High-Nailed Shingles: How to Spot Them and Why They Blow Off
| # | Table of Contents |
|---|---|
| 1 | What Counts as High Nailing |
| 2 | Why Nail Placement Matters |
| 3 | How High Nailing Is Found |
| 4 | High Nailing and the Shingle Warranty |
| 5 | How It Is Fixed |
| 6 | How to Avoid It on a New Roof |
| 7 | FAQ |
What Counts as High Nailing
GAF's Technical Advisory Bulletin TAB-R-115 defines it plainly: "Shingles nailed too high above the butt (bottom) edge of the shingles or above nailing guideline are considered as high nailed shingles." Every shingle maker prints a nailing zone or nail line on the shingle and in the instructions. For example:
| Manufacturer document | Where the nails go |
|---|---|
| GAF Timberline installation instructions (2023) | Standard pattern of 4 nails about 6 7/8 inches from the bottom of the shingle, within a target zone of 5 13/16 to 7 5/8 inches; a 6-nail pattern is required for enhanced wind coverage on certain products |
| IKO laminated shingle instructions (Bulletin R-64) | 4 nails in the nail line 7 3/8 inches below the top edge; 6 nails in high-wind areas or on very steep slopes |
The building code sets the minimum underneath that: the manufacturer's required number of fasteners, "but not less than four fasteners per strip shingle" (IRC R905.2.6).
Why Nail Placement Matters
It can miss the double layer. A laminated (architectural) shingle is two layers bonded together, and they only overlap in a narrow band. GAF's bulletin says what matters most is that fasteners "penetrate through the double area at the nail line on laminated shingles." IKO's bulletin puts it in capitals: proper application "requires that the nails penetrate both the overlay and underlay portions of the shingle." A nail above that band holds only one layer, and the lower layer can separate from it.
It can break the seal. Shingles resist wind mainly by sealing to the course below. GAF warns that high nailing "can result in nailing through the self-seal strip, which unless the shingle is so designed, can adversely affect the shingle's ability to seal." An unsealed shingle can be lifted and creased by wind until it tears off.
It can miss the shingle below. IKO's bulletin on its 3-tab shingles says the specified nail location also ensures "the nail catches the top headlap edge of the shingle two courses below." Nails placed too high give up that extra hold.
Wind damage along the gable edge often has the same root cause. Our article on shingles blowing off at the rake edge covers the starter strip and drip edge side of that problem.
How High Nailing Is Found
You cannot see nail placement from the ground. Clues that point to it include:
- Shingles that blew off in a storm that was not unusually strong, especially on a newer roof.
- Shingles that lift or flap easily in wind, or that were never stuck down.
- Blown-off shingles in the yard with nail holes, or nails still in them, high up near the top edge.
- Where shingles are missing, nail heads sitting above the marked line on the exposed course.
Confirming it means lifting tabs and looking. That has a cost: GAF's bulletin notes that once a shingle is lifted, "the thermal seal was broken, and it will not reseal." Any shingle lifted to check nailing should be hand-sealed afterward.
High Nailing and the Shingle Warranty
Shingle warranties assume correct nailing. GAF's limited warranty says its wind coverage is "specifically conditioned on your shingles or ridge cap shingles being fastened and installed strictly in accordance with GAF's application instructions," and it excludes "improper fastening" when the improper installation caused the damage. It also notes that shingles that are "not fastened or installed properly may never seal."
In other words, wind damage traced to high nailing is an installation problem, not a manufacturing defect. That is a question for the contractor who installed the roof and their workmanship warranty, if they offered one.
How It Is Fixed
GAF's remedy is specific. Lift the shingles, add fasteners in the correct location, cover the high fastener with roofing cement, and hand-seal the shingle down. Where shingles have already blown off or creased, they are replaced and the surrounding shingles are checked and re-fastened.
When a few shingles in one area are high-nailed, re-fastening is a repair. When an inspection shows the whole roof was nailed high, every shingle would need to be lifted, re-nailed and hand-sealed, and at that point a roof replacement is often the more reliable answer.
How to Avoid It on a New Roof
- Ask which shingle line is being installed and whether it will be nailed with the manufacturer's standard or high-wind pattern.
- Ask whether the crew's nail guns are checked for depth and placement during the job.
- Ask to see a few installed courses before they are covered, or ask for photos.
- Read the manufacturer's warranty conditions so you know what installation it assumes.
Sources: GAF Technical Advisory Bulletin TAB-R-115, "High Nailing Shingles"; GAF Timberline installation instructions (RESTL622-PDF-0423); GAF Shingle and Accessory Limited Warranty (RESWT160L-0426); IKO Residential Information Bulletin R-64, "Proper Nailing for Laminated Shingles" (June 2008); International Residential Code (2024) R905.2.6.
Frequently Asked Questions
What does high nailed shingles mean?
It means the nails were driven above the manufacturer’s nail line. On laminated shingles they can miss the double-layer area, and they can go through the sealant strip so the shingle does not seal down.
Can high nailed shingles be fixed?
Yes. GAF’s bulletin calls for lifting the shingle, re-fastening in the correct location, covering the high nail with roofing cement and hand-sealing. If the whole roof is high-nailed, replacement is often more practical.
Does high nailing void the shingle warranty?
GAF’s warranty conditions its wind coverage on installation per its instructions and excludes damage caused by improper fastening. The warranty stays in place for manufacturing defects, but high-nailing damage is an installation issue.
How many nails should each shingle have?
The IRC requires the manufacturer’s number and never fewer than four per strip shingle. Many laminated shingles call for four in standard areas and six for high-wind or enhanced wind coverage.
Can a home inspector see high nailing?
Only by lifting shingle tabs, which breaks the seal. Any shingles lifted to check should be hand-sealed afterward.
