Is your roof leaking?
Waterproof Under the Shingles
If you are replacing an old roof or working on new construction, you will need to know how to waterproof your roof from the start. Shingles are the most common roofing material, and all shingle roofs should have a solid waterproof material, such as tar paper or roofing felt, between the rafters and shingles. A newer, lighter and stronger option for waterproofing your roof under the shingles is thermoplastic polyolefin. There are also breathable TPO membranes that allow water vapour to pass through. This may not seem to be how to waterproof your roof, but the permeability actually reduces condensation in the attic
Waterproof Over the Shingles
If wood shingles are getting old enough to show wear but not old enough to replace, here’s how to waterproof your roof and get a few more years of use out of the shingles. Spray, roll or brush a waterproofing compound directly on to the shingles. The oil- or water-based compounds basically restore the original waterproofing oils and resins in shingles. Oil-based compounds tend to last longer, but the water-based compounds are more environmentally sound. Of course, these compounds will not help waterproof your roof if you don’t have a waterproof underlayment, as discussed in the first part of this roof waterproofing manual on how to waterproof under the shingles.
Check the Shingles and Flashing
The most important part of this roof waterproofing manual regards troubleshooting and checking over the roof. A waterproof underlayment can’t stop leaks through the flashing, and a waterproof coating can’t keep broken shingles from leaking. Look all over the roof for damaged, loose or missing shingles. Gaps in the shingles can leave the underlayment exposed to wind and sun, which can rapidly deteriorate the underlayment. Next, check the flashing, another name for the metal seals between the roof and the chimney, vents or skylights. Seal or replace any flashing that has gaps, cracks or holes. Some experts say the flashing causes 90 percent of roof leaks, so without checking the flashing, you won’t know how to waterproof your roof and prevent leaks.
Picture Cred: Tom Curry Roofing; Article Source: networx