Leaky Valleys
First and foremost is the valleys. If you roof is more than 10 years old than more than likely you do not have Ice and Water Shield in the valleys. The Ice and Water shield is a synthetic underlayment that help prevent ice damning and deterioration of your decking. I know that in Illinois for instance it is code for all houses to have it in all vallleys and 24″ up from any interior walls.
The easiest way to fix this kind of leak is to tear up all of the shingles in the valley and repair any damaged plywood decking, first. Next you should put down your ice and water shield. After that either install your metal valleys and then shingles or just install new shingles.
What about my chimney?
If your chimney is leaking it cold be a couple of different things. If you have a brick or stone chimney than I would first check your counter flashing. Counter flashing is the metal betweent he shingles and the chimney. After time usually the caulk used to seal around the base of the chimney wears down and the metal will tend to fold away from the chimney. This creates an opening for watre to get through.
If you have a chimney chase or chimney that has vinyl or metal siding on it than you have a problem underneath your siding. The installers of the siding are supposed to run ice and water shield up all walls. If this was never done than there is no way around it. You must pull of the siding to about 24″-36″. Remove the shingles closest to the chimney. Install ice and water sheild so that it runs up the wall of the chimney, I would say 24″ up and then the remaining 12″ will go under the shingles you already removed.
Rubber or plastic plumbing boots.
These are at the base of the PVC pipes that run out of the roof to vent your water waste. The rubber or plastic boots have a really big problem with cracking after over exposure to the elements. The best thing to do when you go to replace these is to use a lead boot instead of the plastic one. The lead boot is virtually indestructible and will last much longer.
Getting the job done right
I recommend using a local contractor that is very well established. This way you know that they are going to back up their work. Anybody can pretend to know what they are doing when do even the simplest of things on a roof. Make sure that you get an estimate in writing with the job scope or else you might just be paying somebody to pretend like they are working. They know that the average person is not going to climb around on their roof to check the work that they just paid for. Always look for the BBB logo.
