Flat Roof Leaks in Monsoon Season

Flat and low-slope roofs were cheap to build and suited the dry climate, so many Maryvale ranch homes have them. Some use built-up layers of tar and gravel, some use roll roofing, and many have been covered with spray polyurethane foam, which insulates well and sheds water when its coating is intact. They work fine most of the year. The trouble comes when a lot of rain falls fast and has to get off a nearly level surface.

Flat roofs drain through scuppers, openings in the parapet wall, or through roof drains. When leaves, gravel or debris block them, water ponds. Ponding water finds any crack in the tar or foam, any lifted seam and any gap around a vent, pipe or cooler stand. Wind-driven rain can also push water under flashing where the roof meets a wall. Once inside, it soaks insulation and shows up as a ceiling stain, often some distance from where it entered.

Spray foam is protected by an elastomeric coating that blocks the sun. Over years, sun and heat wear the coating thin. Exposed foam turns brown, gets brittle and lets water in. Most foam roofs need recoating every several years depending on the product and exposure. If your foam looks chalky, brown or pitted, ask a roofer about recoating before the storms.

In May or early June, have the roof looked at. Clear scuppers and drains, remove debris, and check the seams and the area around the cooler and vents. Trim branches that hang over the roof. Inside, look at ceilings for old stains so you can tell if a new one appears. Keep a tarp, buckets and towels where you can find them.

If water starts dripping, put a bucket under it and move belongings away. If the ceiling bulges, poke a small hole at the lowest point over a bucket to let the water out in a controlled way; this prevents a larger section from falling. Turn off light fixtures that are wet at the breaker. Do not go on the roof during the storm.

Once it is safe, look at the roof from the ground or a ladder for debris, washed-off gravel, torn flashing and ponding. Photograph damage with the date visible. Call a licensed roofer for repairs and a restoration company to dry the inside. Drying should start right away, even if the roof repair takes a few days; ask the roofer for a temporary patch.

A small stain can hide a large wet area of insulation above. Wet insulation is heavy, loses its value and can grow mold, so it is often removed. Ceiling drywall that sagged or stayed wet long is usually replaced. A provider with a moisture meter can show how far the water spread before anything is cut. See flat roof leak damage.

Evaporative coolers add their own water to the roof. A stuck float or rusted pan can keep water running toward the cooler opening for days. Check the cooler monthly in season and look for stains near its vent inside.

Policies usually cover sudden storm damage, such as wind tearing part of the roof, but often exclude leaks from an old or poorly maintained roof. Photos, the storm date and a roofer's written note on the cause help your claim.

Older built-up roofs with a gravel top layer can lose gravel in heavy rain and wind, exposing the tar to sun. Bare spots crack and leak. After big storms, look for gravel piled at scuppers or washed onto the ground.

For the roof, call a licensed roofer. For water inside, call (623) 269-8054 to reach a local restoration provider who can start drying the same day.

Many flat roofs are surrounded by short parapet walls. Water can enter through cracks in the stucco on top of the parapet or where the roof meets the wall. A roofer should check the caps and flashing as part of a pre-season inspection.

Clear drains are the cheapest roof insurance.

Keep scuppers and drains clear, keep foam coatings fresh, check around the cooler and inspect before June 15. When a leak starts, catch the water, protect the ceiling, and start drying the same day.

Questions about flat roof leaks in monsoon season? Call (623) 269-8054 to reach a local Maryvale provider, 24 hours a day.