Encyclopedia

of Home Improvements

*Masonry Anchors*

One caution when installing masonry anchors-always wear eye protection and follow the manufacturer's safety instructions. When choosing anchors, remember that the total load should be divided by the number of anchors that will carry it.

Whatever type of anchor you decide to use, you'll need a hammer drill to drill the holes for it. Masonry drill bits work by chipping concrete away. If you use a standard electric drill, you'll find that it not only drills much more slowly, but you'll be much more likely to ream the sides of the hole and wind up with a hole much larger than you intended.

The holes have to be exact in diameter and sometimes even an exact depth in order for the anchor to work properly. Some manufacturers' anchors must be installed with special drill bits. For best results with masonry anchors, it is important to "blow out" any excess dust from the drilled holes.

Most masonry anchors work in one of two ways-either by expanding against the sides of the hole and gripping the concrete or by friction against the sides of the hole. The holding power of any anchor depends on the quality of the concrete and on where the anchor is placed. If the concrete is old and crumbly, the holding power of the fastener will be reduced.

Likewise, if the anchor is placed near the edge of the concrete-or two anchors are placed too close together-the force generated by the anchor may break the concrete.

Plastic anchors are used with standard wood screws.

Lead lag shields are designed to be used with standard lag screws.

A wedge anchor and a sleeve anchor

A Ramset gun shoots hardened nails into concrete

A concrete screw cuts its own thread in the masonry.

Hammer anchors are a good choice for anchoring furring strips to a masonry wall.

Back to Topics Page

Contact