U.S. patent application number 12/148807 was filed with the patent office on 2008-10-23 for corrosion protection inserts for metallic construction supports.
Invention is credited to Albert J. Clarizia, Willaim F. Galloway.
Application Number | 20080256884 12/148807 |
Document ID | / |
Family ID | 39870815 |
Filed Date | 2008-10-23 |
United States Patent
Application |
20080256884 |
Kind Code |
A1 |
Clarizia; Albert J. ; et
al. |
October 23, 2008 |
Corrosion protection inserts for metallic construction supports
Abstract
An insert for construction supports such as joist hangars and
hurricane straps provides corrosion protection from chemicals and
moisture in exterior construction lumber. The insert is a
semi-rigid body having a shape that fits the construction support
so that surfaces of the insert are disposed between the support and
the construction lumber at joints in the construction. In the
preferred embodiments, the inserts are made of a plastic material
and provide a chemical, moisture and electrical barrier between the
support and exterior lumber elements of a structure.
Inventors: |
Clarizia; Albert J.;
(Hyannis, MA) ; Galloway; Willaim F.; (Lunenburg,
MA) |
Correspondence
Address: |
KENNETH S WATKINS JR
372 RIVER DR
DAHLONEGA
GA
30533
US
|
Family ID: |
39870815 |
Appl. No.: |
12/148807 |
Filed: |
April 23, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60925740 |
Apr 23, 2007 |
|
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|
Current U.S.
Class: |
52/309.3 ;
52/702; 52/741.3 |
Current CPC
Class: |
E04B 1/2612 20130101;
E04B 5/12 20130101 |
Class at
Publication: |
52/309.3 ;
52/702; 52/741.3 |
International
Class: |
E04B 1/64 20060101
E04B001/64; E04B 5/00 20060101 E04B005/00; E04C 5/18 20060101
E04C005/18 |
Claims
1. A corrosion protection insert for metallic construction supports
used in attaching a treated lumber, said insert comprising: a
semi-rigid body of a polymeric material, said body comprising a
predefined shape wherein at least two orthogonal insert attachment
surfaces of said insert fit between corresponding support
attachment surfaces of said construction support and corresponding
treated lumber attachment surfaces.
2. The corrosion protection insert of claim 1 wherein said insert
comprises an attachment means for attaching said insert to said
construction support.
3. The corrosion protection insert of claim 2 wherein said
attachment means is a tab on said insert that engages said
construction support.
4. The corrosion protection insert of claim 3 wherein said tab
comprises a J-shaped cross section to engage an edge of said
construction support.
5. The corrosion protection insert of claim 3 wherein said tab
comprises a L-shaped cross section to frictionally engage an edge
of said construction support.
6. The corrosion protection insert of claim 2 wherein said
attachment means is a male fastener element engageable with a
complementary element on said construction support.
7. The corrosion protection insert of claim 7 wherein said male
fastener element is a button tab and said complementary element is
a nail hole on said construction support.
8. The corrosion protection insert of claim 2 wherein said
attachment means comprises a pressure-sensitive adhesive disposed
on said body of said insert.
9. The corrosion protection insert of claim 2 wherein said
attachment means is an interference fit with said construction
support.
10. The corrosion protection insert of claim 2 wherein said insert
is a cured resin and said attachment means is a resin bond to said
construction support.
11. The corrosion protection insert of claim 9 wherein said insert
is a joist hangar insert comprising a generally U-shaped body
having an interference fit with inside U-shaped surfaces of a joist
hangar.
12. The corrosion protection insert of claim 1 wherein said
construction support is a joist hangar wherein said at least two
surfaces of said insert comprise a generally U-shaped portion and a
perpendicular back plate surface.
13. The corrosion protection insert of claim 12 wherein said back
plate surface comprises a slot between two legs of said generally
U-shaped portion.
14. The corrosion protection insert of claim 1 wherein said
construction support is a hurricane strap wherein said at least two
surfaces of said insert define an elongated body comprising a first
surface at a first end of said body and a second surface,
perpendicular to said first surface and disposed at a second end of
said body.
