U.S. patent application number 11/062778 was filed with the patent office on 2005-09-08 for threaded rod wind and seismic resistance system.
Invention is credited to Brackett, Charles T..
Application Number | 20050193681 11/062778 |
Document ID | / |
Family ID | 34914919 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050193681 |
Kind Code |
A1 |
Brackett, Charles T. |
September 8, 2005 |
Threaded rod wind and seismic resistance system
Abstract
Wood framed walls of buildings are strengthened against
destructive wind and seismic forces by a threaded hold-down rod
attached to the structure top plate and anchored to the building
foundation. The foundation structure may be concrete or other floor
joist or the like. The threaded rod is normally used in a system
that attaches at top and bottom of studs at approximately every
fourth or fifth stud along all load-bearing walls. The threaded rod
system comprises two sections of threaded rod connected to the
structure by way of a nut and washer at the top plate and embedded
in the foundation at the bottom. A short section of threaded rod is
embedded in the foundation and a coupling nut connects the short
section to the remaining threaded rod section near the bottom
plate. The short section may be manufactured of galvanized steel or
stainless steel to avoid corrosion where fastened to a pressure
treated bottom plate. In an alternate embodiment, an elongated wire
bolt rod can be attached to the foundation and directly to a roof
truss and ceiling plate. The described system can be installed
during initial construction of a structure or retrofit into
existing structures.
Inventors: |
Brackett, Charles T.;
(Jacksonville, FL) |
Correspondence
Address: |
Jeffrey C. Maynard
154 Barbara Road
Severna Park
MD
21146
US
|
Family ID: |
34914919 |
Appl. No.: |
11/062778 |
Filed: |
February 22, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60546633 |
Feb 21, 2004 |
|
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Current U.S.
Class: |
52/698 |
Current CPC
Class: |
E04H 9/028 20130101;
E04B 1/26 20130101; E04H 9/14 20130101; E04B 2001/2684 20130101;
E04B 2001/3583 20130101 |
Class at
Publication: |
052/698 |
International
Class: |
E02D 027/00; E04B
001/38; E04C 005/00 |
Claims
What is claimed is:
1. A system for bracing a wood frame structure, comprising: an
elongated threaded rod attached to a top plate of said wood frame
structure; a stubby threaded rod attached to a foundation of said
wood frame structure; and a coupler joining said elongated threaded
rod and said stubby threaded rod, wherein said stubby threaded rod
passes through a bottom plate of said wood frame structure and is
embedded in said foundation.
2. The system of claim 1, further comprising: a nut and washer to
attach said elongated threaded rod to said top plate.
3. The system of claim 1, wherein the system is placed within a
wall of said wood frame structure.
4. The system of claim 1, wherein said elongated threaded rod is
the same diameter as said stubby threaded rod.
5. The system of claim 2, wherein said coupler has internally
threaded female fittings on both ends and said coupling is sized
and configured to receive a threaded rod of the same size on each
end.
6. The system of claim 1, wherein said elongated threaded rod is a
smaller diameter than said stubby threaded rod.
7. The system of claim 6, wherein said coupler has internally
threaded female fittings on both ends and said coupling is sized
and configured to receive a threaded rod of one size on a first end
and a treaded rod of a second same size on a second end.
7. The system of claim 1, further comprising: a nut and washer to
attach said elongated threaded rod at said bottom plate.
8. The system of claim 1, wherein said elongated threaded rod is
replaced by a wire bolt having a threaded connection of each
end.
9. The system of claim 1, wherein said elongated threaded rod
comprises a steel rod having a diameter selected from the group
consisting of: 1/2-inch; 3/8-inch; and 1/4-inch.
10. The system of claim 1, wherein said stubby threaded rod
comprises a steel rod having a diameter selected from the group
consisting of: 5/8-inch; 1/2-inch; 3/8-inch; and 1/4-inch.
11. The system of claim 1, wherein said stubby threaded rod
comprises stainless steel.
12. The system of claim 1, wherein said stubby threaded rod
comprises galvanized steel.
13. The system of claim 1, wherein said stubby threaded rod
comprises zinc coated steel.
14. A method of strengthening a wood frame building structure to
resist high wind and seismic conditions, such method comprising the
steps of: a. forming a socket in a foundation of such structure
through a floor plate of such building frame; b. attaching a first
section of threaded rod to the foundation by inserting said first
section of threaded rod into such socket and fastening such first
section of threaded rod to the foundation; c. forming an elongated
tunnel through a ceiling plate of such building frame; d. attaching
a second section of threaded rod to the ceiling plate by inserting
said second section of threaded rod into such elongated tunnel and
fastening such second section of threaded rod to the ceiling plate;
and e. attaching said first section of threaded rod to said second
section of threaded rod by a coupler.
