Anchoring To Concrete and Masonry

Anchoring objects into concrete or masonry can seem a daunting task, but is within the capability of the average do it yourselfer. The biggest issue is knowing what type of fastener and tools to use for the job. Much of this depends on the applications, such as the size and weight of the object to be fastened.

Because there is such a wide variety of anchors available on the market today, this article will explain in detail what they are, and for what application to use them for. The article will also discuss equipment needed, drilling the pilot holes, and the proper method of fastening.

When you set about to attach your project to concrete or masonry walls or floors, you will need some specialized equipment, and, as with any project of this nature, protective gear. Drilling into concrete or masonry is dirty work - there is the dust and fine bits of masonry created by the drilling process, and the chance of a drill bit breaking and becoming a projectile. To tackle this project, make sure you have the supplies listed.

Hammer Drill

Although a regular drill will work on drilling concrete or masonry, a hammer drill or rotary drill is almost a necessity. A hammer drill has a specially designed clutch that allows the drill to not only spin the drill bit, but hammers in and out to allow the drill bit's carbide tip to pulverize the masonry. The flutes of the drill then remove the debris from the hole as you are drilling. The hammering is very rapid, with thousands of blows per minute. You will be amazed at how easily you can drill holes in concrete or masonry with this specialized drill.

Although more expensive than a normal drill for woodworking purposes, it is well worth the investment. The hammering action can be turned off with either a switch or lever that releases the clutch, allowing the hammer drill to be used as a normal drill for woodworking or metal working. Because it can cover all of these different projects, it is worth the investment, as you have one tool for a variety of jobs.

Rotary Hammer Drill

A rotary hammer drill works much the same as a hammer drill, with the exception it uses an actual piston versus a special clutch. It is used for drilling larger holes, and packs a greater punch than a normal hammer drill. Because of this, many carbide drills are not adequate. Rotary hammer drills use a special shank that locks into the chuck of the rotary hammer to prevent spinning of the drill bit in the chuck. They come in three different configurations - SDS, SDS-MAX, and SPLINE SHANK.

Carbide Drill

Drilling into concrete or masonry requires a carbide drill. The flutes of the drill are generally relatively soft steel, machined versus ground as a normal drill is, and a carbide tip is brazed to the end of the drill to provide the cutting surface. It is essential you use the proper size drill recommended by the fastener manufacturer in any project, because if the hole is the wrong size, the fastener will not work properly. The drill must also be sharp, because a dull drill will often make the hole larger than it should be, making the fastener unstable.

Fasteners

Before you begin your project, consider the type of material you will be fastening to (brick, concrete, or masonry), what the fixture weighs, and what kind of load it will bear. This will guide you in choosing the proper fastener. If unsure, seek the advice of the hardware owner, or carefully read manufacturer instructions on the package.

Step 1 - Drill a Pilot Hole

Drill the pilot hole using a carbide tip in the base material, following manufacturer instructions for proper hole size. Blow out the hole, to clear debris, and be sure to use protective gear during this process.

Step 2 - Consider a Clearance Hole

Some fasteners require you to drill a clearance hole in the fixture for the fastener to work properly. Typically, this is 1/16" larger than the anchor diameter.

Step 3 - Install the Fastener

Install the fastener in one of several ways.

Using a one-step anchor, position the fixture over the pilot hole and tap the anchor fastener through the fixture.

If using a two-step anchor, tap the anchor into the pilot hole, position the fixture, and apply the fastener. Holding the fixture tight against the base material, tighten the fastener until fully seated. Use caution here - over tightening the fastener can break it.

If securing with a masonry screw, drive the screw into the pilot hole with a screwdriver or nut driver. This application is best for lightweight objects that will not have a heavy load.

If installing a drive anchor, insert the anchor through the fixture and into the pilot hole, and drive the fastener in with a hammer. Some drive anchors are removable.

Always bear in mind the proper drilling of the pilot hole determines if the installation is successful or not. Always use the size drill advised by the fastener manufacturer, and maintain a sharp drill bit. Use the correct fastener for the job. Invest in a hammer drill if you have a lot of projects requiring drilling into concrete or masonry. ALWAYS use protective gear. A shattered drill bit is a dangerous missile. Taking the time to do this job right ensures satisfaction.