Static structures (e.g. – buildings) – Cover with exterior holddown
Reexamination Certificate
1998-01-26
2001-08-07
Kent, Christopher T. (Department: 3635)
Static structures (e.g., buildings)
Cover with exterior holddown
C052S004000, C052S698000, C052S701000, C052SDIG001, C403S157000, C403S158000, C403S079000
Reexamination Certificate
active
06269593
ABSTRACT:
BACKGROUND—FIELD OF INVENTION
This invention relates to an innovative tie down that connects both pitches of a roof on a home to the foundation, especially where windows or other obstructions prevent running permanent hurricane straps to ground anchors.
BACKGROUND—DESCRIPTION OF PRIOR ART
BACKGROUND
Recent studies of hurricane damage on wood-frame buildings indicate that extensive damage was generated to a house by strong winds, when the roof rafters, roof trusses, and roof purlins twisted or were torn from the outside wall.
Roof sheathing ties all the rafters or purlins together on a wood frame house, and the roof sheathing ties all the roof a trusses together when a masonry or wood-frame house is constructed with trusses. If the rafters or trusses rack or twist from the wind forces, the roof sheathing can detach from the roof allowing rain to enter the house.
Sheathing that is tightly secured to the rafters or trusses and subsequently fastened to the walls, helps transfer uplifting forces to the walls and henceforth to the foundation. If the roof sheathing fails, the trusses collapse, and the walls usually fall down as they can not stand by themselves against strong winds.
HURRICANES
Studies of damage after Hurricane Andrew show several problems with the attachment of roof rafters and roof trusses that this invention solves.
Roof overhangs act like wings, creating huge uplifting forces during strong winds. This uplift tears apart the rafters that are toe-nailed to the header or top plate. The uplift can also twist rafters and roof trusses causing detachment.
One problem with home construction is on mis-installation of prior art hurricane clips that are made for new construction and covered by wall sheathing. After Hurricane Andrew, there were many examples of careless and inferior attachment of hurricane clips or they were entirely missing. One company has visited new construction sites and documented many examples of shoddy and incorrect application of their products.
Any uplifting wind force on the roof must be transferred to the foundation. My invention effectively ties together the roofing material, roof sheathing, and roof rafter or roof truss to the foundation, to form the most practical and economical continuous load path from the roof to the foundation.
PRIOR ART
A number of connectors have been developed to tie together the structural members of a house under construction. Up until this invention, nobody had seen how to make a connector that can be used for various-pitched roofs and be one-piece or segmented.
My co-pending application, Ser. No. 08/191,852, now abandoned, includes a retrofit hurricane clip and roof tie down. That roof tie down includes connectors that tie the roof to the rafter, and the rafter to the walls.
The leading manufacturer of wood construction connectors, the Simpson Strong-tie Company, shows no retrofit hurricane connectors in their catalog for tieing down an existing roof.
There are several retrofit apparatus for securing roofs using cables. Adams U.S. Pat. No. 5,570,545 and Winger U.S. Pat. No. 5,319,896 are both temporary, meaning a homeowner must be home to deploy and anchor the ephemeral cables. They don't protect the weak gable-end roof of a house from lifting or blowing out.
Objects and Advantages
Accordingly, several objects and advantages of my invention are that it helps secure the roof and foundation of a building to make the building a solid unit and preventing it from being destroyed by hurricanes and earthquakes.
This invention helps prevent the roof from being blown off the walls of an existing building. It keeps the roof rafters and roof trusses tightly secured to the outside sheathing and underlying top plate of the wall.
This invention helps prevent the roof rafters and roof trusses from twisting during strong winds, thereby preventing detaching of the roof material and underlying roof sheathing. It stiffens the edge of the roof and the top of the wall, helping to transfer up-lifting loads to the whole roof and walls.
Many older homes were constructed with the best materials and competent carpenters, but used the time-honored method of connecting the rafter to the top plate with nails driven into the edge of the rafter. This weak connection, called toe-nailing, is still in use today. Even if prior art hurricane clips were used in construction, the homeowner can't tell, and those clips don't hold the roof sheathing to the roof.
Mounted on the roof rafter or roof truss, my invention resists uplift, the most destructive force during a hurricane.
Still another advantage is that with the roof rafters and roof trusses better able to resist twisting, roof sheathing will stay firmly attached and roofing material will now have a better chance of staying on during strong winds and earth movements. In addition, with the sheathing now firmly connected, new materials may be attached to the roof, such as solar electric panels, without fear of them being blown off.
In areas with brush or forest fire danger, fire-proof material or heavy material, such as tile, stone or metal, can now be applied to the roof with less danger of being blown or shaken off during earth tremors or high winds.
Earth tremors and hurricanes always destroy the weakest parts of a house. By making each envelope of a house, the foundation and roof envelope into a strong unit, there will be less damage.
It is a further object of this invention that it easily, quickly, and economically protects houses from the destructive forces of hurricanes. It is a still further object that the connectors and fasteners are strong, attractive, permanent, functional, uncomplicated, simple to manufacture, easy to install, and economical. All of the embodiments can be made from a single sheet metal blank, without any welding.
A further object is that this invention can be used on various size sheathing, rafters, roof trusses, studs, wood or metal I-beams, TJI, and glue-lams, all made from wood or metal. There may be insurance discounts for homeowners who have this invention installed on their houses.
As a retrofit, a handy homeowner can install this invention, or have it installed. The homeowner can easily see that the home is protected instead of wondering if hurricane clips were installed correctly during construction, or installed at all.
Traditional toe-nailing of the rafter is at the bird's-mouth, a notch cut into the rafter where it rests on the top plate. By cutting out material from the rafter, a bird's-mouth weakens the rafter. Toe-nailing only two nails from either side grasps only a small edge of the rafter, and the nail only extends into the top 2×of the top plate.
Tests were done by the Colorado School of Mines on my co-pending retrofit hurricane clip, application Ser. No. 08/191,852. The tests showed that the rafter split lengthwise, due to uplifting force, before my 852' clip failed.
This new retrofit invention strengthens the roof to foundation connection by vastly increasing the down force on the roof.
As a retrofit, an insurance agent can observe that the home is protected and give appropriate discounts. Perspective home buyers can perceive that the building is protected, so the seller has a good selling point and can ask for a better price.
Since the roof tie down is a retrofit, and is not covered by sheathing or gypsum board, the invention is much thicker than prior hurricane clips and tensile values are dramatically increased.
Another advantage is that the roof tie down connects both slopes of a roof tied together, tremendously increasing resistance to outward thrusts. This makes the roof much stronger and able to resist more weight such as thick snow, ice, or volcanic ash, and heavy roofing material such as tile, insulated roofing, solar collectors, and satellite dishes.
This invention takes the place of a left and right prior art hurricane clip, thus cost and installation time is substantially reduced. Installation can be accomplished with a power nailer or powered screw gun.
REFERENCES:
patent: 777441 (1904-12-01), Small
pate
Horton-Richardson Yvonne
Kent Christopher T.
LandOfFree
Roof tie down connecting fork and yoke does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Roof tie down connecting fork and yoke, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Roof tie down connecting fork and yoke will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2475174