Avoiding Water Intrusion Issues with Steep and Flat Roofs

SOUTH SAN FRANCISCO — While water intrusion is a concern with any roof, different roof styles present different areas of concern. Here are two prevalent roof styles and the water intrusion issues commonly associated with them.

Steep roofs
Roofing contractors will often espouse the quality of a particular type of shingle, but when it comes to waterproofing a steep roof, it’s what’s beneath the shingle that matters most. Due to a steep roof’s configuration, components like flashings, underlayment and leak barriers are vital in protecting against water intrusion. While proper installation of these components can maximize a roof’s lifespan, when roofers cut corners with waterproofing, problems can begin to arise.

One common scenario is when a roofer replaces a roof’s shingles but neglects to replace flashings and underlayment, which often results in premature leaks. Likewise, citing the moderate Bay Area weather, roofers often neglect to install leak barriers in areas like valleys, skylights, chimneys and roof-to-wall transitions. However, while the local weather conditions aren’t as harsh as in other areas of the country, elements such as wind-driven rain can still lead to water intrusion issues in Bay Area homes that don’t have this added protection.

Flat roofs
Due to the superior technology used to waterproof flat roofs, flashings and other steep roof waterproofing components typically aren’t applicable. However, there’s another water-related concern when it comes to flat roofs: the home’s drainage system.

The drainage system of a flat roof home often consists of a single drain that goes through a principal wall and into a downspout, which channels all water that falls on the roof. If this drain gets clogged, it can cause water to back up and overflow inside the home. Even worse, it can create a weight issue on top of the roof and potentially lead to a structural collapse. So, if you have a flat roof, make sure you’re proactive about cleaning your gutters and drains.