Red brick was used for foundation construction in the early 1900’s. It has been our experience that as these foundation walls age the mortar joints and red brick both deteriorate. The deterioration of the red brick is visible as scaling or peeling of the brick surface and the bricks may even be disintegrating into a powder.
As the foundation walls deteriorate they lose strength which can lead to inward bowing. This inward bowing is the result of the inability of the weakened foundation to resist the lateral or inward soil pressure. This lateral earth pressure increases significantly as the soil becomes saturated with water. Unfortunately with older red brick foundations the problem of saturated soil is made worse as perimeter drain tiles were rarely installed. This is usually evident as the basement area may be wet.
If just the mortar joints are deteriorated and the foundation walls are not cracked or bowed, and the objective is to simply extend their service life, then the solution may be as simple as cleaning and tuck pointing the mortar joints. If water penetration is an issue, then the exterior may have to be excavated and a perimeter drainage system installed. At the same time this is done, the exterior of the foundation walls should also be cleaned, tuck pointed, parge coated (covered with a layer of mortar), and water proofed. Care must be taken when back filling red brick foundation walls so as to not damage them with the impact of the back fill material.
If the mortar joints are deteriorated and the wall has developed cracks or is bowed inward, then the foundation may have to be replaced or reinforced with a new concrete wall in front of it. In most cases replacement is generally the better of the two options for several reasons:
- Replacement allows for the installation of an exterior drainage system.
- Even with a new concrete wall in front of a brick wall the red brick will continue to deteriorate.
- In ballooned framed construction, which is typical with older homes, the weight of the structure is bearing on a sill beam (typically 8×8) over the red brick. This weight does not transfer back to a concrete wall installed to the inside.
- Red brick foundations generally do not have a footing. Installing a new concrete wall to the interior adds significant load which must somehow be properly supported.
Unfortunately bracing a red brick foundation wall with vertical steel beams is not a viable option as the wall will continue to deteriorate, bow, and crack between the vertical braces.