4 Ways to Fasten to Concrete
Updated: Mar 12, 2018
For most homeowners, trying to screw or nail into concrete is a near-impossible task. But, attaching to concrete really isn’t much more difficult than fastening to wood—if you use the correct tools and specialized fasteners.
Here, I’ll discuss four different fasteners that are specifically designed for attaching to concrete. Most of these fasteners can also be used in brick, stone and concrete block.
Before installing most concrete fasteners you must first drill a hole using a carbide-tipped masonry bit. Now, the quickest, easiest way to drill into concrete is with a hammer-drill, which uses both bit rotation and concussive blows to bore holes. If you don’t own a hammer-drill you can use a standard drill, but it’ll take two to three times longer to drill each hole.
It’s also important to blow or vacuum out the concrete dust from the hole before inserting the fastener. Fasteners grip much more tightly to clean, dust-free holes. Okay, let’s take a look at four different types of concrete fasteners:
For light-duty attachment, it’s hard to beat the speed and ease of hammer-set anchors. Each anchor consists of an unthreaded pin set into a metal sleeve. Simply drill a hole into the concrete, hold the fixture you’re fastening over the hole, then use a hammer to tap the anchor into the hole. As the pin is hammered in, it expands the sleeve outward, trapping the anchor in the hole.
Hammer-set anchors (shown at right), also known as nail anchors, typically require a ¼-inch-diameter hole, and come in lengths ranging from 1 to 2 inches. A 50-piece box of 1¼-inch-long anchors costs about $8. Hammer-set anchors are perfect of attaching metal electrical boxes, wood furring strips, conduit, and shelf brackets to concrete, block and brick. However, be aware that you can’t remove and reuse them.
The soft-metal shield is one of the oldest—and most effective—concrete fastener available. It’s little more than a ribbed, slightly tapered metal sleeve that fits into a hole. However, because the shield is made from soft, almost lead-like material, it provides the perfect surface for threading in a sheet-metal screw.
When installing a soft-metal shield it’s important to drill the proper-sized hole. If it’s too large the shield will spin in the hole, and if it’s too small, the shield will crush when you tap it in. Also, be sure to clean all dust from the hole prior to installing the shield.
Soft-metal shields (shown below) are commonly available in lengths ranging from ¾ to 1½ inches. Expect to pay about $6 for a box of 50 shields. Sheet-metal screws must be purchased separately. The shields can be used in concrete, block and brick.
Concrete screws (shown below) represent the newest and most popular way to fasten to concrete—and it’s easy to see why. All you must do is drill a hole and then drive in the screw. There’s no hammering required or additional anchor or shield to install, and the screw can easily be removed, if needed.
The screws feature specially engineered high-low threads that bite tightly to the sides of the hole. To ensure a solid attachment, be certain to use the drill bit recommended by the screw manufacturer, and bore the hole about ¼ inch deeper than the screw length to avoid bottoming out.
Concrete screws come in 3/16 inch and ¼ inch diameter in lengths up to 3¾ inches. Both hex-head and Phillips-head styles are available. They can be used in concrete, block and brick. Expect to pay about $6 for a box of 50 screws.
If you don’t think fastening to concrete can be fun, then you’ve never used a powder-actuated fastener (shown below, right). This tool is essentially a .22-caliber pistol that fires hardened nails into concrete. Now how cool is that? (Some manufacturers also offer .25- and .27-caliber models.)
Powder-actuated fasteners are ideal for securing 2x4 sleepers to floors, furring strips to walls, and plywood subfloors to slabs. They provide an incredibly strong and fast way to attach to concrete, but, of course, you can’t remove the nails once they’ve been fired in.
The gun accepts a wide range of nails, called pins, ranging from about ½ to 3 inches, and various charges, also known as loads. The larger the load, the more gunpowder it contains. Loads are numbered and color-coded for easy identification, ranging from Gray No. 1 (least powerful) to Purple No. 6 (most powerful). Which load to use depends on several factors, including the nail length, thickness of material being fastened, and hardness of the concrete.
Be aware that a powder-actuated fastener is a potentially dangerous tool. Use it to only fasten to poured concrete, never to concrete block, brick or any other surface. And always wear safety goggles and hearing protection.
Powder-actuated fasteners come in a wide range of prices, starting at about $75, but you can also rent one for about $40 per day, not including pins and loads. Expect to pay about $12 to $20 for a 100-piece box of 3-inch pins, and about $8 for the same number of Yellow No. 4 loads. Finally it’s worth mentioning that for about $20 you can buy a manual powder-actuated fastener that you hit with a hammer to fire the load.