15. A corrosion protection construction support for use with
treated lumber, said support comprising: a metallic body comprising
at least two orthogonal attachment surfaces for attaching said
treated lumber; and a polymeric film attached to said metallic body
whereby said film separates said metallic body and said treated
lumber thereby preventing corrosion of said metallic body.
16. The corrosion protection construction support of claim 15
wherein said polymeric film is a cured resin bonded to said at
least two attachment surfaces.
17. The corrosion protection construction support of claim 16
wherein said polymeric film is a semi-rigid polymeric insert
attached to said metallic body.
18. The corrosion protection construction support of claim 15
wherein said metallic body is a joist hangar.
19. The corrosion protection construction support of claim 15
wherein said metallic body is a hurricane strap.
20. The corrosion protection construction support of claim 15
wherein said metallic body is a post support.
21. A method of reducing corrosion of metallic construction
supports used with treated lumber, the method comprising the step
of placing a semi-rigid, preformed polymeric insert having at least
two orthogonal surfaces between joining surfaces of said treated
lumber and said metallic construction support.
22. Said method of claim 21 wherein said insert is placed in said
construction support before assembly of said treated lumber and
said construction support.
23. Said method of claim 21 wherein said insert is engaged to said
construction support after assembly of said construction support
and a first joining surface of a first treated lumber.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/925,740 filed Apr. 23, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to corrosion protection for
metallic supports used in exterior treated wood construction, and
more particularity, for protective inserts used with galvanized
steel hangars, straps, brackets and supports.
BACKGROUND OF THE INVENTION
[0003] Steel hangars, straps, brackets and other reinforcing
supports are often used in exterior and interior construction
because of the increased strength, rigidity and safety these
supports add to the structure. Supports used with lumber,
especially exterior treated lumber are susceptible to corrosion due
to moisture and corrosive chemicals often used to prevent rot and
deterioration of the lumber.
[0004] Lumber treatment often utilizes metallic compounds, as well
as acidic or caustic compounds, which can react chemically or
electrically through galvanic corrosion to attack and degrade the
steel supports. Moisture causes chemical compounds in the lumber to
leach, further compounding the problem.
[0005] Corrosion-inhibiting methods have been used in the past to
address the problem of accelerated corrosion of steel supports.
These methods include use of highly corrosion resistant materials
in the supports such as stainless steel. Although stainless steel
reduces the corrosion due to chemical and galvanic attack, it is
expensive and requires use of stainless steel fasteners such as
screws and nails in order to be effective. Applying a layer of a
highly anodic metal such as zinc is commonly used to protect the
steel structure. Such galvanic corrosion-protection measures have
been effective in the past, but are insufficient for new lumber
treatments that include use of high metallic compound formulation,
as well as corrosive biocides and fungicides.
[0006] U.S. Patent Application Publication No. 2005/0126109
discloses an anticorrosion separator for use with galvanized joist
hangars. The separator is a membrane which separates the metal from
wood to provide corrosion protection. The membrane must be applied
to all wood surfaces in contact with the galvanized supports,
requiring considerable time for fitting the membrane.
[0007] There exists a need for a method for protecting metallic
supports from corrosion due to exterior lumber chemical and
moisture attack which is simple, quick to use, and low in cost.
OBJECTS AND SUMMARY OF THE INVENTION
[0008] Therefore, an object of the present invention is to provide
an insert for use with metallic construction supports such as joist
hangars, hurricane straps and post supports which provide a barrier
preventing the leeching of chemicals and moisture from treated wood
to the supports.
[0009] Another object of the present invention is to provide an
insert for use with metallic construction supports that provides
electrical insulation between treated lumber and the support to
reduce galvanic corrosion.
[0010] Another object of the present invention is to provide an
insert for use with metallic construction supports that can be
installed quickly and at low cost.
[0011] Still another object of the present invention is to provide
method for protecting metallic construction supports from corrosion
by providing a barrier between the support, treated lumber and
fasteners used to attach the support to the lumber.
