Quick Notes

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Use these Quick Notes to help you study the fundamentals of inspecting a roof. These are highlights of information but your inspection education on the topic is not limited to just these points.


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Roofing Configuration Types:

  • Full Hip Roof
  • Butterfly Roof
  • Combination Roof
  • Gabel Roof
  • Mansard Roof
  • Flat Roof
  • Gambrel Roof
  • More than one layer of moisture retardant covering under roofing is a defect.
  • Edge flashings on the roof should extend at least 1⁄4 inch below the roof sheathing and backward onto the roof deck at least 2 inches. It should also be fastened down every 12 inches.

Roof Covering Materials:

  • Asphalt Fiberglass Composite Shingles
  • Concrete and Clay Tiles
  • Fiber Cement Roofing
  • Metal Shingles and Panels
  • Slate Shingles
  • Synthetic Component (Polymer)
  • Grass
  • Thatched
  • Plastic
  • Wood Shingles and Shakes
  • Masonite Woodruff
  • Asbestos Cement Shingles
  • T Lock Shingles
  • Built-Up Roof Membranes (BURs)
  • Mineral-Surfaced Roll Roofing
  • Modified Bitumen Roofing
  • Polyurethane Foam Roofing
  • Single-ply Membrane Roofing (PVC, TPO, EDPM, Rubber)

Asphalt shingle caps should extend 4 inches down on both sides.

Architectural shingles can use cut down 3 tab or special designed ridge shingles.

Siding should have 1-2 inches of clearance.

Sidewall flashing should be 4” x 4”.

Roll Roofing – two layers, first layer 18 inches wide face down, second layer 36 inches wide face up. Shingles cut back 3 inches from center line.

Metal Flashing – 24 inches wide, center ridge 1-inch-high, nailed 18 in off-center, ideally ice and water shield 18 in each side of valley.

Closed interwoven – extend 12 inches onto adjacent plane.
Closed Cut – one roof plane crosses to the next and other plane is cut back 2 inches.

Both cases one layer of 36-inch roofing felt paper, roll roofing, ice & water shield.
Should not be nailed within 6 inches of valley centerline. The roofs plumbing vent stack should extend at least 6 inches above the roof deck.

Flue pipe should extend no more than 5 feet above the roof deck without being secured.

Skylights on a roof with less than 3/12 slope must have a 4-inch curb. Skylights should always have their own

flashing. A minimum of 3 feet high, as well as 2 feet higher than any roof within 10 feet horizontally.

Install crickets on chimneys 30 inches wide to divert drainage water. NRCA recommends 24 inches wide.

Types of Chimney Flashings:

  • Step flashing
  • Counter flashing
  • Apron flashing
  • Cricket flashing
  • Backer flashing

Types of Roof Ventilation:

  • Gable Vents
  • Turbine Vents
  • Passive Vents
  • Soffit and Ridge Vents
  • Powered Vents


Roof Drainage System Specs:

Gutters should slope 1/16-inch per foot towards downspout. Every square inch of downspout is capable of discharging drainage for 100 sq. ft. of roof surface

1 sq. ft. of venting per 150 sq. ft. of attic area
1 sq. ft. of vent per 300 sq. ft. of attic area with low and high vents, or when vapor barrier installed.

Downspouts should direct water with proper extension 5 feet from the foundation of the home
5 inch gutters drain 5,500 sq. ft., and 6-inch drain 8,000 sq. ft. Gutters should slope 1/16th inch/foot.



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