Repairing Brick and Block Walls

Most repairs to brick and block walls require only basic skills. Catching the damage and repairing it before it spreads wins half the battle for you.


Routinely check a brick or block wall's mortar joints. Soft, crumbling mortar joints let water in to cause serious damage to the wall. Faulty mortar joints call for tuck-pointing -- removing the mortar and replacing it. If the brick has lost its glaze, it's vulnerable to water migrating into its body. Seal the brick with a clear sealer. Chipped brick is also a tip-off that water has intruded and frozen. Treat a chipped brick as you would a damaged brick -- replace it. If you have ivy growing up the wall, its tendrils won't damage mortar that's in good repair, but the foliage can hide potential problems. Check the wall in the spring before leaves appear. To avoid collapsing a section of wall, replace only a few bricks at a time.

Prestart Checklist

About 2 hours to replace a brick or a block.

Small sledgehammer, masonry chisel, drill with masonry bit, pointing trowel, pointing tool, garden hose, scrub brush, plugging chisel, cold chisels, brick set, mortar box, mason's trowel, burlap, 4-inch grinder, old paintbrush, straightedge, circular saw and masonry blade

Chiseling, mixing mortar, pointing mortar

Muriatic acid, mortar, brick, stone, concrete block, wooden wedges

Tuck-pointing brick: Step 1

Adjust the blade of a 4-inch grinder to cut the mortar to about one-half its depth. With the rear of the grinder guard on the face of the brick, turn the grinder on, and ease the blade into the joint.

Tuck-pointing brick: Step 2

Brush the loose mortar from the joint with an old paintbrush. You can also blow out the dust on a small area with an air hose. In all cases, wear eye protection. After cleaning, mist the joint with a sprayer.

Tuck-pointing brick: Step 3

Replace the mortar in the joint by sliding it off the face of a flat trowel and into the recess. Use a narrow trowel or a thin piece of scrap wood to put mortar into the joint and not on the brick. Press the mortar into the joint until it's solidly filled -- mortar will start oozing at the edge of the tool when the joint is full.

Tuck-pointing brick: Step 4

Let the mortar set until it's fairly stiff and you can just dent it with pressure from your thumb. Then tool the joints with a striker that matches the profile of the original joints. Tool the horizontal joints first, then the vertical joints.

Replacing a damaged brick: Step 1

To remove a damaged brick, drill several 1/4-inch holes in its center. Next chip out the old mortar with a plugging chisel and small sledge. Using a brick set, break the brick into pieces and remove them. Brush away debris, blow out the dust, and dampen all surfaces of the cavity.

Replacing a damaged brick: Step 2

Mix latex-fortified mortar, tinting it with pigments if necessary to match the existing color. Using a pointing trowel, apply a 1-inch-thick layer of mortar to the bottom side of the recess.

Replacing a damaged brick: Step 3

Butter the top and ends of the replacement brick with mortar and set the brick on a pointing trowel. Slide the new brick off the trowel and into the recess, holding the trowel on the mortar in the cavity to keep it as undisturbed as possible. Pry the brick as necessary to make the joints evenly thick. Set a straightedge on the brick and push it level with the wall.

Replacing a damaged brick: Step 4

When the mortar has stiffened slightly, scrape away any excess with a masonry trowel and brush the area with a stiff brush. Let the mortar set up until it's fairly stiff and you can just dent it with pressure from your thumb. Then tool the joints with a striker that matches the profile of the original joints. When the mortar dries to a crumbly surface, brush it again.

Replacing a damaged block: Step 1

Use a masonry drill to drill holes into the cores of the block. Then chip out the mortar around the block with a plugging chisel and small sledge, being careful not to damage the surrounding blocks. Set a cold chisel in the holes and break out the front face of the cores.

Replacing a damaged block: Step 2

Using a cold chisel, chip out the block face just enough to leave all but the front 2 inches of the webs. This provides a bonding surface for the replacement face. Chip out the mortar on the sides of the recess also.

Replacing a damaged block: Step 3

Using a circular saw with a masonry blade, cut through the side webs at the thickness of the face and score the top and bottom of the center web. Then cut away the face from the center web with a cold chisel. Apply an inch of mortar to the perimeter of the new block face, as well as to the center and edges of the rear surface. Set the new face in place, slipping it in with a pointed trowel.

Replacing a damaged block: Step 4

Center the block face in the opening by driving wood wedges in the mortar. Let the mortar set up and remove the wedges. Then mortar the holes left by the wedges, and strike the joints.

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One Hour or Less

Three simple projects to cross off of your to-do list -- just print these instructions and begin!