Roof installation & repair: What to check in the plan
Use the roof plan to check covering, flashing, ventilation and repairs before approving a roofing order or quote.
Get dimensions from plans or a professional roof measurement. This is a homeowner’s scope checklist, not instructions to climb onto a roof or design its structure.
Describe the roof before pricing it
Record each measured plane and pitch, then eaves, rakes, hips, ridges and valleys. Name the existing covering and the proposed replacement. Keep additions and low-slope sections separate so the supplier can confirm which products and application instructions apply to each part.
Agree on tear-off and deck inspection
Ask who removes existing layers, protects the home and disposes of debris. Write down how damaged decking is documented and priced when uncovered. A shingle bundle total cannot predict hidden damage; use a written change process instead of quietly adding a guessed decking percentage.
Specify the water-shedding details
List underlayment, leak barriers, drip edges, wall and chimney flashings and penetration treatment. GAF’s Steep-Slope Pro Field Guide treats these as distinct roof-system details. Require the roofer to identify the detail for each junction rather than describing the job simply as “new shingles.”
Match the valley to the shingle
GAF Technical Advisory Bulletin R-136 says laminated Timberline shingles use open or closed-cut valleys, not woven valleys. That is a system-specific distinction, not a rule for every roof product. Ask which valley detail is included and have its measured length on the material schedule.
Keep ventilation and fastening explicit
The GAF field guide covers intake/exhaust planning and product-specific fastening. Ask for the ventilation layout, product names and the applicable fastening instructions. Do not infer vent quantity from roof area alone or treat an editable calculator example as a wind-zone or building-code determination.
Close out with a repair record
Request the agreed inspection documents, product identification, workmanship terms and pictures of work that is now covered. For a later leak, record where and when water appears and arrange assessment; do not assume the interior stain sits directly below the entry point. Keep maintenance access and fall protection with the roofing professional.
See the measurement become an order
Example only: a 30 × 20 ft footprint at 6:12 pitch, a chosen 10% allowance and editable shingle bundle coverage.
This example gives 23 shingle bundles.
- Section 1: 600 sq ft × 1.118 = 670.82 sq ft
- 670.82 × (1 + 10/100) ÷ 33.3333 = 22.14 bundles before rounding.