Keeping your roof clean can avoid some possible leak problems. After the snow and ice have melted from your roof and gutters, it's a good time to inspect the roof and remove accumulated leaf debris. If leaves and twigs accumulate around attic vents and at the bottom of valleys, that will eventually block the free flow of water around the vents and in the valleys. This often results in a leak into the house if you have a good rainfall.
In a steady rain, a lot of water flows in the valleys. The bottom 4 feet of the valleys is where leaves and twigs tend to accumulate. This build up of debris acts like a dam that will cause the water to back up. As the water backs up and gets deeper in back of this dam, it will go between the rows of shingles and find a way into the house. Remember that a shingled roof is designed to shed freely flowing water. It won't keep out standing water like a rubber membrane roof.
Clean around the attic vents too. The same back up can occur around a vent. On the sides of the vent, it takes very little debris build up to cause the same kind of back up, with water getting under the flange of the vent and into the house.
Monday, January 28, 2013
After 30 or 40 years, the galvanized steel flashing around a brick chimney will start rusting away and should be replaced. If the chimney needs to be torn down to the roof line, the mason should replace the flashing as originally installed. If no tear down is needed and the bricks are sound, the most permanent and waterproof method involves cutting off the old flashing, adding galvanized step flashing at each row of shingles and installing a riglet counter flashing to cover the tops of the step flashing. A 3/4″ deep groove is cut into the bricks to receive the bent edge of the riglet. A bead of flexible caulking seals between the top of the riglet and the brick.