Clean bricks before remortaring
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Photo 1: Chip out old mortar
Chip away the old mortar with a cold chisel or flat
utility chisel. Hold the chisel at a low angle, work it in
under the mortar and hit the chisel with short, light
hammer blows. Dust out the cavity using a whisk broom
and dampen it with water to improve mortar adhesion.
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Photo 2: Clean the brick
Knock the mortar off the old brick by
holding the chisel at a high angle and
hitting it with rapid, light blows while
moving the chisel tip quickly over the surface of
the hardened mortar. Clean the brick with a
wire brush and rinse it off with water.
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Photo 3: Apply new mortar
of mortar to
the bottom, both
sides of the cavity
and the top of the
brick. Slide the
brick into the cavity.
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Photo 4: Point the mortar
joints with a brick
trowel and 3/8-in.
wide pointing tool.
Add more mortar by
sliding it directly off
the trowel and into
the joint. Finish the
joint surfaces to
match the shape
of adjacent joints.
When a brick works loose, you can’t just shove
mortar in around it and expect the repair to
last. Pull it out and fix it right.
It’ll take you at least 20 minutes to remove a loose
brick from a wall and clean off the old mortar from both
the wall cavity and brick (Photos 1 and 2). If possible,
reuse the old bricks. New brick will never match the texture
or aged color of the original.
When resetting bricks, follow these guidelines:
- Select bagged mortar mix, not
sand or concrete mix.
- Wear safety glasses. Also wear waterproof gloves;
mortar contains alkaline chemicals that can burn you.
- Add latex additive to the water and
mix the mortar in a shallow container (like an old
dishpan) to the consistency of peanut butter.
- Mix small batches of mortar. Hot, dry weather and
direct sunlight can reduce the viable working time of
the mortar from 60 minutes to 30.
- Immediately clean mortar smears off brick faces using a
soft-bristle brush (a wire brush may leave rust marks).
If the mortar dries, you’ll have to use chemicals to remove it.