For many homeowners, installing hardwood floors is the most desired home upgrade. Beautiful wooden floors can help a room become a true showpiece. When properly installed and properly cared for, hardwood floors can last a lifetime.
If you’re making the investment of installing hardwood floors, you’ll want to be sure you do every step correctly. It is a project that DIYers can do, with some expert advice and the right tools and materials.
When installing hardwood on a concrete slab, furring strips are used. A concrete fastener is needed to attach this furring, which becomes the foundation for the hardwood floors. Many contractors use the flat countersunk split drive anchor. Use this anchor to attach the furring strips to the concrete floor, and then attach the plywood to the furring strips, and then lay the hardwood floor.
Split Drive Anchor
The split drive anchor is a one-piece pre-expanded expansion anchor made of carbon steel. It’s designed for use in a solid base material like concrete. It’s best used in in dry, interior, non-corrosive environments.
The drive anchor is used to permanently fasten. The only ways to remove the object fastened is to cut off the head of the anchor, destroy the object being fastened, or pull the anchor out to concrete failure.
Once installed, this anchor is tamper resistant.
How to Install Split Drive Anchors
The first step for installing a split drive anchor is to drill a hole in the concrete.
A hammer drill must be used when drilling a hole in the concrete for the anchor to be installed.
When drilling the hole in the concrete, the hammer drill must be set in the hammer and rotation mode.
The diameter of the hole to be drilled must be equal to the diameter of the anchor being installed. All of these anchors are 1/4”, which means that a 1/4" hole must be drilled.
The bit must have a carbide tip and meet ANSI standards. An ANSI standard bit will ensure that proper hole and anchor tolerances are met.
Make sure that the hole drilled in the concrete is a minimum of 1/2 inch deeper than the anchor will penetrate the concrete. This extra space at the bottom of the hole provides room for any dust and debris created during the installation process to fall out of the way.
The anchor must be installed a minimum of 1-1/8” into the concrete.
Proper and consistent hole depth is very important for installing drive anchors. To ensure correct and consistent hole depth, use the depth gauge provided with the hammer drill. To set the depth gauge, pull it out to the desired drilling depth and lock it in place.
If a depth gauge is not available, wrap a piece of tape around the bit to mark the correct drilling depth. If using a keyless chucked hammer drill, make sure that the bit is in the most protracted position when setting the drilling depth.
The minimum length of drive anchor to be used for any particular application is determined by adding the thickness of the material being fastened to the minimum embedment of 1-1/8”.
The length of the flat countersunk split drive is measured as an overall length; the round head is measured from underneath the head.
Drill a correct hole in the concrete using a hammer drill set in the hammer and rotation mode. The hammering motion of the hammer drill breaks up the concrete, while the rotation removes the dust at the proper rate.
To ensure hole alignment, drill the hole in the concrete while the item being fastened is in place.
Make sure that the hole in the item being fastened is large enough to accept the diameter of the bit being used. Split drive anchors require that the hole in the fixture be a minimum of 5/16”, slightly larger than the designated diameter of 1/4 inch.
Before the drive anchor is inserted into the hole in the concrete, the hole must be cleaned out of all dust and debris. This can be accomplished by using a wire 1/4-inch wire brush and a vacuum. Use an up and down motion while turning the wire brush. Vacuum the hole, and then repeat the process. This ensures that the hole is ready for the anchor to be installed.
Align the hole in the item being fastened with the hole in the concrete. Holding the head of the anchor, insert the split end of the anchor first through the item being fastened and into the concrete.
Using a properly sized hammer, strike the head of the drive anchor until the head is tight against the surface.