Archive for March 2010

So now if you have been following the series we’ve talked about fasteners in general and fasteners for metal and for wood. This time I want to talk about fasteners that you might use in concrete.

In many construction applications concrete anchors or fasteners must be used to hold a fixture or item of some kind to a concrete wall or floor. 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 to know what type of fastener and tools to use for the job. Much of this depends of course on the applications, such as the size and weight of the object to be fastened.

There are three basic types of masonry anchors: 1) mechanical, 2) powder-actuated and 3) chemical. Chemical anchors are rarely used unless you’re building a bridge, and in many states certification is required to use powder-actuated fasteners. This article describes how to use mechanical anchors.

When installing concrete anchors, special care must be taken to ensure safe and proper 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. You will need a hammer drill for drilling the concrete. The right size carbide bit for your particular anchor and also for drilling into the concrete, plus safety goggles or glasses, and a pair of gloves. Drilling into concrete or masonry is dirty work – dust and fine bits of masonry are created by the drilling process, and there’s the chance of a drill bit breaking and becoming a projectile.

The choice of concrete fastener to use is dependent on the specific application and personal preference.

So here are a few of the types of anchors:

Choose the Right FastenerTapcons are a popular type used. Tapcon® concrete screws are ideal for use in concrete, brick or block base material. The threads of the Tapcons actually cut threads into the base material providing excellent holding values. Each Tapcon® is coated with a Blue coating and this coating provides excellent rust resistance. All you need to do is drill a hole and turn in the screw, no anchor is needed. These are especially good if you want to be able to remove the object later. They will hold light to medium heavy objects.

Ucans are a similar product only it is a nail. You drill the proper sized hole and pound in the galvanized nail. This is a permanent fastener. They also will hold light to medium heavy objects.

Choose the Right FastenerSleeve anchors are another effective choice. This anchor is essentially a bolt with a sleeve over it. After you have drilled a hole through both what you want to hold and into the concrete the right depth. The sleeve anchor is inserted, then when you tighten up the nut on the bolt a wedge on the end of the bolt expands the sleeve and the bolt wedges tight into the concrete. These are very effective for fastening heavy items and I often use them to fasten the rim joist of a deck to a house.

Choose the Right FastenerPlastic and lead anchors are still used a lot today. With them you drill a hole in the concrete the right size for the anchor you’re using. Then you insert the anchor. Now you fasten the object you want to hold in place with a screw or carriage bolt depending on the size of the object and the anchor you are using. This allows the object to be removed in the future but this two part system is harder to line up and has been replaced a lot by the tapcons.

There are many more types of concrete anchors but these are the basic kinds that the average householder would use. Anytime something needs to be attached to concrete material around your home, it will require the use of one of these types of fasteners designed for use in concrete.