US20080060295A1

US20080060295A1 - Sill plate and method of use

Info

Publication number: US20080060295A1
Application number: US11/520,365
Authority: US
Inventors: Christopher W. Powanda
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-09-13
Filing date: 2006-09-13
Publication date: 2008-03-13

Abstract

The present invention provides a sill plate for use between a foundation and a frame of a structure for attaching the frame to the foundation. The sill plate includes an elongated sill board and a compressible seal member attached to a side of the sill board, the seal member for placement adjacent the building foundation for sealing the joint between the foundation and the sill plate. In a preferred embodiment, the sill board is formed of a composite material including wood or reclaimed wood. Additionally, the present invention provides a method of installing a sill plate on the foundation of a building.

Description

FIELD OF THE INVENTION

The present invention generally relates to a sill plate for use in the construction industry, and more particularly to a sill plate including a composite sill board and a seal member attached to the sill board for use between a building foundation and a frame of the structure and method of use of the same.

BACKGROUND OF THE INVENTION

In the construction of new structures such as single and multiple family dwellings, condominiums, and light commercial buildings, local and national building codes usually require the installation of two sill members between the concrete foundation and framing of the structure securing the framing to the foundation and for providing a seal therebetween. The first or bottom most sill member is typically a polyethylene foam membrane which is installed on the concrete foundation over anchors secured to the concrete. The second sill member is a sill plate usually formed of pressure treated lumber (e.g., 2″×6″ pressure treated boards) installed over the foam membrane and secured to the foundation using the anchors. The foam membrane acts as a sealant between the poured concrete or concrete block foundation and the pressure treated sill plate. Typically, the framing for the structure is installed on top of the sill plate and secured to the sill plate and foundation via the anchors.
The foam membrane often includes an adhesive for attaching the foam membrane to the concrete foundation. Usually the adhesive is protected with an additional cover layer designed to be removed during an installation process.
While the above-identified prior art sill members and sill plates are widely used and meet national and local codes, serious problems associated with this type of sill members still exist, some of which can lead to a failure of the sill plates. Failure of a sill plate could compromise the structural integrity of an entire building. Common causes of failure associated with the above-described prior art sill plates include termite damage, rot due to high moisture, and damage caused by boring insects including carpenter ants. Additionally, pressure treated lumber may not be properly treated thoughout the entire board which may cause the board to rot prematurely and lead to failure of the board.
The risk of sill plate failures has become even greater with the recent changes in treatment methods and the chemicals used as preservatives to treat pressure treated lumber. The Environmental Protection Agency has banned chromated copper arsenate (CCA) as a preservative for wood intended for residential use. Accordingly, in an effort to make alternative preservatives effective, the copper content in the preservatives has been increased substantially. One disadvantage of increasing the copper content in treated lumber is that the corrosiveness of the lumber is also increased. According to the American Wood Preservers Association, typical pressure treated lumber currently available in the marketplace is approximately five times more corrosive than previously used lumber treated with CCA.
The corrosive effects of the new treatment processes for pressure treated lumber present a serious problem for the construction industry with respect to sill plates and the anchor bolts used therewith. For example, anchor bolts in contact with the treated lumber are susceptible to corrosion and can fail as a result thereof. The corrosion of foundation anchor bolts will certainly compromise the structural integrity of homes in high wind areas of the country and dramatically increase devastation in areas of the country affected by hurricanes and tornados. For slab on grade construction, the problem is increased, as foundation anchor bolts are more likely to be exposed to moisture which can increase the risk and/or rate of corrosion of steel bolts.
Another disadvantage associated with the above-described prior art sill members is that the foam membrane and pressure treated lumber are separate products which require a multiple-step installation process including, removal and disposal of an adhesive covering material from the foam membrane; installing the foam membrane and adhering the same to the foundation; and installing the sill plate on top of the foam membrane. As mentioned above, the foam membrane often includes a covering material over an adhesive which must be removed prior to installing the foam membrane on the foundation. In cold weather, the adhesive may not seal properly to the foundation such that the alignment between the foam and the sill plate or the foundation could be compromised. Alternatively, if the foam membrane is installed without removing the adhesive covering material, the joint between the foundation and the foam membrane may be unsatisfactory as the foam membrane will not properly engage the concrete foundation with the adhesive covering therebetween.
Further, the two separate products (foam membrane and pressure treated sill plate) are typically handled separately from ordering the materials through the installation thereof, which adds to the cost of the structure and increases the risk of error during an installation process. For example, if the foam membrane is not present on a job-site, the sill plate may be installed without the foam membrane which could result in an unsealed joint between the sill plate and the foundation. Further, because the foam membrane and sill plate are installed separately, each piece must be separately aligned with the foundation during the installation process.
Based on the foregoing, it is the general object of the present invention to provide a sill plate and method of use that improves upon, or overcomes the problems and drawbacks associated with prior art sill plates.

