When repair is no longer the right answer, we replace the complete roofing system to code and manufacturer requirements, with materials suited to North Texas hail and heat. American Prime General Construction is a veteran-led roofing and general contractor in Richardson, and roofing is our primary trade.
This page sets out what a correct, code-compliant replacement includes, from tear-off and decking through underlayment, edge metal, nailing, ventilation, and cleanup. If your roof does not need all of that, we will quote a roof repair instead.
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Tear-Off to the Deck: What a Full Replacement Includes
- Complete tear-off to the deck and decking evaluation
- Underlayment, leak barrier, flashing, and ventilation components
- Shingle options including impact-resistant classes
- Code-required items and manufacturer specifications
- Site protection, magnet sweep cleanup, and final walkthrough
The 2021 International Residential Code defines roof replacement as removal of existing layers of roof coverings down to the roof deck. A recover, meaning new shingles over the old ones, is not permitted under Section R908.3.1.1 where the existing covering is water soaked or deteriorated below an adequate base, where it is slate, clay, cement, or asbestos-cement tile, or where the roof already has two or more layers of any covering.
We tear off for practical reasons too: you cannot inspect decking you have covered, and flashing has to be rebuilt rather than shimmed. Impact-resistant products can also require it. CertainTeed states that for Class 4 impact resistance its impact-rated shingles must be applied in a new roof or tear-off application, and not by roofing over existing shingles.
Decking Inspection, Replacement and Re-Nailing
Asphalt shingles must be fastened to solidly sheathed decks, so once the roof is stripped we walk every plane and replace sheathing that is delaminated, rotted, or too thin to hold a fastener. GAF specifies a minimum 3/8-inch plywood or OSB deck in its Timberline application instructions, and fasteners must penetrate not less than 3/4 inch into the sheathing.
Re-nailing the deck is a resilience upgrade available only while it is exposed. The IBHS FORTIFIED re-roof standard calls for re-nailing the roof deck with 8d ring-shank nails at 6 inches on center, and 4 inches on center at gable ends, at least 0.113 inch in diameter and 2 3/8 inches long.
Underlayment, Leak Barrier and Valleys
Underlayment is not interchangeable. The code requires underlayment for asphalt shingles to comply with listed standards and bear a label showing it, naming ASTM D226 Type I or II, ASTM D4869, and ASTM D6757. Traditional 15 and 30 pound felts are the D226 and D4869 products; synthetics qualify by being recognized as equivalent to those standards, which is how the IBHS re-roof standard describes an acceptable synthetic. We use synthetic on most replacements because it lies flatter and holds up better before the shingles go on.
At valleys and penetrations we install self-adhered membrane rather than felt. For a closed-cut valley the code permits a self-adhering polymer-modified bitumen underlayment complying with ASTM D1970 in lieu of the valley lining material, and an open metal valley lining must be not less than 24 inches wide. That membrane, commonly called ice-and-water shield, seals around fasteners.
Drip Edge, Starter Strip and Edge Details
Under 2021 IRC Section R905.2.8.5, drip edge is required at eaves and rake edges of shingle roofs:
| Requirement | 2021 IRC R905.2.8.5 |
|---|---|
| Lap at adjacent segments | Not less than 2 inches |
| Projection below sheathing | Not less than 1/4 inch |
| Extension back onto the deck | Not less than 2 inches |
| Fastening | Mechanically fastened to the deck at not more than 12 inches on center |
| Sequence at eaves | Underlayment installed over the drip edge |
| Sequence at rakes | Underlayment installed under the drip edge |
Starter strip is the other edge detail crews skip. Purpose-made starter puts the sealant band at the eave and rake so the first course is bonded down, and GAF states that maximum wind speed coverage applies only with starter strip products installed at the eaves and rakes.
Nailing Patterns and Wind Coverage
The code floor is not less than four fasteners per strip shingle, plus whatever the manufacturer requires. GAF describes a standard pattern of four nails placed in the nailing area and an enhanced pattern of six nails in the same zone, noting the enhanced pattern is required by some local codes and for enhanced wind coverage on certain products.
The warranty language is where the patterns matter. GAF ties its highest wind speed coverage to a special installation: LayerLock-labeled shingles with four nails plus starter at eaves and rakes, and all other GAF shingles with six nails plus starter at eaves and rakes. Coverage is conditioned on the shingles being installed strictly in accordance with the application instructions, so we install the pattern your coverage requires.
Ventilation: Balanced Intake and Exhaust
Ventilation is code work, not an upsell. The residential code requires a minimum net free ventilating area of 1/150 of the vented space, reduced to 1/300 only where both conditions are met: a Class I or II vapor retarder on the warm-in-winter side of the ceiling in Climate Zones 6, 7 and 8, and 40 to 50 percent of the required area in upper ventilators within 3 feet of the ridge with the balance in the bottom one-third. The vapor retarder condition does not apply here, since the IECC county table places Collin County in Climate Zone 3A and Dallas County in Zone 2A.