[0012] The method of the present invention is an insert disposed
between a construction support, such as a joist hangar, hurricane
strap or post supports and construction members such as treated
wood joists and ledger boards, which prevents contact with, and
provides a barrier to reduce corrosion of the support. The barrier
may include a moisture, chemical and/or electrical barrier between
the metallic support and the lumber. In still other embodiments,
the barrier may insulate support fasteners from the support.
[0013] In the preferred embodiments, the insert is a semi-rigid
polymeric structure, shaped to fit or otherwise engage the
construction support so that when installed, the insert provides
the barrier between the support and the treated lumber. The insert
comprises at least two orthogonal faces or surfaces which are
shaped to conform to corresponding surfaces on the construction
support that attach to treated lumber surfaces attached by the
support.
[0014] The insert may be mechanically attached to the support, or
it may be installed between the support and the lumber during
construction. In the preferred embodiments, the inserts are
injection molded from high density polyethylene to provide good
corrosion resistance and sufficient rigidity for ease of
installation. The inserts may be shaped to "snap" into the supports
so that the insert is between the support and lumber, providing an
installation that is simple and fast.
[0015] Another embodiment of the invention attaches the "insert" by
applying a resin to the support and then curing the resin to
permanently bond the insert to the support. The cured resin
provides the mechanical, moisture, chemical and electrical barrier
properties to protect the support from corrosion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features, aspects and advantages of the
present invention will become better understood with regard to the
following description, appended claims and accompanying drawings
where:
[0017] FIG. 1 is a plan view of an insert for use with a joist
hangar;
[0018] FIG. 2 is a front elevation view of the insert of FIG.
1;
[0019] FIG. 3 is a side elevation drawing of the insert of FIG.
1;
[0020] FIG. 4 is a plan view of the insert of FIG. 1 showing
installation in a joist hangar, shown in dotted lines, and the
joist hanger insert of FIG. 1 between the joist hangar and a joist
and ledger board joint shown in phantom lines;
[0021] FIG. 5 is a front elevation drawing of the insert of FIG. 4
showing installation between a joist hangar and a joist-ledger
board joint;
[0022] FIG. 6 is a side elevation drawing of the insert of FIG. 4
showing installation between a joist hangar and a joist-ledger
board joint;
[0023] FIG. 7 is a plan view of an alternative embodiment of the
joist hangar insert of FIG. 1 having a slotted back plate to allow
fitting with differing widths of joists and joist hangars;
[0024] FIG. 8 is a front elevation drawing of the insert of FIG. 7,
and dotted lines of FIGS. 7 and 8 showing an alternative embodiment
having sections of the joist hangar insert attached and spaced by
joining strips;
[0025] FIG. 9 is a side elevation drawing of the insert of FIG.
7.
[0026] FIG. 10 is perspective drawing of an insert similar to the
split joist hangar insert of FIGS. 7-9 fitting into a joist hangar
and a joist fitting into the assembly;
[0027] FIG. 11 is a plan view of a post support insert;
[0028] FIG. 12 is a front elevation drawing of the post support
insert of FIG. 1 with a post support shown in dotted lines and a
post shown in phantom lines;
[0029] FIG. 13 is a side elevation drawing of the post support
insert of FIG. 11;
[0030] FIG. 14 is a plan view of a construction strap insert
attached to a construction strap by tabs or by aperture snap
elements that engage the nail holes of the strap;
[0031] FIG. 15 is a front elevation drawing of the insert of FIG.
14;
[0032] FIG. 16 is a side elevation drawing of the insert of FIG. 14
showing an alternate pressure-sensitive adhesive strip for
attachment to the construction strap;
[0033] FIG. 17 is a cross section of an alternative embodiment of
the invention showing a construction strap with integral insert
consisting of a coating of the strap formed by a cured resin;
and
[0034] FIG. 18 is a cross section of the construction strap of FIG.
17 having an insert coating on the lumber contact sides of the
strap.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The following is a description of the preferred embodiments
of corrosion protector inserts for exterior construction hangars
and brackets.
[0036] FIGS. 1-3 are plan and front and side elevation drawings,
respectively of a joist hangar insert 101 for corrosion protection
of a joist hangar used in exterior construction, such for use on
decks, porches and other exterior floor systems. FIGS. 4-6 are plan
and front and side elevation drawings, respectively of joist hangar
insert 101 installed in a typical exterior deck application and
providing corrosion protection to joist hangar 401 attaching joist
403 to ledger plate 405.