SUMMARY OF THE INVENTION

The present invention provides a sill plate for use between a foundation and a frame of a structure which includes an elongated sill board, and a compressible seal member attached to a side of the sill board. The seal member is preferably a foam membrane configured for placement adjacent the foundation for sealing the joint between the foundation and the sill board.
In another aspect, the present invention provides a method of installing a sill plate on a foundation for providing a sealed joint between the sill plate and the foundation.
Preferably, the sill board of the present invention is manufactured from a composite material that is weather resistant and will not rot or splinter and is not susceptible to damage from insects. In one preferred embodiment, the sill board is an extrusion formed of a composite material including wood flour, polyethylene and other processing additives. The composite material also preferably includes antifungal and antiparasite agents and does not contain any toxic chemicals or preservatives.
In one embodiment, the sill board is approximately 5/4 inches thick and approximately six inches wide and is available in various lengths including twelve, sixteen and twenty feet long.
The seal member is attached to a side of the sill board for engagement with a foundation for sealing the joint between the sill board and the foundation. In a preferred embodiment the seal member is a compressible polyethylene foam membrane approximately ¼ inches thick and approximately six inches wide adhered to a side of the sill board. The adhesive is preferably a polyethylene adhesive such as that typically used in the construction industry.
Openings, such as holes are typically bored through the sill plate including both the sill board and the seal member for receiving a fastener for attaching the sill plate to a foundation.
One advantage of the present invention sill plate is that the composite material of the sill board is not corrosive and will not cause damage to anchor bolts or other fasteners used therewith. Accordingly, structures attached to sill plates of the present invention are less susceptible to damage caused by sill plate failures than those built on sill plates of the prior art.
Another advantage of the present invention sill plate is that the sill board and seal membrane attached thereto is a one piece assembly that installs on a foundation in one step which reduces the cost of installation when compared to prior art sill plates and the foam membranes used therewith.
Another advantage of the present invention is that the sill plate does not require any adhesives for the installation thereof, thus even in cold or wet weather, the sill plate can be installed and provide a weather-tight seal between a foundation and the sill plate.
A further advantage of the present invention is that the sill board and seal member are pre-aligned such that there is no need to separately align the seal member with the foundation during an installation process. Accordingly, there is no risk of the seal member folding or slipping during an installation process which can occur with prior art sill plates.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of embodiments of the invention and the attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a sill plate in accordance with the present invention shown mounted to a concrete foundation.

FIG. 2 is a perspective view of a sill plate in accordance with the present invention.

FIG. 3 is an end view of the sill plate of FIG. 2.

