Installation Standard
The Roof Shepherd Installation Standard
Every shingle maker publishes its own installation rules, and the building code sets the floor. We compared seven makers and the code side by side, and on nearly every topic the roofs we oversee are held to the strictest one. Where we chose differently, the row says so.
Updated September 27, 2026
The Rule
The strictest source wins
For each part of the roof, we read what the building code requires, what each of seven shingle makers requires, and what the industry's technical bodies recommend. Our line is the strictest of them, with one stated exception: sound wall flashing is reused unless the shingle maker or the warranty requires new. The installed product's own instructions still apply in full on top of it.
Stricter than the makers, on purpose
A few of our lines are stricter than the makers' standard application, on purpose: six nails in every field shingle on every roof, where the makers call for six only in high wind or steep areas; no visible nail at completion; and metal on every vent, cap and pipe flashing in our scope.
At completion, the installing crew's lead and a Roof Shepherd supervisor check every slope together, on foot where it is safe and by photo where it is not, and initial a checklist built from this standard. Anything that fails is fixed before we call the job complete, and the homeowner receives a copy.
Line by Line
Our line, the code, and the strictest source
| Topic | Our standard | Building code minimum | Strictest manufacturer or industry source | Explained |
|---|---|---|---|---|
| Nails | Six nails per shingle, 1-1/4 inch minimum, no staples | 12 gauge shank, 3/8 inch head, 3/4 inch into the deck (IRC R905.2.5) | Through the deck by at least 1/4 inch (Owens Corning); 1-1/4 inch minimum length (Atlas); no staples (most makers) | Learn why |
| Nail pops | At completion, no nail head is visible or raised. Raised nails are driven flush or pulled, sealed and renailed. The only exposed heads are the ones the maker requires, such as the last ridge cap, and they are covered with roofing cement | Not addressed | Never visible on the finished roof (ARMA, CertainTeed, Atlas) | Learn why |
| Drip edge | Every eave and rake, 2 inch laps, nails every 8 to 10 inches | Eaves and rakes, 2 inch laps, nailed 12 inches apart (IRC R905.2.8.5) | Nailed every 8 to 10 inches (GAF) | Learn why |
| Underlayment | 6 inch end laps staggered 6 feet, plastic cap nails | 2 inch side laps, 4 inch end laps (IRC R905.1.1) | 6 inch end laps (Malarkey, CertainTeed, Atlas); cap nails (GAF) | Learn why |
| Low slopes | Any face from 2:12 to under 4:12 gets two layers of underlayment or a full self-adhered membrane; no shingles go on a face flatter than 2:12 | Double underlayment from 2:12 to 4:12; no shingles under 2:12 (IRC R905.2.2) | Double underlayment or a full self-adhered membrane | Learn why |
| Valleys | Ice and water in every valley first. Where the valley is open metal, the metal is at least 24 inches wide and 24 gauge | 24 inches wide, 26 gauge (IRC R905.2.8.2) | 24 gauge on its roofs (GAF) | Learn why |
| Nails near valleys | None within 6 inches of the valley center | Not addressed | None within 6 inches of the valley center (GAF, CertainTeed, Atlas, TAMKO) | Learn why |
| Starter | The maker's own starter at every eave and every rake | Not addressed | The maker's own starter at eaves and rakes, tied to their wind coverage (GAF, Owens Corning, CertainTeed, Malarkey, TAMKO) | Learn why |
| Kick out flashing | Required at every one; a missing one gets installed | Required where an eave meets a sidewall (IRC R903.2.1) | Shown or optional | Learn why |
| Wall flashing | Reused when sound, replaced when it has failed or is missing; new throughout on premium warranty jobs | Replace when rusted, damaged or deteriorated (IRC R908.5) | Replace unless like new (CertainTeed); new for premium warranties | Learn why |
| Chimney crickets | A cricket behind any chimney 24 inches or wider, priced on your estimate | Chimneys more than 30 inches wide (IRC R903.2.2) | 24 inches or wider (NRCA); wider than 24 inches on steeper roofs (CertainTeed, GAF) | Learn why |
| Attic ventilation | To the applicable code; the vent plan is shown on your estimate | 1/150 or balanced 1/300 (IRC R806.2) | Never mix exhaust types over one attic (CertainTeed, Atlas, ARMA) | Learn why |