[0037] Joist hangar insert 101 comprises a back plate 103, two side
plates 105 and bottom plate 107. Insert 101 may be formed as a
single piece such as by casting, injection molding or vacuum
forming from a plastic film such as high density polyethylene, or
it may be fabricated from individual pieces and bonded or welded by
means known in the art.
[0038] Interior side plate spacing 109 is chosen to provide a fit
with standard joist width or thickness measurements. For example,
width 109 may be chosen to be approximately 1.5 inches to provide a
fit with standard 2'' dimensional exterior treated lumber such as
that used for porch or deck joists. In the preferred embodiments,
the selected width 109 will provide a loose fit with a joist, even
allowing for individual differences in lumber due to manufacturing
tolerances, moisture levels and temperature. In the preferred
embodiments, width 111 is chosen to provide a fit with the inside
of standard joist hangars, such as joist hangar 401 of FIGS. 4-6.
For example, width 111 may be chosen to provide a tight or
interference fit with the inside joist width of a standard hangar,
allowing retention of insert 101 in the hangar during joist
installation and fastening operations.
[0039] In the preferred embodiments, insert width 112, insert depth
113, insert bottom depth 115, and insert height 117 are chosen to
be at least equal to corresponding joist hangar dimensions so that
full corrosion protection exists between joist the joist hangar and
the corresponding deck members. In the more preferred embodiments,
insert dimensions 112, 113, 115 and 117 are greater than the
corresponding joist hangar dimensions in order to provide
additional corrosion protection. For example, insert width 112 is
chosen to be greater than joist hanger 401 width to provide insert
width overlap 501 of FIG. 5. Similarly, insert depths 113, 115, and
insert height 117 are chosen to provide respective width overlap
601 and height overlap 603 of FIG. 6. Inserts 101 may be made of
several heights 117 to allow use with standard joist dimensions
used in construction.
[0040] Insert 101 provides a physical barrier between the joint
surfaces of joist hangar 101 and joist 403 and ledger plate 405. In
the preferred embodiments, insert 101 is made of a material which
provides both mechanical separation, a moisture and chemical
barrier, and electrical insulation between joist hangar 401 and the
treated lumber members (joist 403 and ledger board 405). In the
preferred embodiments, insert 101 material provides good mechanical
tensile, puncture and abrasion resistance.
[0041] FIGS. 7-9 are plan view and front and side elevation
drawings, respectively of alternative embodiment 701 of joist
hangar insert 101 for accommodating varying joist and joist hangar
widths. Joint hangar insert 701 utilizes a slot 703 for providing
additional adjustment of width 109 or 111 depending on the width of
a joist such as joist 403 of FIG. 4. Slot 703 also allows an
interference fit for inserting and retaining insert 701 in a joist
hangar. Slot 703 may be a vertical through slot as shown in the
figure, or it may extend only part way of the longitudinal height
117 of the insert. Slot 703 also provides a means to accommodate
varying widths of the joist without utilizing different inserts.
Slot 703 may also extend partially through bottom portion 107 to
add additional flexibility to width adjustments.
[0042] In other embodiments, insert side portion joining strips
706, shown in dotted lines in the FIGS. 7-8, attach respective side
portions 701A, 701B at a distance represented by slot 703 and 704
width. Strips 706, disposed on back portion 103 and bottom portion
107, allow sizing insert widths 109 and 111 for the maximum joist
and hangar widths, respectively, and provide a means to adjust
widths 109 and 111 for smaller width applications by "crushing"
joining strips 706. Strips 706 also allow slight over sizing of
width 111 so that insert 701 is retained in joist hangar 401 of
FIGS. 4-6 by slight compression of sides 105 and bottom 107, before
insertion in hangar 401 of FIGS. 4-6.
