Attaching wood to concrete walls is a difficult task that, if done incorrectly, can lead to spectacular failures. Achieving success requires that you drive a nail deeply enough into the concrete with enough force to penetrate, without cracking the wood or shattering the concrete in the process. To accomplish this, you'll need to apply a specific process using tools created for the task. These powder-actuated tools, using gunpowder driven nails, make quick work of driving the nails into place, creating a hold that will keep the connection strong for years.
Things You'll Need
- 4-pound hammer
- Hardened steel nail fasteners
- Masonry bit
- Expansion fasteners
- Powder-actuated tool
- Power load
Determine if the concrete is suitable for the use of a powder actuated tool (PAT) by performing a center punch test. Remove the plastic flute from a fastener. The fastener is a hardened steel nail with a plastic flute above the nail-point that helps to guide the nail. Place the fastener against the concrete and firmly strike it with a hammer.
Examine the concrete for the test effects. A suitable concrete will gain an impression of the point of the fastener without that point being dulled from the striking. If the fastener penetrates deeply into the concrete, the concrete is too soft. If the concrete shatters, it's too brittle, and if the point of the fastener blunts or bends, the concrete is too hard.
Install the nails manually using an expansion fastener if the test fails. Drill a hole through the wood and concrete the size of the fastener and then place the fastener through the hole. Nail it into place to make the expansion sleeve on the nail billow out in the hole and create a secure hold for the nail.
Load the PAT with the power load if the test passes. Power loads are usually arranged into a magazine, which is fed into the PAT, or can be purchased as individual cartridges, placed for each fastener used. Choose a power load level that is compatible with your PAT. Power loads range from one through 12, with most tools able to utilize multiple loads across a range. Begin with the lightest load possible.
Place a fastener into the tool and test the power load. Place the head of the fastener against the concrete at an unobtrusive spot, with the PAT held at a 90-degree angle to the concrete. Activate the PAT by pressing down the tube of the PAT to cock it, moving the power load into place. Drive the nail into the concrete by firmly striking the firing pin on the top of the tool with the hammer. Brace yourself for the slight recoil as the tool fires.
Examine the test nail to determine if the power load is sufficient. If the nail is driven in completely, then the power load is adequate for the job. If the nail is only partially embedded in the concrete, load a higher power load and try again until you reach a load that is strong enough to pass the test. The fastener quickly compresses the concrete as it's driven in, and the concrete pushes back against the nail as it attempts to recover its original state. This action creates a strong compression bond between the fastener and the concrete, holding it in place.
Place the wood to be attached against the concrete. Load the PAT, and place the fastener against the surface of the wood, directed towards the concrete. Activate the PAT to drive the fastener through the wood and into the concrete.
Continue to drive the fasteners into the wood, keeping a minimum spacing of three inches between the fasteners.
Tips & Warnings
- Using a PAT can be dangerous. Attend a training class to learn the safety and operating procedures from an expert before using one.
- Check with local building codes to determine if there are restrictions to PAT use in your area.
- Always check the power load before loading it into the PAT to prevent injury.
- Wear safety goggles at all times while using the PAT, as protection against chipping concrete.
- Photo Credit 9 mm ammo image by Kostyantyn Ivanyshen from Fotolia.com
How to Attach a Bottom Plate to a Concrete Slab
Attaching a bottom plate to the concrete slab is the first step in building walls for new construction. The bottom plate must...
How to Bond Tile to Wood
There may be times when you want to bond tile directly to plywood, or another wood surface, rather than screwing down backerboard...
How to Attach Studs to Concrete Walls
A stud is usually a 2-by-4 piece of wood, but can also be a smaller width and referred to as a furring...
How to Fasten Wood Trim to Concrete Walls
Placing molding on a concrete wall can pose a problem. Concrete bricks are often hollow in the center. Pounding on the side...