Not Applicable
This invention relates to a rafter air infiltration block which partially blocks the openings which connect an attic space and the overhanging eaves. It prevents air infiltration except through a roof rafter vent and prevents a loss of blown-in insulation.
Originally, insulation was rarely used in housing as energy costs were low. As houses began to be more heavily insulated, building codes developed to ensure that the homeowner would have a properly insulated home. Soffit or rafter vents chutes were developed to work with blown in insulation which otherwise completely blocks air circulation from the eaves into the attic. While these worked very well, a continuing problem area is in how to properly block the area under the vent chutes that leads to the eaves. These areas are referred to as xe2x80x9ccold comersxe2x80x9d or xe2x80x9cwind washxe2x80x9d where the wind may pass up through the soffit vents and reach the uninsulated wood, causing a very cold spot that reaches into the residence area.
Standard trusses account for about 90% of all roof trusses. They may be of a single height where a gusset plate attaches a 2 by 4 to an angled truss to form the roof line. In such a case, a single height gap of about two inches is left. The other main truss type uses a wedge block that causes a double height gap to exist which needs to be sealed.
Typical solutions to this problem are shown by Eury, U.S. Pat. No. 4,581,861 which discloses a stiff sheet having multiple tabs that may be folded in place. Cantrell, U.S. Pat. No. 4,185,433 shows another baffle board construction using a sheet of stiff, scored material which may be folded in place. Finally, some constructions have attempted to combine a vent chute with a baffle board as shown by Pearson, U.S. Pat. No. 5,007,216.
Builders use anything from specially cutting exterior sheathing to fill the gap and then sealing the gaps left with a sealant or manually cut pieces to fit each gap. Batting is also sometimes folded and stuffed into the space but is prone to getting wet and rotting.
An acceptable air infiltration device needs to be easily installed and should be usable in a variety of truss arrangements and vent chute configurations.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is xe2x80x9cprior artxe2x80x9d with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. xc2xa71.56(a) exists.
The invention provides an air infiltration block that provides an air impermeable barrier that is water resistant and is installed readily with or without a wide variety of vent chutes and with most existing roof trusses. The single rafter block of the invention may be used in many different configurations due to its unique features. It is formed from a sheet of water-resistant material such as a waxed paper or cardboard and includes a plurality of fold lines, slits, perforation lines and tabs to allow it to function with the majority of factory truss and vent chute designs without cutting. A single block design may be ordered and stocked that will cover all jobs rather than multiple blocks, each of which accommodate a different truss or vent chute design and size.