Leakage around a chimney is not always related to the roof flashings surrounding the base of the chimney. The chimney counter flashings, the mortar between the bricks, the chase caps or top of the chimney and the bricks themselves can all be involved in the cause of the leakage.
Wind-driven rain beating against the chimney face soaks into the mortar causing the mortar joints or the bricks to crack over time. Expansion and contraction of the chimney’s counter flashing can result from temperature cycling. This fractures the mortar joint that the flashings are embedded into at the base of the chimney. Freeze/thaw cycling of a water-soaked chimney leads further damage and deterioration.
Chimneys need to be repointed every 5 to 10 years to repair cracked or damaged mortar. The counter flashings should be inspected and replaced if necessary. Then two coats of sealant should be applied to the entire chimney.
When repointing, the damaged mortar is removed carefully to a depth of twice the width of the mortar joint and new mortar is applied. Chemicals can be added to traditional mortar, creating a reaction that causes long, narrow crystals to form in the pores and capillaries of the mortar. Once the mortar has cured, the crystals remain dormant until exposure to moisture causes the crystals to grow, filling any new cracks or fissures. The seal-seal characteristic of this modified mortar dramatically reduces long-term maintenance and repair costs.
At Westcoast we have the knowledge, experience and skilled workers required to repair and maintain any type of chimney. We use the latest advancements in self-sealing mortar technology.
Tip: Many factors explain price differences you might see when comparing estimates for “servicing a chimney”.
They include: the depth of the cuts into the mortar, the gauge of flashings, the treatment of the cold joint between the old mortar and the new, the higher cost of chemical additive mortar, the type of sealer, preparation and number of coats, and the labour time to perform the work.