Living in Arizona means you enjoy over 300 days of sunshine a year. But when the clouds finally gather and the monsoon season hits, you have to be ready for torrential downpours that test the limits of your home’s exterior. During these intense storms, the last thing you want to hear is the drip of water hitting your living room floor.
While some leaks are obvious, others are insidious, causing rot behind the scenes for months before you notice a stain. We have compiled a list of possible reasons why your roof is leaking to help you troubleshoot the issue. By familiarizing yourself with these common failure points, you can become a more informed homeowner capable of asking the right questions when it’s time for repairs.
1. Cracked or Slipped Clay and Concrete Tiles
If you look around your neighborhood, you will likely see roofs covered in clay or concrete tiles. These durable materials are excellent for deflecting the desert sun, but they are not the primary waterproofing layer. Instead, tiles act as a watershed, shedding the bulk of the rain off the slope while protecting the delicate underlayment beneath. However, physical damage to these tiles instantly compromises that protection.
High winds, falling tree branches, and heavy hail can cause tiles to crack or slide out of position. Once a tile breaks or slips, the sun beats down directly on the underlayment, which dries it out and causes it to tear. Then, water slips past the tile shield and infiltrates your home.
2. Compromised Flashings
Roof penetrations are the most common entry points for water. Anywhere a pipe, vent, chimney, or wall intersects with the roofline, your roofer installs metal strips called flashing to seal the joint. These metal pieces direct water away from the vulnerable seams and down the roof slope. Over time, however, the sealant (mastic) used to adhere the flashing degrades due to sun exposure.
Additionally, metal expands and contracts with temperature changes, which works the flashing loose from the roofing material. Once the seal breaks at valleys, plumbing vents, skylights, or wall intersections, water gets a path inside.
And lastly, rust is another issue. Oxidized metal develops pinholes that allow moisture to seep through during heavy rains.
3. Thermal Shock and Splitting
The desert climate subjects your home to massive temperature swings. It is not uncommon for roof surface temperatures to reach 150 degrees Fahrenheit during the day and drop significantly at night. This rapid heating and cooling cycle causes roofing materials to expand and contract aggressively, a phenomenon we call thermal shock.
Over time, this constant movement fatigues the materials. Foam roofs may develop blisters, modified bitumen sheets can pull apart at the seams, and asphalt shingles might lose their granules. Eventually, the stress causes the material to split or tear. These splits might be invisible during dry weather, but as soon as rain falls, the material expands again, opening the crack and allowing water to enter.
4. Clogged Scuppers and Gutters
Proper drainage is essential for a healthy roof. On flat roofs, we use outlets called scuppers to direct water through the parapet walls and away from the building. Pitched roofs rely on gutters and downspouts. However, dust storms and local vegetation can fill these drainage channels with leaves, dirt, bird nests, and twigs.
When a scupper clogs, the roof becomes a bathtub. The water level rises until it finds a way in, usually through the flashing at the wall or even over the top of the roof edge. Similarly, clogged gutters force water to back up under the eaves and shingles, rotting the fascia boards and soaking the roof decking.
5. Dried-Out Skylight Seals
Skylights add beautiful natural light to a home, but they are notorious for leaking if not maintained. The unit relies on rubber gaskets and weather stripping to keep the glass or acrylic sealed against the frame. Unfortunately, the Arizona sun is brutal on rubber and plastic components.
As these seals dry rot and crack, the watertight bond fails. You might notice drips directly underneath the skylight during a storm. Furthermore, the flashing around the skylight curb (the raised box the skylight sits on) is a common failure point. If the metal flashing lifts or the sealant cracks, water runs down the curb and into the ceiling assembly.
6. Improper Solar Panel Installation
Arizona is the perfect state for solar energy, but the installation process puts your roof at risk for leaks. Why? Installing panels requires bolting racking systems directly through the roofing material and into the trusses. Each bolt creates a new hole in your roof. If the installers miss the rafter or fail to seal the penetrations correctly, you could have leaks.
7. Bird and Pest Activity
Local wildlife seeks shelter from the heat just like we do, and that protection is often found near residential roofs. Pigeons are particularly destructive to roofs. Their droppings are acidic and eat through roofing materials. Granted, this takes a long time. But they also love to peck at polyurethane foam roofs, creating divots and holes where water accumulates.
Likewise, rodents and birds also build nests in tight corners, under solar panels, inside vents, and within scuppers. These nests block water flow, causing backups and leaks. You should install bird stops at the eaves of tile roofs and mesh screens around solar panels to keep these pests from turning your roof into their home.
Protect Your Investment With Arrow Roofing
Now that you know possible reasons why your roof is leaking, you can turn your stress into action. Once you know or suspect you have a leak, do some investigating to locate the cause. And then make sure you call in the pros.
At Arrow Roofing, we provide a full range of solutions, including emergency patch-ups, tile replacements, foam recoating, and complete restorations. We understand the specific challenges the Arizona climate presents and use high-quality materials to ensure your home stays dry. Don’t wait for the next monsoon to test your luck. Contact us today for reliable roof repair services and get the peace of mind you deserve.