House Shopping 101: Brick Behaving Badly
by Keith Tripp
Revised 2021. Text to 416 320 8863
We build houses with brick, yet brick and water don’t do well in our cold climate where the freeze-thaw phenomenon takes it toll. Why isn’t the brick on houses all falling apart? Water management and a bit of warmth are the key.
The best examples of brick failure can be found on garden walls and those proud entrances to pseudo-gated community subdivisions built in the 1980s, followed closely by chimneys built in the 1980s that didn’t meet common sense or even code requirements at that time. The failures are caused by lack of water management. In the photo of the wall, the brickwork has exploded from freeze-thaw action. Water enters at the top of the wall where fenceposts are embedded in the wall and flashings are inadequate or damaged. The parging efforts on the wall will have little benefit and may even reduce the ability of the brickwork to dry to the outside. The wall also fronts on to a parking lot meaning it will be exposed to snow and salt. The other factor is that this is a “cold” wall. It is not attached to a house that could provide a warming effect.
This 50-year-old brick veneer wall shows spalling caused in earlier days when the downspout was leaking against the wall. Brick veneer walls can tolerate some water because they can dry to the exterior, have an air space behind the brick and drainage capability through the weep holes. They also receive some warmth from heat loss through the house walls. However, concentrated and long-term water exposure will cause damage. Brick veneer damage is most commonly found where downspouts have been leaking, or close to ground level at the front of houses where snow and salt take their toll.
|This particularly severe failure on a brick veneer wall, about 40 years old, posed a bit of mystery as to the water source. There was a flat roof on the house. It appears the water has contacted the wall from the top down as if it had found its way in to the soffits. The brick also appears to be very susceptible to water damage. No specific water source was identified. It may have been related to roof leakage that had been repaired before the inspection.||
This townhouse is not that old, and the deterioration of the exterior veneer wall is caused by poor water management. The fancy design features have caused water to flow directly from the roof down the wall. Note that a strip of metal has been added to the roof in an attempt to divert water. Repair to brick at this height and location ( over a City sidewalk) could be very expensive.
This Oakville chimney is disintegrated at an early age of 27 years, and soon will be at risk of collapse. It was built without good practices that have been understood for many years, and probably did not even meet the code requirements at time of construction. It has no chimney cap and drip-edge to shed water away from the brick. To make things worse the brick is corbelled, creating ledges to catch the water. These failed chimneys are a common find on 1980s houses across the GTA. Longevity of masonry chimneys depends on design and characteristics of the brick. Some formulations of brick fail quickly. Often chimneys built in the 1960s and 1970s will outlast chimneys built in the 1980s onwards.
This triumvirate of Oakville chimneys are all destined to early failure because of poor construction practices.
There are two house shopping tips buried in this rubble:
1) The chimneys are a good example of why you should still worry if you have purchased a new home and the builder is telling you “Don’t worry, everything has been inspected and approved by the City”.
2) If buying a 1980s house with a masonry chimney: look up and expect the chimney to be in worse shape than found on houses built in the 1950s and 1960s.
|This early 80s chimney also is not doing well. Even though it has a concrete chimney cap, it is not effectively diverting water away from the surface of the brick, and this brick appears to be particularly susceptible to freeze-thaw damage. An expensive repair. The most viable long-term plan often is to remove the chimney, ideally to below the existing roof level so it can disappear completely without any remaining protrusion through the roof. This eliminates any flashings or other sources of leakage. Timing of the work will be impacted by age of the HVAC system and age of the existing roof covering. The new furnace and/or water heater will vent through the wall and requires no chimney.||