Roof Sheathing High Wind Areas

Roof slopes greater than 4 12 require only one layer of underlayment.

Roof sheathing high wind areas.

When the wind pressures the roof it lifts the sheathing off the roofs structure and frame. Special wind regions and topographic factors identified in asce 7 engineered design is recommended. Windstorm panels are engineered to allow the use of the continuous sheathing methods allowed by building codes. Building codes regarding the type number and spacing of fasteners must be followed.

Consult with local codes and builders for the accepted practice. Oriented strand board osb or plywood can be used although plywood will provide higher nail head pull through resistance. When the sheathing is solid you can choose a proper material. Fasteners should be 3 8 inch from panel ends and 3 8 inch from panel edges see hints below.

The sheathing is the fastened to the rafters it acts like a top layer of the roofing. In high wind areas more fasteners may be required. Uplift resistance of the roof sheathing. Sheathing type typically 15 32 inch or thicker panels are required in high wind areas.

Shingle and shake roofs may also be applied to solid sheathing at exposed eaves and rakes and similar locations. At intermediate supports fasten panels 12 inches on center. In areas prone to hurricanes and high winds loss of roofing materials and sheathing is a primary concern. Sheathing type typically 15 32 inch or thicker panels are required in high wind areas.

In very windy areas solid sheathing is often used. Oriented strand board osb or plywood can be used although plywood will provide higher nail head pull through resistance. As a best practices approach an augmented underlayment can provide an effective secondary. Increase the uplift resistance of the roof sheathing.

The ability of a roof sheathing panel to resist high winds is directly related to how well it is secured to the roof framing. For pitched roofs wear skid resistant shoes. Use panels rated as exposure 1 or better. The type and number of fasteners required for a specific application is obviously an the engineered wood association apa.

The roof to wall connection under high wind loads is subject to both uplift and shear due to positive or negative wind pressure on the walls below. If the sheathing is properly installed there will be no damage made by high winds. Use panels rated as exposure 1 or better. Underlayment in high wind areas i e where wind speeds are 110 mph or greater must be secured with corrosion resistant fasteners spaced no more than 36 inches apart.