FIG. 4 is a partial top view of the sill plate of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-4, an embodiment of a sill plate in accordance with the present invention is generally referred to by the reference numeral 10. The sill plate 10 includes a generally rectangular sill board 12 having first and second opposing sides 14 and 16 respectively, opposing edges 13, and opposing ends 15 and 17. A seal member 18 is attached to the second side 16 of the sill board 12 and aligned therewith.
Preferably the sill board 12 and the seal member 18 are of substantially the same width W and aligned width-wise one with the other along a length L of the sill board 12. The sill board 12 and seal member 18 cooperate to define a plurality of holes or openings 20 which extend through both the sill board and the seal member for attaching the sill plate 10 to a foundation 22. (See FIG. 1). Typically, the openings 20 are holes bored through the attached sill board 12 and seal member 18 in the field.
Referring again to FIG. 1, a plurality of anchor bolts 24 are typically secured to the foundation 22 and extend outwardly from a top side 26 thereof. Normally, as used with concrete foundations, the anchor bolts 24 are placed in the foundation 22 prior to the concrete being fully cured and are secured thereto once the concrete cures around the anchor bolts. An end portion 28 of the anchor bolts 24 is usually threaded for receiving a nut (not shown) and securing the sill plate 10 and/or a frame member (also not shown) to the foundation 22.
Typically, the openings 20 (See FIG. 1) are circular holes bored through both of the attached sill board 12 and seal member 18 in the field. Normally, the openings 20 define a diameter larger than the diameter of the anchor bolts 24 such that the position of the sill plate 10 can be adjusted slightly relative to the foundation 22 and/or adjacent sill plates.
The sill board 12 is preferably made from an extruded wood thermoplastic composite lumber (WTCL) product which includes wood flour, high density polyethylene as well as other processing additives. The composite lumber material also preferably includes one or more antifungal and antiparasite agents. In one preferred embodiment, the sill board 12 includes a minimum of about 50 percent wood flour by weight and a maximum of about 50 percent high density polyethylene and processing additives by weight. When subjected to tests involving weathering, insect attacks, and other decaying elements, the above-described preferred WTCL composite material of the sill board 12 meets or exceeds the durability and performance of both preservative-treated or naturally durable lumber. The above-described WTCL sill board 12 has been evaluated and shown satisfactory performance for use within a temperature range of about negative 20 degrees Fahrenheit to about 125 degrees Fahrenheit. Although, the preferred embodiment of the sill board 12 is a composite material including wood flour and polyethylene, the scope of the invention is not limited in this regard as other composite materials which include wood, reclaimed wood, plastic, polymers, cement or other wood substitutes can also be utilized and are within the scope of the invention.
Referring to FIGS. 2-4, the seal member 18 is preferably a flexible foam gasket fully adhered to the side 16 of the sill board 12 via an adhesive layer 19. The adhesive layer 19 is a polyethylene construction adhesive, however other types of adhesives could be utilized without departing from the scope of the invention. Alternatively, the seal member 18 can be secured to the sill board 12 with other types of fasteners such as staples.
In a preferred embodiment, the seal member 18 is a compressible polyethylene foam strip approximately one-quarter inch thick and six inches wide for use between the sill board 12 and the foundation 22 to reduce air infiltration between the foundation and the sill board. The seal member 18 is a preferably a closed-cell polyethylene foam which provides a durable seal even when exposed to water and/or water vapor. Although the seal member 18 is foam, other compressible materials can also be utilized for the seal member without departing from the scope of the invention.
Referring to FIG. 2, the seal member 18 includes an end portion 21 which extends beyond the end 15 of the sill board 12 a distance identified by the letter X which in the illustrated embodiment is approximately equal to the width W of the sill board. At the opposing end 17, the sill board 12 extends beyond the end of the seal member 18 a distance X also equal to about the width W of the sill board. The end portion 21 provides an overlapping seal at the joints at the corners of a foundation 22 or between sill plates 10 arranged end to end along a wall of the foundation forming a ship lap type joint between the seal member 18 and and an adjacent sill board 12. The overlapping seal formed by the end portion 21 helps to ensure a proper seal at the joints between adjacent sill boards 12. If the end portion 21 of the seal member 18 is not useful in a particular application, such as at the corner of a foundation, the end portion can easily be removed by cutting the material of the seal member flush with the end 15 of the sill board 12 using an ordinary utility knife or another cutting tool.
In another embodiment of the present invention sill plate 10, the seal member 18 can be approximately the same length L as the sill board 12 wherein the end portion 21 is not provided. Alternatively, the seal member 18 can be configured to include an end portion 21 extending beyond the length one end 15 of the sill board 12 and end flush with the opposing end 17 thereof.
The sill plate 10 is preferably a pre-fabricated assembly including the sill board 12 and the seal member 18 adhered thereto. Preferably, the seal member 18 is adhered to the sill board by applying a layer of an adhesive 19, such as a settable polyethylene adhesive, to one or both of the surfaces 16 of the sill board and a surface of the seal member, joining the two surfaces together, and allowing the adhesive to set. Additionally, a roller or compression device can be used to attach the adhesive to the mating surfaces and ensure adhesion therebetween.
In use, the sill plate 10 of the present invention can be installed in one step on the top surface 26 of a foundation 22. Typically, prior to installing the sill plate 10, any dirt and loose debris is removed from the top surface 26 of the foundation 22. Next, the sill plate 10 is aligned with the foundation, the location of the anchor bolts 24 marked on the sill plate, and the openings 20 (i.e., holes) are drilled through the sill plate. One method of marking the sill plate 10 for drilling the openings 20 therethrough includes positioning the sill plate 10 on top of the anchor bots 24 with the surface 14 of the sill board resting on the anchor bolts and aligning the sill plated with the foundation. By striking the bottom of the sill plate over top of the anchor bolts with a hammer, the anchor bolts will mark the surface 14 of the sill board 12 thereby marking the location for the openings 20 to be drilled through the sill plate 10.
To install the sill plate 10 on the foundation 22, the sill plate is positioned on the top surface 26 of the foundation 22 with the seal member 18 facing the foundation and the anchors 24 extending through the openings 20 in the sill plate. If the openings 20 allow for adjustment of the position of the sill plate 10 relative to the foundation 22, the position of the sill plate can then be adjusted relative to the foundation as necessary which completes the installation process.
Typically, following the installation of a frame member on top of the sill plate 10, nuts are secured to the anchor bolts 24 which draw the frame member (not shown) and the sill plate 10 towards the foundation 22 thereby securing the same thereto. Tightening the nuts on the anchor bolts 24 causing the frame member and sill plate to be drawn towards the top surface 26 of the foundation also compresses the seal member 18 thereby forming a weather-tight seal between the foundation and the sill plate 10.
The installation of the sill plate 10 does not require aligning the sill board 12 with the seal member 18 as the sill plate is provided with the seal member attached to the sill board. Further, there is no adhesive required to install the sill plate 10 as the present invention does not require an adhesive between the foundation 22 and the seal member 18. Since installation of the sill plate 10 does not require any adhesives, the sill plate can be efficiently installed in any weather conditions including cold and wet weather and provide a sealed and weather-tight joint between a foundation and the sill plate.
The foregoing description of embodiments of the invention has been presented for the purpose of illustration and description, it is not intended to be exhaustive or to limit the invention to the form disclosed. Obvious modifications and variations are possible in light of the above disclosure. The embodiments described were chosen to best illustrate the principals of the invention and practical applications thereof to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