| Vents and pipe covers | Every vent, cap and pipe flashing in our scope is metal; no plastic flange or vent body in our scope is left exposed | Not addressed | No plastic flanges on premium jobs (Malarkey) | Learn why |
| Extra layers | Full tear off to the deck; any bonded membrane that cannot come off without ruining the deck is shown to you and handled as the code allows. Every hidden layer is photographed on its own | No layover on two or more layers (IRC R908) | Tear off for premium warranties | Learn why |
Beyond Our Standard
Stronger still: the IBHS FORTIFIED Roof™
The Insurance Institute for Business and Home Safety, the insurance industry's research group, publishes the FORTIFIED Home™ Standard. Its roof level goes well beyond our standard. The largest differences are a deck re-nailed with ring-shank nails 4 inches apart, a sealed roof deck (taped seams, a double underlayment, or a full peel-and-stick membrane), edge metal nailed every 4 inches with a sealed starter, wind-rated shingles, and all new flashing.
Who can build one, and what insurers give
A home earns the designation only after an independent evaluator documents the work, and since November 1, 2025 the roof must be installed by a certified FORTIFIED Roofing Company. The Roof Shepherd is not certified yet.
Texas law does not require an insurer to give a FORTIFIED discount, and the insurers that offer one set their own terms; the details, and the questions to ask your carrier in writing before paying for any upgrade, are in our insurance guide. How FORTIFIED works, layer by layer.
Sources: each manufacturer's current installation instructions and limited warranty (GAF, Owens Corning, CertainTeed, IKO, Malarkey, TAMKO, Atlas); International Residential Code 2021 and 2024, Chapter 9 and R806; ARMA technical bulletins on nail application (2018), attic ventilation (2023) and reroofing (2024); an NRCA reroofing article (2004); IBHS 2025 FORTIFIED Home™ Standard and Roofing Contractor Handbook v2025.1; Texas Department of Insurance Bulletin B-0008-26. FORTIFIED, FORTIFIED Home and FORTIFIED Roof are trademarks of the Insurance Institute for Business & Home Safety. The Roof Shepherd is not affiliated with or endorsed by IBHS.
Common Questions
Common questions about the installation standard
Which manufacturers were compared?
GAF, Owens Corning, CertainTeed, IKO, Malarkey, TAMKO and Atlas, using each maker's installation instructions and warranty as published when we checked, plus the 2021 and 2024 International Residential Code, the technical bulletins of the Asphalt Roofing Manufacturers Association and an NRCA reroofing article (2004). The comparison was done on September 27, 2026.
If the shingle on my roof has its own instructions, which one applies?
Both. The product's own instructions always apply in full. This standard only adds to them. Where a product is stricter than a line here, the product wins on that roof.
How is the standard checked on my roof?
At completion the installing crew's lead and a Roof Shepherd supervisor check every slope together, on foot where it is safe and by photo where it is not, and initial a printed checklist, line by line, starting with nail pops. Anything that fails is fixed before we call the job complete, and you receive a copy.
Is every piece of wall flashing replaced?
No. The code allows sound flashing to stay and requires replacement when it is rusted, damaged or deteriorated, unless the shingle maker's instructions call for new flashing, which the code then also requires (IRC R908.6). We follow that: flashing that has failed or is missing is replaced, and a maker or premium warranty that requires new flashing gets new flashing throughout.
Is The Roof Shepherd a certified FORTIFIED Roofing Company?
Not yet. Since November 1, 2025, only a certified FORTIFIED Roofing Company can install a roof that qualifies for the designation, and certification requires, among other things, two years in business. We will say so here the day that changes.
How often is this standard updated?
We review it at least once a year, and sooner when we learn a maker or a city has changed its rules. The date at the top of this page is the last review.
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