Old Chimneys Will Cause Roof Leaks in Heritage Homes

chimney repair
ARS roofing technician caulking the counter-flashing while repairing a leaking chimney

If you own one of our fine old heritage homes in Greater Vancouver, you may be able to save yourself some grief from roof leaks by getting your chimney inspected.

One of the main causes of roof leaks in older homes that gets our guys called out on emergency service is the degraded condition of the chimney. If one of these older chimneys hasn't been inspected and repaired in the last 10 to 15 years, it is a surety that the mortar and caulking have degraded to a point that it is only a matter of time before a leak develops either around the chimney or down it.

When called out to repair a chimney leak, the first thing our roofing technicians check is the condition of the caulking on the flashings around the chimney.  Flashings are metal sleeves placed around a chimney or other items like roof vents that funnel water around them.  Caulking is then used to seal the flashings around the item.

There are two flashings used to waterproof a chimney.  The first one goes under the shingles and up the side of the chimney.  It is nailed to the roof itself. These are called step flashings as they step up the roof like shingles.

ARS technicians install a peel-and-stick waterproofing membrane on the chimney and the roof deck before the step flashing is installed.  This is part of the underlayment and provides additional protection around the chimney.  It is part of our reflashing procedures.

Then there is the counter-flashing.  This flashing hangs from the chimney and covers the step flashings. But this flashing hangs because it has flanges which slide into grooves cut into the chimney's mortar. This flashing is then secured by one of two methods.  The older method inserts the counter-flashing flange into the mortar joint which is then secured and sealed in place with mortar (sometimes caulking if it is retrofit). The second and better method is typical of new construction but it can be employed for repairs as well. This method is called gum-lip and is usually used when the original counter flashings have failed. The gum-lip counterflashing is installed on top of the brick-and-mortar and typically is secured with a concrete pin or another type of anchor.  Then the top edge is sealed with caulking to provide waterproofing.

The primary cause of leaks is that this caulking over time gets dry and cracks allowing water to flow between the chimney and the flanges.  The mortar holding the flanges can also wear away, providing spaces for water to leak between the chimney and the flanges. If the chimney is in a very degraded state, water could even be leaking from a cracked or broken chimney cap or other location.

While Absolute Roof Solutions has the expertise to repair these leaks, a homeowner with a heritage home would be wise to prevent them by getting their chimney inspected if they haven't done so in the last 10 to 15 years.

Our roofing technicians are qualified to provide this service which can be very important to a heritage homeowner's peace of mind.

To get your chimney inspected or repaired, give us a call at (604) 263-0334 or fill out our online form.