Claims

1. A sill plate for use between a foundation and a frame of a structure, the sill plate comprising:

an elongated sill board having two opposing sides, and

a compressible seal member attached to one of the two sides of said sill board, said seal member for placement adjacent the foundation for sealing the joint between the foundation and said sill board.

2. The sill plate according to claim 1 wherein said sill board comprises a composite material.

3. The sill plate according to claim 1 wherein said seal member is attached to said sill board with an adhesive.

4. The sill plate according to claim 1 wherein said sill board and said seal member define at least one opening through both said sill board and said seal member for receiving a fastener for attaching said sill plate to said foundation.

5. The sill plate according to claim 1 wherein said seal member extends beyond an end of said sill board.

6. The sill plate according to claim 2 wherein said composite material includes wood flour.

7. The sill plate according to claim 2 wherein said composite material includes wood or reclaimed wood.

8. The sill plate according to claim 2 wherein said composite material includes a polymer.

9. The sill plate according to claim 1 wherein said seal member includes a foam membrane.

10. A sill plate for use between a foundation and a frame of a structure, the sill plate comprising:

an elongated sill board formed of a composite material, and

a compressible seal member adhered to a side of said sill board, said seal member for placement adjacent the foundation for sealing the joint between the foundation and said sill board.

11. The sill plate according to claim 10 wherein said composite material includes a minimum of about 50% wood flour by weight.

12. The sill plate according to claim 10 wherein said composite material includes a maximum of about 50% polyethylene by weight.

13. The sill plate according to claim 10 wherein said seal member includes a foam membrane.

14. The sill plate according to claim 10 wherein the seal member extends beyond the end of the sill board at one end of the sill board and the sill board extends beyond the seal member at the other end of the sill board.

15. A method of installing a sill plate on a foundation of a building, the method comprising the steps of:

attaching a seal member to a sill board forming a sill plate, and thereafter

mounting said sill plate on a top surface of a foundation such that said seal member engages a top surface of the foundation for sealing the joint between said sill plate and the foundation.

16. The method of installing a sill plate in accordance with claim 15 wherein the step of mounting includes compressing the seal member between said sill plate and the foundation.

17. The method of installing a sill plate in accordance with claim 15 wherein the step of attaching includes adhering said seal member to said sill board.

18. The method of installing a sill plate in accordance with claim 15 further comprising a step of defining a plurality of openings in said sill plate for attaching said sill plate to said foundation.

19. The method of installing a sill plate in accordance with claim 15 wherein the step of attaching further comprises extending said seal member beyond at least one end of said sill board such that said seal member is longer than said sill board and extends beyond the length thereof.

20. The method of claim 17 wherein the step of adhering includes using a settable adhesive and allowing the adhesive to set prior to installing the sill plate.