Green streaks, fuzzy moss, and piles of leaves on a roof worry many homeowners. Some of it is cosmetic. Some of it can lead to leaks over time. Knowing the difference helps you decide what to do. Algae Dark streaks on shingles are usually algae. They tend to show up on shady, damp roofs. Algae
Moss, Algae, and Debris on Your Roof: Do They Cause Leaks? Read More »
Every bolt or screw that goes through a roof makes a hole. Solar panel mounts, satellite dishes, antennas, and rooftop equipment all need to be attached, and each attachment has to be sealed. When the sealing is done well, it can hold for years. When it is not, the roof starts to leak. How these
Leaks After Solar Panels, Satellite Dishes, or Antennas Are Installed Read More »
Most leaks do not begin in the middle of a clear slope. They begin at a joint, and one of the most common joints is where a roof meets a wall. That includes dormers, second-story walls that rise out of a lower roof, and additions built onto an older house. Why these joints leak The
Leaks Around Dormers, Additions, and Roof-to-Wall Joints Read More »
An attic that cannot breathe holds heat in summer and moisture in winter. Both can hurt the roof. Some problems that look like roof leaks are actually ventilation problems, and some real leaks get worse because of poor airflow. What ventilation does A ventilated attic has air coming in low, usually through vents under the
Attic Ventilation and Roof Leaks: What Poor Airflow Can Do Read More »
Gutters look like an add-on, but they are part of how the roof sheds water. When they work, water leaves the roof edge and goes down and away from the house. When they clog, that water has nowhere to go. How a clogged gutter becomes a roof leak A gutter packed with leaves and debris
How Clogged Gutters Cause Roof Leaks Read More »
A valley is the channel where two roof slopes meet at an inward angle. Rain and snowmelt from both slopes run into it, so it carries more water than any other part of the roof. A small flaw that would never matter on an open slope can leak badly here. Two ways valleys are built
Roof Valley Leaks: Why the Low Spots Fail First Read More »
A chimney is a column of brick sitting on a sloped roof, and water reaches it from every direction. It runs down the roof into the uphill side, falls on the top, and soaks into the masonry. A leak that looks like a roof problem may be coming from any one of several parts. The
Why Chimneys Leak Where They Meet the Roof Read More »
Shingles shed water on open slopes. Flashing handles the places where a slope ends or something pokes through it. It is the thin metal, usually steel or aluminum, that lines the edges of chimneys, skylights, walls, valleys, and vents. When flashing fails, water gets behind the shingles at exactly the spots that take the most
Failed Roof Flashing: One of the Most Common Places Roofs Leak Read More »