15. The method according to claim 14, wherein the diameter of said
first section of threaded rod is the same as the diameter of said
second section of threaded rod.
16. The method according to claim 14, wherein the diameter of said
first section of threaded rod is greater than the diameter of said
second section of threaded rod.
17. The method according to claim 16, wherein said coupler
comprises a reducing coupler.
18. The method according to claim 14, wherein said first section of
threaded rod is attached to said foundation by means of said
threaded rod being embedded in the foundation and sealed in place
by a suitable adhesive.
19. The method according to claim 14, wherein said first section of
threaded rod is attached to said foundation by means of a
compression anchor embedded in the foundation.
20. The method according to claim 14, wherein said first section of
threaded rod comprises steel selected from the group consisting of:
stainless steel; galvanized steel; and zinc coated steel.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This Application claims the benefit of U.S. Provisional
Application, Ser. No. 60/546,633 entitled Threaded Rod Wind and
Seismic Resistance System, filed with the U.S. Patent and Trademark
Office on Feb. 21, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to wood frame building
structures, and more particularly to structures exposed to extreme
wind and/or seismic conditions where building codes dictate that
these structures be protected against structural failure and/or to
save lives of occupants. In particular, the present invention
relates to a hold-down system for anchoring the structure of a wood
frame building to resist uplift forces encountered during a high
wind or seismic situation. The present invention also relates to a
system of threaded rods that provides additional reinforcements for
an existing structure.
[0004] 2. Background of the Prior Art
[0005] It is well known what high winds can do to a building,
particularly to a wood frame construction low-rise structure.
Generally, uplift forces tending to lift the roof off the structure
or the entire structure off its foundation cause much of the damage
sustained by the building.
[0006] Wood structures predominate in residential and light
commercial construction, and when wood framing is employed, the
structure must be protected from upward, shear and overturning
loads developed by either wind or seismic activity, which differs
with geographical location and is enforced by different building
codes for these areas. For example, the Bahamas and Florida
coastline, including the Florida Keys are situated in the pathway
of the yearly Caribbean hurricane travel course and as such,
encounter hurricanes and/or tornadoes from time to time.
[0007] In the case of upward loads, the building is generally tied
to the foundation using a variety of steel connectors that tie the
bottom plate to the foundation, wall studs to bottom plates, top
plate to wall studs, floors to walls, and roof to walls. Typically,
for uplift, connectors are attached to every stud (16" O.C.), or at
least every other stud (32" O.C.). Shear and overturning loads are
resisted by a combination of heavy-duty steel connectors, (either
bolted to, or embedded in, the foundation, and nailed or bolted to
the wood frame), and an approved structural sheathing material
nailed directly to the exterior of the structure is used to create
what is referred to as a "shear wall". The size and number of such
steel connectors vary depending on the severity of the wind and/or
seismic conditions expected in the locality of the building, and
the building's geometry.
[0008] In the current method used in the United States, such
connectors are installed during the foundation and framing stages
of construction. Laborers hired by the framing contractor generally
install the connectors and sheathing. Correct size, location and
number of fasteners (nails, screws, or bolts), are critical to the
required load. Commonly, these laborers are inexperienced which
frequently results in improper or inadequate installation. In all
structures, the locations of most connectors mandate their
installation during the framing stage due to related building
components being placed at the same time. This process slows the
foundation and framing stages of construction, which in turn
increases labor costs. In addition, existing structures without
having appropriate connectors in place are at risk of destruction
should a hurricane or earthquake occur.
[0009] From the foregoing, it is apparent that there is a critical
need for a structural tie-down system that provides for uplift,
shear and overturning loads that is cost effective and easy to
install and that can be installed after the foundation and framing
stages of the building are complete.
[0010] The various features of novelty that characterize the
invention will be pointed out with particularity in the claims of
this application.
SUMMARY OF THE INVENTION
[0011] The present invention provides a solution to the above
problem by reinforcing and anchoring the structure to the ground,
wherein a hold down force is applied to the wall studs to counter
the uplift and horizontal forces generated by high winds. The
present invention can be incorporated during initial construction
of the structure or retrofit into preexisting structures.
[0012] It is an object of the present invention to provide a
threaded rod anchor system for a structure of a wood frame building
that reinforces the structure against damage in a high wind
situation, such as a hurricane.
[0013] It is a further object of the present invention to enable
installation of a threaded rod anchor system after the foundation
is set, without prior embedding anchor bolts. A related object is
to enable installation of a threaded rod anchor system after the
roof, wall framing, and exterior sheathing are in place.
[0014] It is another object of the present invention to provide an
anchor system for a frame construction building that provides a
downward force around the periphery of the structure, thereby to
better resist any upward lift imparted to the walls and roof by
high winds. It is still another object of the present invention to
provide an anchor system for a low-rise, wood frame building that
can be easily installed in preexisting structures. A related object
is to enable increased uplift resistance in pre-existing structures
with minimum invasion of wall members. A further related object is
to increase value in structures existing in high wind and seismic
zones.
