What this video covers

Juan Curling walks a McAllen roof that leaks every time it rains hard, and shows the cause we find more than any other: nails driven in the wrong place. He finds exposed nail heads one after another, pulls one out of the shingle on camera, and explains why a roof installed this way can look perfect from the street for years.

• 0:35 The nail that causes the leak: how a single fastener in the wrong spot lets water into the deck.
• 1:16 Finding the exposed nails: lifting shingle tabs in the valley, where water accumulates and runs straight down behind the nail.
• 2:04 Pull-through: the wood expands and contracts with Valley heat and moisture until the nail backs out — Juan pulls one out by hand.
• 2:23 Why nobody notices: a bad installation looks the same as a good one from the driveway, so the roofer keeps getting referred down the street.
• 3:12 What to do if you have a leak: call a certified roofer, have them come at the right time of day, and look for the one hidden nail.
• 4:01 Pipe boots and flashing: why a dried, cracked rubber boot only lasts five or six years here, and what happens to the wood underneath it.
• 5:46 What we check first: exposed nail heads, then the underlayment — black felt tears around a nail, quality synthetic underlayment moves with the wood and keeps the seal.

Key takeaways

• One exposed nail head in a valley is enough to soak a ceiling in a heavy rain.
• Nails driven too high or over-driven work loose over time. That is called pull-through.
• A bad install is invisible from the street, which is how a whole neighborhood ends up with the same problem.
• Rubber pipe boots dry out fast in the Rio Grande Valley. Expect five to six years, not fifteen.
• Water running down the outside of a pipe rots the decking around it — often long before you see a stain on the ceiling.
• Underlayment matters: black felt paper tears around a nail; a higher-end synthetic expands and contracts with the wood and keeps the nail sealed.

Frequently asked questions

My roof only leaks in heavy rain. Is that still a problem?

Yes. It usually means water is getting past a small opening — an exposed nail, a cracked pipe boot, or failed flashing — and only reaches your ceiling when there is enough volume. The damage to the decking starts long before the drip appears.

How do you find a leak that small?

By getting on the roof and checking the places roofs actually fail: nail heads, valleys, pipe boots, vents and flashing. Often it is one nail. We photograph what we find and show you.

Can one nail really cause a leak?

Yes. Water accumulates in a valley, hits the exposed head, and runs behind it into the decking. If the underlayment is old felt, there is nothing left to stop it.

How long should a pipe boot last in McAllen?

The rubber ones give about five or six years in this heat. A lead boot will not rust, crack or corrode, and is what we prefer when it is installed and sealed correctly.

Do you charge for a roof inspection?

No. A roof inspection in McAllen is free, and about a third of the time the answer is that your roof is fine.

Read more: Why your roof leaks in McAllen — exposed nails, pull-through and pipe boots.

Think you have a leak?

Book a free inspection or call (956) 586-5711. We serve McAllen, Mission, Edinburg and the Rio Grande Valley. See our roof repair in McAllen and storm damage roof repair services, or read how roof insurance claims work.

Frontline Roofing — 601 N Main Street, Suite 102, McAllen, TX 78501