Safely drilling into concrete takes the right tools and a little preparation
Don't let a concrete wall or floor stop you from completing your project. Learning how to drill through concrete can seem difficult, but what looks like a fairly hard job is made much simpler when you have the right tools and the proper technique.
What You Need
• Measure and mark the spot on the concrete where you want to drill a hole.
• Check to be sure there is no infrastructure behind the concrete that might be damaged in the drilling. Check for water pipes, electrical wiring, or ductwork.
• Set the depth stop on the drill to ¼-inch longer than the depth you want your hole to be. If the drill does not have a depth guide or stop bar, wrap a little piece of masking tape around the drill bit at the required depth mark.
• Fit the hammer drill with a carbide masonry bit of the desired size.
Safety: When drilling into concrete, wear safety goggles, work gloves, ear protection and a mask.
When you purchase concrete screws, the correct size drill bit is often included in the pack. Otherwise, get a 5/32-inch bit for concrete screws that are 3/16-inch in diameter and a 3/16-inch bit for ¼-inch screws. Be sure to keep spare bits in the correct size on hand as working in masonry can wear out a bit quicker and result in improperly drilled holes.
If appearance is not an issue, purchase hex head concrete screws, which are easier to work with than flat-head screws.
• Assume a stable stance, feet shoulder-width apart.
• Grip the drill in one hand; if the drill doesn’t have an auxiliary handle, brace the back of the drill with your non-grip hand.
• Position the tip of the drill on the mark you made on the concrete and keep the drill perpendicular as you drill.
• Start the drill at its lowest speed for better control.
• Drill forward with steady, light pressure; do not force the drill.
• Drill the guide hole to a depth of 1/8- to ¼-inch.
• Stop the drill, sweep or blow away the accumulated concrete dust and pull out the drill.
• Blow away dust that accumulated in the guide hole.
Tip: Do not press forward on the drill with all your weight as too much force could break the drill bit.
• Replace the drill in the pilot hole, ensuring that the drill is perpendicular surface.
• Start the drill and push forward with firm but not heavy pressure.
• Run the drill at a slow to medium speed and pull the drill out periodically to help remove concrete dust from the hole.
• If you encounter an obstruction, stop the drill and remove it from the hole, then insert a masonry nail with the tip touching the block.
• Tap the masonry nail lightly with a hammer to break up the obstruction, but do not drive the nail in completely.
• Remove the nail and resume drilling.
• Once your hole is the correct depth, stop the drill and brush away the accumulated concrete dust outside the hole. Then remove the drill from the hole and vacuum or blow out the hole to remove as much dust as possible.
If the threads of a screw won't grip, you can try to drill a new hole and relocate the screw. If this is not possible, use an anchor.
• Match the correct anchor size to that of the concrete screw.
• Expand the drill hole to accommodate the anchor. The hole should be slightly smaller than the maximum width of the anchor.
• Remove any concrete dust, then press the anchor into the hole until it is flush with the surface. If necessary, tap in lightly with a hammer.
• Insert the concrete screw into the anchor and drive into the wall until secure.