How to know if you should you patch or replace your roof

If you have a damaged or deteriorating roof, this advice should help you determine if what's in order is patching or reroofing. Make decisions with the long term in mind to save you money in the long run.

If a roof has been damaged by a falling branch, or if one small section is clearly in worse shape than the rest of the roof, patching may be a good solution. But if your roof is near the end of its life cycle (the roofer will tell you when you choose a roofing material what its life expectancy is), or if these symptoms appear over all the roof, you are wise to have it replaced.

• Remember: A leaky roof can cause expensive damage to your home's interior; it doesn't pay to take chances and hope that a worn-out roof will last another year or two.
• Get bids from at least two reputable roofing companies. Ask for recommendations from friends or neighbours who know the contractors' work. Lean toward local professionals who have been in business at least 10 years.

Asphalt shingle roofing is heavy; too many layers will cause undue stress on your roof's framing.

• Remember: In cold climates, the roof must support both the weight of the shingles and the weight of snow during winter.)

Most local building codes allow up to three layers of roofing and no more — check with your local building code department to be sure. If your roof already has three layers of shingles, all will need to be taken off before a new roof can be installed.

• To check how many shingle layers your roof has, look at the side edge of the roof — not the bottom edge, where an extra layer is sometimes applied. Lift up the shingles slightly and count the layers; don't count the roofing felt at the bottom.
• A "tear-off job" costs more than a simple reroofing job — a good argument for choosing the best, longest lasting shingles you can afford.
• The roofing company will need to place a dumpster very near your house so that they can shovel all the old roofing into it. Be sure that the contract for the reroofing spells out that the roofers will carefully clean up after themselves and will replace any landscaping or pavement that gets damaged in the process.

A sturdy roof is essential to protecting the interior of your house from the elements. Keep these tips in mind and contact a local contractor to help you determine which solution is right for your roof.