Chimney Flashing and Your Roof
Improperly repairing a leaking chimney can cause more problems. When your roof is leaking around the chimney then you know you have a problem that won’t go away. It needs to be addressed otherwise water will come in every time it rains.
If the chimney is leaking around the base, or where the roof meets the brick, then it likely needs to be re-flashed. That is the metal around the base needs to be taken out and new metal installed. This is not a job for the inexperienced.
We see all sorts of failed attempts at a cheap fix. Some done by the homeowner, but all too often the repair is performed by a roofer that isn’t completely trained in how to re-flash a chimney. This is one of the more complicated roof repairs a homeowner will be faced with.
We recently saw such an attempt on a chimney. The person trying to repair it applied some type of asphalt based sealant to the flashing in hopes of stopping the leak. I don’t know what they used, it may have been driveway sealer. As you can see from the picture it was clearly not the appropriate material.
Asphalt is waterproof but it is vulnerable to UV degradation. Without some type of protective coating it will crack, allowing water to penetrate. This particular repair also caused additional problems that will need to be addressed. Ultimately it will cause the eventual repair to the chimney to be more expensive than it would have otherwise been. There is also increased damage to the interior of the house.