Anchoring into Masonry

Safety

Cables and water pipes are behind walls; scan, and drill shallow first. Dust in eyes and lungs. A drill that catches will twist your wrist — hold it with both hands.

Steps

Scan for cables and pipes; then mark the holes off the level fixture, not the wall.

Drill in brick, not mortar joints; drill to the depth of plug plus 10 mm, hammer on.

Blow or vacuum the dust out of the hole — dust halves the holding power.

Push the plug in flush; drive the screw until firm, not until it spins.

For heavy loads use sleeve or chemical anchors and drill the specified size.

Load-test by pulling before you trust it.

Tools

Hammer drill or SDS drill, masonry bits sized to the anchor, wall plugs or sleeve anchors, a detector for pipes and cables, tape and pencil, spirit level.

The Science

A wall plug or expansion anchor works by friction: it swells against the sides of the hole as the screw drives in, and the pull-out strength comes from that friction times the contact area. That needs a hole of exactly the right diameter and depth in sound material — a loose hole or crumbling brick and the anchor spins. Hammer drilling pulverises masonry with a percussive carbide tip; the drill's rotation only clears the dust.

How It Fails

The plug spins in the hole — hole too big or brick soft. The screw pulls out under load. Cracked brick from drilling in the edge or the mortar.