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Roof Specifications

Town of Bow Mar 2015 Code Requirements for Residential Roofs

A separate permit is required for roofing projects. The permit is obtained by completing and submitting the Roofing Permit Application Form(opens in new window).

MID – ROOF INSPECTION - Required at 25% of Installation.

Pay attention to the following sections of the Code Requirements:

SECTION R904 - MATERIALS :R904.1 Scope Roof assemblies shall be applied in accordance with this chapter and the Manufacturer’s Installation Instructions R904.2 / .3 / .4 Specs.

SECTION R905 - ROOF COVERINGS : R905.1 - R905.15.3


SECTION R907 - REROOFING : R907.1 - R907.6. Shake re-roofs allowed. Minimum # 1 grade required, 2 layers of flat roof material permitted.

Maximum # of Layers : 1 LAYER SHINGLE. 2 FLAT

Minimum wind speed – 6 nail all, 90 MPH ASTM UL D3161

R905.2.7.1 – Ice Dam Protection : Ice Barrier shall extend from the Eave’s Edge to a Point at least 24” (610mm) inside the Exterior (heated) Wall Line of the Building, for all new roof tear offs.

Tile, low slope & stone coated steel-underlayment, batts & flashing commercial flat at 50 percent complete required on Residential (not req. on COMM shingles).

Class A not required on residential / Commercial depends on specs for roof.

High wind nail required. Wind speed withstand = “ 90 mph. Sustained “.

Severe climate required.

Underlayment Required - #15 up to 6/12 and # 30 – 7/12 and above. 2 layers of underlayment required with slopes between 2/12 and 4/12.

Valley size – 18 in. minimum, 90 lb. or metal permitted.

Solid sheeting (plywood / OSB) required over plank decking at spec(i.e. 3/8”) of planks, must have a nailable surface. ( meet Mfg. Specs. To maintain warranty of materials installed ie: 1/8 th. Inch gap min. on sheeting ).

R806.2 Roof Ventilation –The Total net free area shall not be less than 1 square foot of roof vents per 150 square feet of roof area. Soffit vents are allowed.

Roof jacks / vents/ flashing / must be raised to the level of the new roof & replaced if they are in poor condition, badly rusted or otherwise deteriorated, due to deformities caused by exposure to the elements.

Subsection R903.2 is hereby amended by the addition of a new Paragraph R905.2.2, which shall read: DripEdge. Provide drip edge at eaves and gables of shingle roofs. Overlap to be a minimum of 2 inches. Eave drip edges shall extend 1 ½” inch below sheathing and extend back on the roof a minimum of 2 inches. Drip edge shall be mechanically fastened a maximum of 12 inches on center. Remove Gutters to install Metal. A Cricket or Saddle shall be installed on the ridge side of any chimney greater than 30 inches wide. Cricket or Saddle coverings shall be metal or of the same material as the roof covering.

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