[0043] The springing effect of strips 706 retains insert 701 in the
hangar, adding flexibility in component assembly. Joining strips
706 may be of various widths or thickness to allow the desired
crushing effect. Joining strips 706 may be other forms, such as
serrated or corrugated strips, or simply thinner sections of back
portion 103 and bottom portion 107, allowing compression of the
insert. Slot 708, between bottom portion 107 and back portion 103
provides a means for moisture drainage. Other apertures in bottom
portion 107 may be added.
[0044] FIG. 10 is a perspective drawing of assembly of a joist
hanger insert 1001 similar to the slotted insert of FIGS. 7-9. In
one preferred method of use, insert 1001 is inserted inside of
joist hangar 1003 before attaching joist hangar 1003 to ledger
plate 1007 by fasteners (not shown). End 1002 of joist 1005 is then
placed in insert 1001 and fasteners (not shown) used to fasten
joist 1005 to hangar 1003. Alternatively, joist 1005 with insert
1003 installed may be fastened to hangar 1003 before fastened to
ledger plate 1007.
[0045] FIGS. 11-13 are plan view and front and side elevation
drawings, respectively of alternative embodiment of insert 1101 for
use with post base supports such as post support 1111. Insert 1101
comprises a base portion 1103 and side portions 1105. Base and side
dimensions of post support 1101 are selected to fit inside post
support 1111 as shown in FIG. 12. Construction and use of post
insert 1101 is similar to joist insert embodiments described
earlier. Optional aperture 1107 may be used drainage of accumulated
moisture.
[0046] FIGS. 14-16 are plan view and front and side elevation
drawings, respectively of alternative embodiment of insert 1401 for
use with strap supports such as "hurricane straps". Elongated
insert 1401 comprises a top portion 1403 connected to a bottom
portion 1405 by connector portion 1407. Tabs 1409A, 1409B provide a
means to attach or snap insert 1401 into the interior portion of
hurricane strap 1402 as shown in FIG. 14. Tabs 1409A, 1409B may be
"U" or J-shaped shaped cross section as shown in the figures, or
they may be friction-type tabs such as L-shaped cross section tabs
which utilize friction in of leg portion 1411 against the edge of
the hangar.
[0047] In still other embodiments, button tabs such as button tabs
1413, shown on bottom portion 1405, provide engagement elements
that engage apertures such as nail holes 1415 of hangar 1402. Other
male/female or complementary engagement elements such as snap
fittings may be used. Adhesives 1603, distributed on insert 1401
such as pressure sensitive coatings or tapes may be used to attach
insert 1401 to the protected surfaces of hangar 1402. In still
other embodiments, discrete clips such as "U" clips may be used to
clamp insert 1401 to hangar 1402. These and other mechanical
attachment methods may be used with any of the embodiments of the
invention described herein.
[0048] The inserts of the embodiments described herein provide
separation and a physical moisture, chemical and electrical barrier
between treated lumber and contact surfaces of metallic structural
hangars, straps and supports. They reduce corrosion of the hangars,
straps and supports by preventing contact of the metallic elements
of the supports to the corrosive compounds in the treated lumber.
They reduce leeching of corrosive chemicals in the treated lumber
to the metallic components. They also provide electrical insulation
to reduce electrical currents, necessary for galvanic corrosion
from flowing between the metallic structural components and
fasteners and metallic compounds in the treated lumber.
[0049] The inserts of the present invention may be made from any
polymeric material that provides the desired physical separation,
moisture barrier, and electrical insulation properties desired in
the inserts. High density polyethylene (HDPE) is a preferred
material for making the inserts due to its good mechanical strength
properties, electrical insulation properties, formability and low
cost. In the preferred embodiments, the material properties and
thickness provides sufficient rigidity so that interference or
tight fits are possible with construction supports such as joist
hangars. Other polyolefins such ultra-high density or linear
density polyethylene, polypropylenes, polyvinyl chloride (PVC),
fluoropolymers such as PTFE, and other commodity and engineered
plastics. Structural fillers such as reinforcement fibers may be
added to the resins used to provide additional strength and
rigidity.
