It doesn't
take a lot of skill to make repairs in concrete walks and driveways.
It takes some muscle, however and you can get wet and dirty. The
money you will save and the rewards of doing it yourself are worth
it. There is one caution: always, without fail, wear safety glasses
and heavy gloves when chipping concrete. In this How-To Booklet
you will find patching techniques to make repair jobs go easier.
We can't offer any special pointers on how to keep you dry and clean.
PATCHING
CRACKS:
One of the most common masonry repair jobs is patching cracks in
concrete. Before you patch the area, first determine what is causing
the crack, if possible. If the crack is a structural problem, it
must be corrected; otherwise, the crack will simply keep getting
larger and larger.
For
shallow cracks in concrete, break out all old and crumbling
edges from the crack, and, if possible, make the crack about 1 inch
deep-if it isn't already. Use a baby sledge hammer and cold or brick
chisel for this.
The sides
of the crack should be vertical; the hollow will form a sort of
key for the patching material. The trick is to create a new area
that is wide and deep enough so you don't have to feather out the
new cement to a thin edge. Thin edges break.
Remove
all dust and debris from the area with a broom. Then flush the surface
with clean water. Sweep away the water with a broom, so there is
no open, standing water. The area should be damp with water, however.
You can buy already-mixed or ready-to-mix concrete patch. Or you
can mix your own: 1 part mortar cement to 4 parts sand. Make the
mixture "soft" and "mushy."
Fill
the crack or cavity with the mixture, using the straight edge of
a board to level it. Then let the job set for about 20-30 minutes
and finish the surface with a trowel so it matches the surrounding
surface. If the patch is in a vertical surface, make the concrete
mix thicker.
Note: You can buy special bonding materials that can be brushed
onto the area and mixed with the cement to help hold the patch in
place.
Shallow
holes-
Use the very same technique as above to patch shallow holes in concrete.
However, larger surfaces, such as holes, should be roughened first
with a cold chisel to help hold the patch in place.
Holes
in new concrete walls-
Sometimes you will see holes in newly placed concrete walls. This
is due to improper tamping or because aggregates in the mixture
have lodged in center spots. For these holes patch according to
the steps detailed above.
If, when
cleaning out the hole, the hole becomes larger and larger (as it
sometimes tends to do), you can punch a hole in the good, firm concrete
and drive in a metal pin such as a carriage bolt, and then make
the patch. The bolt helps hold the concrete in place. The pin must
be 1/2-inch lower than the finished surface.
