Method for increasing wind uplift resistance of wood-framed roofs using closed-cell spray polyurethane foam

Abstract

The invention provides a method and structural member for securing a roof or an outer wall of a building against wind forces tending to lift the roof or outer wall off the building. A structural member has a panel, said panel comprising a plurality of spaced apart beam members, and a sheathing having an inner side and an outer side, the sheathing spanning a space between adjacent beam members and being attached to the beam members such that the inner side of the sheathing is in juxtaposition with the beam members. A layer of a rigid, closed cell foam comprising a polymer adhesive composition is on substantially the entirety of said beam members and substantially the entirety of the inner side of the sheathing such that the layer on the sheathing and the beam members is substantially continuous, and adheres the sheathing to the beam members.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. provisional patent applications 60 / 945,974 filed Jun. 25, 2007; and 60 / 948,269 filed on Jul. 6, 2007; and 61 / 036,579 filed Mar. 14, 2008, which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a method and structural member for securing a roof or an outer wall of a building against wind forces tending to lift the roof or outer side wall off the building.[0004]2. Description of the Related Art[0005]It is well known that high wind forces from storms and hurricanes exert significant uplift forces and tend to lift roofs and remove side walls from a building structure. Wood, wood composite, or equivalent structures predominate in residential construction, and when wood framing is employed the structure must be protected from forces developed by high winds. Houses in the Caribbean or southeast coastal regions of the U...

AI Technical Summary

Benefits of technology

[0008]This has been accomplished according to this invention by providing a roof panel or outer wall panel, comprising spaced apart beam members, and a sheathing attached to and spanning a space between adjacent beam members; and spraying and adhering a layer of a foamable polymer adhesive composition such as a polyurethane or polyisocyanurate adhesive composition, which foamable polymer adhesive composition is preferably present in the form of foamable liquid, onto substantially the entirety of the beam members and substantially the entirety of the inner side of the sheathing such that the layer on the sheathing and the beam members is preferably substantially continuous. By substantially continuous it is meant that there are substantially no breaks or spaces in the layer, across the area on which it is deposited. A closed cell spray polyurethane or polyisocyanurate foam is applied at a uniform depth under a roof deck or side wall sheathing between the structural beams to provide additional bonding strength. This is different from filleted adhesive caulks in that it provides additional bonding strength and also significant insulation under the roof deck or side walls. This creates a conditioned attic or side wall space and seals soffit areas to deter the intrusion of wind driven rain. This also provides a significant energy savings.

Problems solved by technology

It is well known that high wind forces from storms and hurricanes exert significant uplift forces and tend to lift roofs and remove side walls from a building structure.

The installation of such ties slows the foundation and framing stages of construction, which in turn increases labor costs.

Decks of sloped roofs in residential buildings are particularly vulnerable to damage caused by wind uplift.

When a roof is removed in a storm, rain enters the building, often resulting in a total loss of the building and its contents.

The causes of wind uplift damage to roof decks can be from improper nailing techniques, wrong nails, wrong nail spacing, or poor workmanship when nails miss the structural members below or by use of an overdriven fastener.

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