Tuck-pointing
Masonry homes and walls constructed of brick and stone can develop
voids, cracks, crumbling mortar, or uneven areas of mortar from settling
or foundation problems. Separations between brick and mortar can allow
air and water to leak through gaps in the wall. Repairing cracked mortar is
called tuck-pointing.
Tuck-pointing is typically needed when exposure (of 25-30 years) causes
mortar joints to crack, flake, or disintegrate. Large holes and washed out
mortar are typical signs that tuck-pointing is needed.
Although the right material and technique are usually enough to deliver a
water-tight job, it usually takes the skill of experienced professionals to use
the proper mortar mix and tools to match existing mortar.
The U.S. Department of the Interior Office of Historic Preservation has
established
standards to preserve the appearance of older buildings and to avoid
irreparable
damage during repointing and in the future. Often modern hard cement mortar
cannot
be used in older buildings because applying modern mortar over old lime
mortar can
result in serious damage to the original building materials and may not
last. It is
important that new mortar match the original in porosity and compressive
strength.