[0050] In the preferred embodiments, the inserts of the present
invention are formed by casting or molding in forms, or fabricating
from sheet material. A more preferred method of forming is
injection molding, allowing accurate, low-cost manufacturing. In
other embodiments, the inserts are vacuum formed or welded or
bonded from sheet material. The inserts may also be formed as
separate pieces, for example by separate halves 701A, 701B of FIG.
8. Or cuts can be made in the inserts after forming to provide
overlapping of slit portions such as back portion 103 of FIGS. 1-9.
Such slits provide the width adjustment features of slot 703 of
FIGS. 7-9.
[0051] In the preferred embodiments, the thickness of the inserts
is sufficient to provide adequate rigidity to allow insertion and
retention in the structural hangar components, yet thin enough to
prevent excessive separation from the lumber structural components
and to reduce cost and weight of the inserts. In the preferred
embodiments, the insert thickness is less than 0.125''. In the more
preferred embodiments, the thickness of the inserts is less than
0.100''. In the still more preferred embodiments, the thickness of
the inserts is less than 0.075''. In the most preferred
embodiments, the thickness of the inserts is less than 0.050''. In
some applications, the inset thickness may be 0.020''-0.040'' to
minimize cost and clearance issues. Structural shape sections, such
as integrally-cast ribs in the structures may also be used to
increase rigidity of the insert structures.
[0052] Still another embodiment of the present invention utilizes
application of the "insert" by dipping, spraying or brushing a
polymeric resin on the structural component and curing the resin to
form a bonded insert or coating on the structural component. FIG.
17 is a cross section of a coated structural strap 1701. The coated
strap may utilize a conventional base portion 1703 such as the
hurricane strap of FIGS. 14-16. The section is taken through a top
portion showing nail holes 1705. In the preferred embodiments,
coating 1707 is a cured polymeric resin coating all surfaces of
base potion 1703 including the interior surfaces of hail holes
1705. Coating of nail holes 1705 reduces galvanic corrosion of
fasteners such as nails or screws which would otherwise contact
interior surfaces of the nail holes. Coating of the interior
(non-lumber contacting) surfaces of strap 1703 also prevents direct
contact of the nail or screw heads with metallic surfaces of strap
1703.
[0053] In the preferred embodiments, coating 1707 is a cured
polymeric resin having good mechanical properties, good bond
strength with the base portion material, good moisture barrier
properties, and is electrically insulative. In the preferred
embodiments, coating 1707 is applied in the uncured state by
dipping, spraying or brushing, and cured after application. In the
preferred embodiments, coating 1707 is an epoxy material. In other
embodiments, coating 1707 is a polyester or other thermoset
polymer. In still other embodiments, coating 1707 is a
thermoplastic polymer.
[0054] FIG. 18 is an alternative embodiment 1801 of the coated
strap 1703 of FIG. 16 having a coating 1807 covering only a portion
of strap 1703. In the preferred embodiments, coating 1807 covers
only the portions of the strap which contact treated lumber, and
optionally, the interior portions of nail holes 1705. Partial
coating of strap 1703 reduces cost and weight of the strap. Partial
coating also allows spray and brushing application techniques for
manufacture. Although a hurricane strap is shown in FIGS. 17 and
18, the methods and structure of this invention may be applied to
any metallic structural component such as joist hangars, post
supports, and other metallic straps, supports and hangars used in
the art.
[0055] Still other embodiments of the invention utilize addition of
structural, corrosion inhibitor or biological inhibitor fillers to
the resins used in the coatings of FIGS. 17 and 18. For example,
conductive fillers having high anodic potential may be added to the
resins before curing to provide anodic protection of the structural
component itself. Or, reinforcing fillers and fibers such as
graphite or glass fibers may be added for increased structural
strength of the coating. Or, in still other embodiments, biocides
or fungicides may be added to the resin to reduce biological or
fungicidal degradation at the joints utilizing the components of
this invention. The use of these and other fillers may also be
applied to the resins used in manufacture of the inserts described
in FIGS. 1-16.
[0056] Although the description above contains many specifications,
these should not be construed as limiting the scope of the
invention but merely providing illustrations of some of the
presently preferred embodiments of this invention. Thus the scope
of the invention should be determined by the appended claims and
their legal equivalents, rather than by the examples given.
* * * * *