What causes nail pops on a roof, and what to ask for

What causes nail pops on a roof?

Mostly heat and cold. Day and night temperature swings make the roof deck expand and shrink, and that slowly works roofing nails loose. Isolated nail pops on a roof that is otherwise sound are usually a repair, not a new roof. Ask for a roofer's written bid that counts the pops and checks the wood deck under them.

Key takeaways

• The right fix pulls the nail and fastens the shingle in a new spot. Hammering the old nail back down doesn't restore its grip.
• Pops across several slopes, or on a roof only a few years old, usually point to a problem with the whole roof.
• A leak from wear and tear is usually not covered by homeowners insurance, so price the repair now.

What is a nail pop, and what else causes it?

A nail pop is a roofing nail that has backed partway out of the deck. It pushes up on the shingle above it, so you see a small bump or a lifted tab.

Temperature swings are the main driver, according to a roof inspection firm that works for insurance adjusters. It adds four more causes: nails driven crooked or not flush, nails too short or with smooth shanks, poor attic ventilation, and rust. A Central Texas roofer says installation error is the most common cause on roofs less than ten years old.

Are nail pops on a roof serious?

Serious enough to fix. A pop is not a leak yet, but left alone it can become one. The home inspectors' trade group, the International Association of Certified Home Inspectors (InterNACHI), says nails that aren't driven flush "protrude and, over time, will wear a hole in the overlying shingle."

The lifted shingle also loses its seal. Wind-driven rain can then get under it and reach the deck. That water can travel across the wood and sit for weeks before a stain shows inside, per the Central Texas roofer. A Lancaster County, Pennsylvania roofer adds that a rusty nail means moisture has been reaching the metal.

The Central Texas roofer says the pattern matters more than the count:

• One or two pops on an aging roof are not unusual. That's a repair line.
• Pops in regular rows along the nail lines suggest the roof was nailed wrong from the start.
• Pops on a roof only a few years old point to installation defects rather than age.
• Pops next to a ceiling stain may mean water has already gotten in.

If the report shows a stain or wet decking, get a roofer out before your deadline. Don't climb up to look yourself. The Pennsylvania roofer says a sloped roof "creates a serious fall risk."

How do you fix a nail pop?

The roofer lifts the shingle and pulls the popped nail. They check the deck for soft or rotted wood, then drive a new nail in a fresh spot. A cracked shingle, or one that no longer seals, gets replaced.

Driving the old nail back down doesn't work. The Central Texas roofer says the wood has already lost its grip, so hammering it "typically accelerates the next failure at the same location."

The new nails have to go in right. InterNACHI says a typical 3-tab or laminate shingle takes four nails spaced evenly across it. Each nail should reach at least 3/4 inch into the deck. Ask the roofer to say in the bid that the new nails meet the shingle maker's placement.

The Central Texas roofer says most of these repairs take one visit of one to two hours. If the deck no longer holds nails, the job grows into deck repair.

What does roof nail pop repair cost?

One roofer in Lancaster County, Pennsylvania, publishes its prices for this work. Your area will differ, so use these to see how scope moves the price, then get your own bid.

Source: Joyland Roofing roof repair pricing, local, Lancaster County, Pennsylvania.

Kept prices every line of an inspection report for $79, usually under 4 hours.

The roofer says the nail-pop range assumes the problem is limited, easy to reach, and needs no significant shingle or deck replacement. Pops spread over a larger area, a steep roof, brittle shingles, or a valley can raise it.

Here is how it adds up. Say your report lists popped nails and a few missing shingles on the same slope. At this price list, that's $200 + $450 = $650 at the low end and $400 + $700 = $1,100 at the high end. A roofer doing both on one visit may price them together, so ask for one combined bid. If the roofer finds rotted plywood under the pops, the deck line is priced on top.

When pops are widespread and the shingles are near the end of their life, the Pennsylvania roofer says replacement may be the more practical option. That's a different ask. Weigh it with the other roof findings on your inspection report.

What should I ask the seller for?

Ask for the repair before closing, or a credit equal to the roofer's written bid. Name the scope and the trade. For example: remove popped nails and refasten in new locations on the rear slope, check the deck at each pop, replace cracked shingles, by a licensed roofer, per the attached bid.

Ask the roofer to put three things in the bid:

• How many pops they found, and on which slopes.
• Whether the deck under them is sound.
• Whether the pattern points to the whole roof.

To get that bid inside your window, see how to get repair estimates during the inspection period. What to ask for after a home inspection shows how this line fits with the rest of your list. The buyer repair request letter template has the wording around it.

If the seller does the work, ask for the roofer's invoice showing what was replaced.

What if the seller says no?

You have three choices. Pay a roofer after closing, ask for a smaller credit, or cancel if your inspection contingency is still open. A handful of dry pops is a small, known cost. Rows of pops or a wet deck is a bigger decision, so get the roofer's view before you choose. Your contract sets the exact dates and terms, so confirm them with your agent.

Are roof nail pops covered by insurance?

Don't count on it. Progressive says that if a roof leak "is due to lack of maintenance or wear and tear, homeowners insurance typically won't cover it." In Texas, the state insurance department warns that your insurer will inspect the roof when you apply and may charge more or refuse coverage based on what it sees.

Are roof nail pops common?

Yes. The adjusters' inspection firm calls them a common issue on asphalt shingle roofs, especially aging ones. Common doesn't mean harmless, which is why the pattern matters.

How do I know what my whole list is worth?

If nail pops are one finding among many, upload your inspection report to Kept and spend your remaining days on the roofer's bid.

Sources

• Knight's Solutions, A Claims Adjuster's Guide to Roof Nail Pops
• Cupcake Home Improvements, Nail Pops on Roof: Causes, Risks, and How to Fix Them
• Joyland Roofing, What Causes Roof Nail Pops? A Real Repair in Landisville, PA
• Joyland Roofing, Roof Repair Cost
• InterNACHI, Mastering Roof Inspections: Asphalt Composition Shingles, Part 26
• Progressive, Does homeowners insurance cover roof leaks?
• Texas Department of Insurance, Insurance and your roof