill perpendicular to the foundation's surface. Pull the drill's trigger and bore a hole into the foundation; drill the hole to the depth specified by blueprints or according to the epoxy manufacturer's guidelines.
Remove the drill bit from the hole. Suck or blow concrete dust from the hole with a shop vacuum or an air compressor. Remove all traces of dust and debris from the hole; epoxy will not properly bond unless the hole is clean.
Load a canister of construction-grade anchor bolt epoxy into an epoxy gun's saddle. Screw an epoxy mixing tip onto the end of the epoxy canister.
Place the end of the mixing tip into the hole, pull the gun's trigger and fill the hole with epoxy until epoxy nearly reaches the hole's brim. Insert an anchor bolt into the hole. Wiggle the bolt up and down to eliminate air pockets within the epoxy.
Seat the bolt at the bottom of the hole. Place a level against the side of the bolt and plumb the bolt; the term plumb refers to a straight up-and-down position. Wipe excess epoxy from around the bolt's base. Allow epoxy to fully cure before agitating the bolt.
Attach a masonry drill bit to a hammer drill. Drill a hole to the depth specified by expansion anchor manufacturer.
Vacuum or spray dust from the hole with a shop vacuum or air compressor. Place a washer over the expansion anchor's shank. Thread a nut onto the expansion anchor.
Place the expansion anchor into the hole, wedge side down. Hold the bolt plumb and strike the expansion anchor's head with a framing hammer or mini-sledge hammer. Repeatedly strike the anchor's head until the anchor's wedge expands and grips the concrete. Pull on the anchor to ensure it is fully seated.
If you are installing an expansion anchor through a sill plate, pre-drill a hole through the plate, position the plate on the foundation and proceed to install the anchor through the pre-drilled hole.
If you don't thread the nut onto the expansion anchor before striking, the anchor's threads will become deformed and prevent installation of the nut.
Tips and warnings
- If you are installing an expansion anchor through a sill plate, pre-drill a hole through the plate, position the plate on the foundation and proceed to install the anchor through the pre-drilled hole.
- If you don't thread the nut onto the expansion anchor before striking, the anchor's threads will become deformed and prevent installation of the nut.
Things you need
- Masonry drill bit
- Shop vacuum or air compressor
- Epoxy gun
- Construction-grade anchor bolt epoxy
- Epoxy mixing tip
- Anchor bolts
- Concrete expansion anchors
- Framing hammer or mini-sledge hammer