A leaky roof can be a bigger problem than just needing new roof. Roof leaks can cause damage the roof boards, ceilings, walls, floors, and more. Letting the leak continue will only exacerbate the problem causing the roof repair to be even more costly. Common causes for leaky roofs include:


The most common cause of roof leaks is age. As roofing materials age they deteriorate and eventually they will leak unless replaced. Exposure to sunlight and winter snow and temperatures can cause shingles to get brittle and crack over time. Luckily technology has improved roofing materials making today’s roofs more durable than roof materials of fifty years ago.


Build up of twigs, leaves or other material can cause water to back up under shingles causing leaks. Keeping valleys and gutters clean will help to prevent roof leaks. Keeping tree branches away from the roof will eliminate some debris build up.


When a TV antenna or other roof mounted installation is removed holes can allow water to leak into the house. When removing anything that has made holes in the roof be sure to seal the holes.

Missing Shingles

Shingles that are damaged by wind or weather can become lose and allow water to enter under the surrounding shingles. Roofs should be inspected periodically to check for missing or damaged shingles.

Ridge Caps

Ridge caps cover the peak of the roof to prevent water from leaking into the gap where the two sides meet. Improperly installed ridge caps or ridge caps that are damaged can allow rain water to seep under the shingles.

Roof Vents

When roof vents are installed they must be installed and properly sealed to prevent them from leaking. Gaskets around vents as well as plastic vents need to be inspected to be sure they aren’t cracked or damaged after being exposed to varying weather conditions.


If the pitch of the roof isn’t steep enough, shingles can be lifted by strong winds. Pitch is measured as a ratio of its vertical rise, in inches, over a horizontal distance of 12 inches. The International Building Code stipulates that the roof slope must be at least 2:12 for installation of asphalt shingles. If the slope is between 2:12 and 4:12, a double layer of underlay material must be used. Roofing materials must be appropriate for the roof pitch and be installed properly to prevent leaks.

Water Backup

Clogged gutters or eavestroughs can cause water to backflow under the roofing materials and leak into the home. Installing gutter guards will keep the gutters clean and present backflow of water.

The roofing professionals at iRoofing Toronto are trained to inspect roofs for damage that can cause leaks. We recommend periodic inspections be scheduled to check the integrity of your roof.

Call us at (416) 477-1070 today to make an appointment to get your roof inspected or for an estimate for replacement or repair of a leaky roof.