The short answer
Nail pops are fasteners that have backed out of the decking and pushed up under the shingle above, showing as small raised bumps, often in rows. Each popped nail is a potential leak path once it works through the shingle. They are inexpensive to correct and they are a classic finding on roofs between years five and fifteen.
What causes it
| Cause | How you can tell | How common |
|---|---|---|
| Thermal cycling of the deck | Rows of bumps, roof is 5 to 15 years old | Most common |
| Nails missed the rafter | Clustered pops in a line | Install issue |
| Overdriven or underdriven nails | Widespread, young roof | Install defect |
| Decking moisture movement | Pops with other moisture signs | Ventilation |
| Wrong fastener length | Early widespread popping | Warranty question |
How fast do you need to act
Not urgent, but worth correcting at the next service visit. Each pop eventually works a hole through the shingle above it, and a roof with many pops leaks in many small places at once.
What to do right now
- From the ground with binoculars, look for regular rows of small bumps
- Check the attic for nail tips that have backed out of the rafters
- Note the roof's age, because widespread pops on a young roof is an install problem
- Have them properly sealed and refastened rather than just hammered back
- If the roof is young and under warranty, get the installer back
What we see in the Hill Country
The daily thermal swing here drives this harder than in milder climates. A deck that expands and contracts through forty-plus degrees every day for a decade works fasteners loose, and we find nail pops on a large share of Hill Country roofs at the ten-year mark.
When to call us
We inspect for this at no charge across Boerne, San Antonio, New Braunfels, Kerrville, Fair Oaks Ranch, Bulverde, Helotes, Spring Branch, Austin and Stone Oak. You get photographs of what we find and a written explanation, including when the honest answer is that nothing needs doing yet. Call (210) 245-4125 or book an inspection.