In practice that means a continuous ridge vent paired with adequate soffit intake, sized from the vent’s published net free area. GAF rates its Cobra Rigid Vent 3 at 18 square inches per linear foot of net free ventilating area and states that exhaust ventilation must never exceed the intake at the soffits or eaves. Adding exhaust without intake pulls conditioned air out of the house.
Shingle Classes: Wind, Impact and Insurance Credits
Two rating systems get confused constantly. Wind classification comes from ASTM D3161 and ASTM D7158, and the code classification table for asphalt shingles ties the required class to design wind speed, narrowing to D7158 Class H and D3161 Class F as speeds rise. Impact classification is a different test, UL 2218, in which steel balls of increasing diameter are dropped on the product. Our guide to choosing your shingles lays the options side by side.
| Rating | Standard | What it means |
|---|---|---|
| Wind class D, G, H | ASTM D7158 | Class H accepted at the highest design wind speeds |
| Wind class A, D, F | ASTM D3161 | Class F accepted at the highest design wind speeds |
| Impact Class 1 | UL 2218 | Withstands a 1.25-inch steel ball |
| Impact Class 2 | UL 2218 | Withstands a 1.5-inch steel ball |
| Impact Class 3 | UL 2218 | Withstands a 1.75-inch steel ball |
| Impact Class 4 | UL 2218 | Withstands a 2-inch steel ball, the highest classification |
The ball diameters above are as published by IKO; GAF describes the Class 4 test as a 2-inch steel ball dropped from 20 feet with the back surface checked for cracks. Shingles are also made to ASTM D3462, which as NRCA’s Professional Roofing explains evaluates products as manufactured rather than after installation.
On insurance credits we describe only what the Texas Department of Insurance publishes. TDI states that materials must be tested for impact resistance at a laboratory under a recognized standard, that qualifying materials are classified as Class 1, 2, 3 or 4 and that a Class 4 roof covering would receive the highest premium credit, and that the amount of discount for each class is established by the insurance company on a company-by-company basis. Ask your carrier what it offers.
TDI also advises homeowners that some companies give discounts for roofs with wind, hail, or fire resistant materials and that many policies reduce coverage based on a roof’s age and materials. We are not a public insurance adjuster and we do not negotiate claims on your behalf. For storm work we provide the construction record through our insurance restoration documentation process, alongside hail damage restoration and storm restoration.
Cleanup, Permits and Project Closeout
We protect landscaping and hard surfaces before tear-off, keep debris moving to the dumpster, and run rolling magnets over drives, walks, and turf daily and again at completion. Permit and inspection requirements vary by city, so we confirm what your jurisdiction requires for your address and handle the filing and scheduling. At closeout you get a walkthrough, the product documentation for warranty registration, and photographs of the concealed work.
Frequently Asked Questions
How long does a roof replacement take in North Texas?
Most residential replacements are completed quickly once materials are staged, though timelines vary with roof size, complexity, weather, and material availability.
What materials do you install?
We install roofing systems appropriate for North Texas weather and review impact-resistant shingle options and ventilation during your inspection. Shingles, underlayment, leak barrier, edge metal, starter, ridge cap, and vents are selected as one system.
Is my replacement storm-related?
If storm damage is suspected, we inspect and document the conditions and provide construction estimates, photographs, measurements, and code documentation related to the work. We are not a public insurance adjuster and we do not negotiate claims on your behalf.
Why do you tear off instead of installing over the old shingles?
The 2021 International Residential Code defines roof replacement as removal of existing layers of roof coverings down to the roof deck, and it prohibits a recover where the existing covering is water soaked or deteriorated below an adequate base, or where the roof already has two or more layers. Tear-off is also the only way to inspect the decking.
What is the difference between a 4-nail and a 6-nail pattern?
The code sets a floor of not less than four fasteners per strip shingle, and manufacturers publish both a standard pattern and an enhanced high-wind pattern. GAF describes a standard pattern with four nails and an enhanced pattern with six, and its limited warranty ties maximum wind speed coverage to the correct pattern plus starter strip at eaves and rakes.
Are Class 4 impact-resistant shingles worth it in Dallas and Collin County?
Class 4 is the highest impact classification under UL 2218, and this is hail country. The Texas Department of Insurance notes that a Class 4 roof covering would receive the highest premium credit and that the amount of any discount is established by each insurance company. Ask your carrier what it offers.
What voids a manufacturer system warranty?
Installation that departs from the manufacturer’s published application instructions. Coverage is specifically conditioned on the shingles being fastened and installed strictly in accordance with those instructions, and accessory coverage can depend on which components of the same system are installed.
Do you handle interior water damage or fire damage cleanup?
We do not perform water or fire mitigation, drying, or remediation. Where mitigation is needed we handle mitigation and remediation partner coordination to get properly licensed companies onsite, and we self-perform the reconstruction and build-back afterwards.
Start with a documented roof inspection, review financing options, and see our roofing services and service areas. When you are ready, contact our Richardson office.