[0015] It is another object of the present invention to provide an
anchor system for a wood frame building that provides reinforcement
to the walls and roof structure, thereby providing greater
resistance to damage during high wind conditions. A related object
is to increase public safety in structures existing in high wind
and seismic zones.
[0016] It is a further object of the present invention to eliminate
the need for hurricane clips and straps to be installed at top and
bottom plates in the construction of a wood frame building.
[0017] It is yet another object of the present invention to enable
cost effective construction of wood frame structures while meeting
all Building Code requirements. A related object is to provide an
anchor system for a building that complies with the recommendation
of all major building codes.
[0018] This invention relates to a novel method of bracing a wood
framed building, e.g., a residential dwelling, having a structure
including a foundation upon which rests a plurality of parallel
vertical studs separating horizontal bottom plates from horizontal
ceiling plates. The structure is reinforced against the destructive
forces of the atmosphere and of seismic origin by a system of
threaded rods between vertical studs and between bottom plates and
ceiling plates, at much greater spacing than 32" O.C. In a
preferred embodiment, a vertical connection is made between such
horizontal bottom plate and horizontal ceiling plate, and the
concrete foundation. The system comprises two sections of threaded
rod connected to the structure by way of a nut and washer at the
top plate and embedded in the foundation at the bottom. A short
section of threaded rod is embedded in the foundation and a
coupling nut connects the short section to the remaining threaded
rod section near the bottom plate.
[0019] Recent changes to EPA regulations require that a more metal
corrosive treatment be used in pressure treated wood. The
treatments that are currently used have been banned. Therefore, in
frame construction where pressure treated wood comes into contact
with metal (i.e. threaded rods) it is necessary to use a corrosive
resistant material, such as galvanized or stainless steel. It is
obvious that to place full-length rods from the foundation slab to
the top plate will be extremely expensive and drive costs up.
Accordingly, the present invention is vital to reduce cost and
prevent corrosion by using a short section of galvanized or
stainless steel rod of a length that will be long enough to
establish adequate embedment depth into the concrete foundation,
typically 6 inches, and to pass through the pressure treated bottom
wall plate approximately 3 inches. After that, the short section of
rod can connect to a standard, non-coated rod with a coupling and
then on through to the top plate.
[0020] The threaded rod system disclosed herein offers more body,
more strength, and more durability to the purchasing public. Such
threaded rod system may be made from different combination of sizes
of the smaller diameter, upper longer rod and the short larger
diameter rod at the bottom to fit many framing applications and
strength requirements. Such threaded rod anchor system creates a
solid attachment between the foundation and the ceiling top plate.
This simple invention enables a threaded rod anchor system that can
be easier to install and more reasonably priced and that, in fact,
can be made or put in place by any skilled or semi-skilled
person.
[0021] The various features of novelty that characterize the
invention will be pointed out with particularity in the claims of
this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other features, aspects, and advantages of the
present invention are considered in more detail, in relation to the
following description of embodiments thereof shown in the
accompanying drawings, in which:
[0023] FIG. 1 is an elevational view of a typical load bearing wall
section employing the present invention;
[0024] FIG. 2 shows an illustration of one embodiment of the
present invention;
[0025] FIG. 3 shows an enlarged portion of FIG. 2 illustrating an
embodiment of the present invention as connected to the top
plate;
[0026] FIG. 4 shows an enlarged portion of FIG. 2 illustrating an
embodiment of the present invention as connected to the bottom
plate; and
[0027] FIG. 5 is a cross sectional view of a method of embedding a
threaded rod in a foundation according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The invention summarized above and defined by the enumerated
claims may be better understood by referring to the following
description, which should be read in conjunction with the
accompanying drawings in which like reference numbers are used for
like parts. This description of an embodiment, set out below to
enable one to build and use an implementation of the invention, is
not intended to limit the enumerated claims, but to serve as a
particular example thereof. Those skilled in the art should
appreciate that they may readily use the conception and specific
embodiments disclosed as a basis for modifying or designing other
methods and systems for carrying out the same purposes of the
present invention. Those skilled in the art should also realize
that such equivalent assemblies do not depart from the spirit and
scope of the invention in its broadest form.
[0029] FIG. 1 shows a typical load bearing wall section employing a
threaded rod system according to the present invention, indicated
generally as 10. Wall studs 13 may be single or doubled and serve
to connect ceiling plate 16 with bottom plate 19. Such bottom plate
19 may be manufactured of pressure treated lumber. In a typical
construction, the threaded rod system 10, would be used on each
side of all load bearing exterior corners, within 12-inches of each
corner and on each side of all openings 6-feet or greater. Such
system would also be used at an average of 6-feet on center
intervals in between and along bearing walls having uplift loads.
