TOOLS:
Hammer,
stiff brush, mortar raking tool, trowel, joint filler, masonry chisel,
mortar hawk, pointing trowel.
MATERIALS: Mortar mix, mortar pigment (if needed), concrete
fortifier, spray bottle with water.
As
you can see in the picture on the left of a "badly in need
of repair" chimney, a failing chimney is both an eyesore and
potentially major problem if left unresolved. While the bricks themselves
might not benefit from any repair, the joints between them can be
successfully restored in a process called tuckpointing.
Tuckpointing
is a fancy word for the act of replacing crumbling & missing
mortar with fresh mortar. This prevents further deterioration of
the chimney due to moisture penetrating the failing joints and compromising
the chimney structure. It is not a difficult process and can be
accomplished in a few hours. Tuckpointing can be used on any structure
where blocks or bricks are bound together with mortar.
Start
by using the mortar raking tool to scrape any loosened mortar down
to a depth of a 1/4" to 3/4". Use a hammer and chisel
for difficult areas. Brush away the loose debris from the chimney
and then moisten the area with the spray bottle.
Mix
the mortar; then add concrete fortifier and pigment, if necessary
to match the existing mortar. Mortar should just 'hang' on the trowel
without being too sticky, should spread easily and shouldn't ooze
out of the joints.
Load
the mortar onto a mortar hawk, then press the filler into the joints
with a joint filler. Work the horizontal joints first, starting
at the top. Apply filler to a 1/4" depth, allowing to dry for
30 minutes, then reapplying until the joint is flush with the bricks.
Now,
work the vertical joints the same way as the horizontal ones.
After
applying the final coat, smooth the joints with a jointing tool
that matches the profile of the existing joints, starting with the
horizontal joints first.
Keep
joints moist with a spray bottle for several days. This will increase
joint strength by slowing the drying time.
