Your roof is supposed to form a protective membrane against moisture, which means the water should quickly drain off and away from your home. Unfortunately, moisture can sometimes pool on the roof, resulting in a major problem. The following are a few reasons why moisture pooling occurs along with tips on how to prevent the problem.
Issue #1: Clogged gutters
Dirty gutters or clogged downspouts can lead to moisture collecting on the roof instead of running off properly. This is more likely to occur on roofs with a minimal slope, since steep slopes will still shed water regardless of the gutter condition. The simplest way to deal with the problem is clean out the gutters and downspouts each spring and fall.
Issue #2: Damaged flashing
Flashing, especially that installed in a valley in the roof, can sometimes get bent or damaged by wind or hail. It then forms a dam that blocks water from draining down the roof valley as it is supposed to. After major storms, take a few minutes to survey the roof for damage. Have flashing repaired immediately if you find a problem, since the issues caused by pooling water will end up being much more expensive than simply fixing the flashing.
Issue #3: Roof debris
Although more likely to collect in a roof valley, debris can pile up on the roof anywhere. Leaves, sticks, and pine needles are the biggest offenders. These piles form dams that won't allow water to flow off the roof properly. Use a hose or a roof rake to force the debris off the roof whenever you notice it building up.
Issue #4: Cladding damage
Sometimes pooling occurs because the roof doesn't have an even slope because a depression has formed. The most common cause is damage to the plywood cladding beneath the shingles. This could be an area of rot from a leak, or an area that was damaged due to blunt trauma, such as from a falling branch. A roofer, such as Pro-Tech Contracting Inc., will need to remove the shingles and replace the damaged cladding before reshingling the area.
It's vital that water pooling is addressed as soon as possible. Water sitting on the roof will eventually find its way beneath the shingles, leading to an internal leak in your home. You will then have both a major interior and exterior repair to contend with. Contact a roofer in your area to schedule an inspection and repair.