This corresponds to approximately every fourth or fifth stud along
such load-bearing wall. In an alternate embodiment, a wire bolt
system can be used in place of the full-length threaded rod.
[0030] Referring to FIG. 2, a threaded rod system 10 is
illustrated, having an elongated threaded rod 21 connected at its
top end to top plate 16 and connected at its bottom end to a
coupler 25. The threaded rod system 10 is situated between wall
studs 13 and within the inner wall 22 and outer wall 23. Threaded
rod 21 may comprise a 1/2-inch, 3/8-inch, or 1/4-inch steel rod
having threads along its entire length. In an alternate embodiment,
threaded rod 21 can be replaced by an appropriately constructed
wire bolt having a threaded portion at each end.
[0031] As further illustrated in FIG. 3, an aperture is created
through top plate 16 to enable threaded rod 21 to pass
therethrough. Top plate 16 may consist of double plates 26, 27 as
would be apparent to those skilled in the art. Threaded rod 21 is
passed through the aperture and secured by a suitable washer 28 and
nut 30 above the top plate 27. Nut 30 has internal threads to
engage threaded rod 21.
[0032] Threaded rod 21 is connected at its bottom end to a coupler
25, as shown in FIG. 4. Coupler 25 has an internally threaded
female fitting on both ends. In one embodiment, coupler 25 is sized
and configured to receive a threaded rod of the same size on each
end. In another embodiment, coupler 25 comprises a reducer coupling
wherein coupler 25 is sized and configured to receive a threaded
rod of one size on a first end and of a second size on the
remaining end. For example, coupler 25 may be sized to receive a
5/8-inch stubby rod 36 on one end and either a 1/2-inch, 3/8-inch,
or 1/4-inch threaded rod 21 on the other end. In another
application, coupler 25 may be sized to receive a 1/2-inch stubby
rod 36 on one end and either a 3/8-inch or 1/4-inch threaded rod 21
on the other end
[0033] As further illustrated in FIG. 4, threaded rod system 10
further comprises a stubby threaded rod 36 embedded in the building
foundation, as described below. An aperture 39 is created through
bottom plate 19 to enable stubby rod 36 to pass therethrough.
Stubby rod 36 may be secured by a suitable washer 41 and nut 43
above bottom plate 19. To conform to present EPA requirements for
avoiding corrosion, if bottom plate 19 comprises pressure treated
lumber such stubby rod 36 should be zinc coated or constructed of
galvanized steel or stainless steel. Stubby rod 36 is connected to
coupler 25 on such coupler's bottom end. Stubby rod 36 may comprise
a 5/8-inch, 1/2-inch, 3/8-inch, or 1/4-inch steel rod having
threads along its entire length. In a preferred embodiment, stubby
rod 36 is of a larger size than threaded rod 21.
[0034] Referring to FIG. 5, stubby rod 36 is embedded in foundation
45. Preferably, the foundation 45 is poured and bottom plate 19 and
foundation 45 are subsequently drilled to form a socket 55 to
receive stubby rod 36. Socket 55 is partially filled with a
suitable adhesive 59, for example, epoxy, polymers, expanding
cements, etc. It is understood that foundation other than slab
foundations are within the purview of this invention such as a
basement or stem wall which may have a wood floor system between
the bottom plate and the embedment into concrete. When using a
threaded rod as the stubby rod 36, such rod should be embedded at
least 6-inches into foundation 45 and should be long enough to
extend approximately 3 inches above bottom plate 19.
[0035] In an alternate embodiment, stubby rod 36 may be held in
socket 55 by a compression anchor fitting embedded in foundation
45.
[0036] The invention has been described with references to a
preferred embodiment. While specific values, relationships,
materials and steps have been set forth for purposes of describing
concepts of the invention, it will be appreciated by persons
skilled in the art that numerous variations and/or modifications
may be made to the invention as shown in the specific embodiments
without departing from the spirit or scope of the basic concepts
and operating principles of the invention as broadly described. It
should be recognized that, in the light of the above teachings,
those skilled in the art could modify those specifics without
departing from the invention taught herein. Having now fully set
forth the preferred embodiments and certain modifications of the
concept underlying the present invention, various other embodiments
as well as certain variations and modifications of the embodiments
herein shown and described will obviously occur to those skilled in
the art upon becoming familiar with said underlying concept. It is
intended to include all such modifications, alternatives and other
embodiments insofar as they come within the scope of the appended
claims or equivalents thereof. It should be understood, therefore,
that the invention may be practiced otherwise than as specifically
set forth herein. Consequently, the present embodiments are to be
considered in all respects as illustrative and not restrictive.
* * * * *