Masonry Anchors

Step 1: Determine the type of anchor

Step 2: Determine where to drill the hole

Anchors shown in Figure 141 must be installed in specific areas of hollow block and in-filled block. See Figure 142 for approved anchor hole locations when using any of the concrete block anchors shown in Figure 141.

DO NOT POSITION THE HOLES IN THE HEAD JOINT. Carefully note the location of anchors in the face location, centered face location, and bed joint as they apply to different anchors.

Determine the depth and location of any steel reinforcement in grout-filled block walls or brick before drilling. This may require relocating equipment slightly to miss reinforcement.

When using electronic locating devices to find reinforcements and tendons, make sure you know the limitations of the device. Calibrate and test with a known standard or location to confirm accuracy. Check the area of concern in two directions. Inform the contractor performing the work of the precession of the test unit and record the results. For example: agreed upon mark +/- ¼” location vertical, horizontal, and depth +/- ½”.

Step 3: Drill the hole

Drill the right-sized hole for the anchors. Use the appropriate ANSI-rated drill bit for the application.

Use masonry drill bits for brick and block.

DO NOT CUT STEEL REINFORCING WHEN DRILLING HOLES.

If you strike steel reinforcement when drilling, you must have damage inspected. As directed, fill the hole with approved grout and select a new location according to minimum spacing requirements. Drill a new hole.

Holes for concrete screws are small than screw size. See the manufacturer’s instructions for specific requirements.

Step 4: Clean out the hole

Drilled holes must be cleaned before you can insert the anchor. Use clean, dry compressed air to blow out dust and debris. The type of anchor or application also may require you to use water or a brush.

See the anchor manufacturer’s instructions for cleaning the hole.

Cleaning is important: a “dirty” hole can significantly reduce an anchor’s performance.

Step 5: Insert the anchor

The following anchors use different insertion methods.

• Adhesive screen anchor in a brick wall or hollow block wall.
• Adhesive anchor in a hollow block wall.
• Concrete screw.
• Toggle bolt.