The present invention relates generally to edge boards used at the ends of board members employed in construction structures such as for example, decking, flooring and siding assemblies.
Construction structures often involve the use of long board members, which are affixed in longitudinal, parallel alignment with each other. For example, decking or other types of flooring assemblies typically include horizontal floorboards/deck boards supported on a substructure. For decking assemblies, the deck boards and usually the supporting substructure are supported above ground level, often with the assistance of structural support posts.
Decking assemblies are often formed from a substructure formed with interconnected joists and headers. Several board members of lumber or other material are then typically transversely fixed across the joists of the sub-frame, in a generally parallel relationship, by way of nails driven through the top surface of the boards.
These decking assemblies, while being adequate for most general purposes, exhibit several shortcomings. These include compromised structural integrity, difficulty in assembly, and limited aesthetic appeal. The use of nails with wooden boards in conventional decking assemblies exhibits each of these problems.
Alternative ways of constructing decking assemblies which have been proposed, include the use of a nailing anchor to fix boards to a sub-structure from their bottom surface. Examples of such decking assemblies are disclosed in U.S. Pat. No. 4,620,403 to Field; U.S. Pat. No. 5,775,048 to Orchard; U.S. Pat. No. 4,965,980 to Leavens; and in Canadian Patent number 2,015,733 to Commins. While the use of a nailing anchor may address aesthetic concerns, such assemblies are typically time-consuming to assemble. Moreover, they do not address any of the more important structural concerns arising from the use of nails in a wooden structure.
Equally as significant, the use of nails or other fasteners driven into wood boards makes disassembly and repairs of decking assemblies difficult. Moreover, disassembled boards typically include nail markings and holes from previous assembly, and are not easily re-used.
To avoid some of the shortcomings of wooden boards, the use of polymer/plastic boards has been proposed. Polymer boards do not rot or decay like wooden boards. However, unlike wood, plastic and polymer boards quite susceptible to variations in temperatures, particularly with respect to changes in physical dimensions.
More recently deck boards made from composite materials, particularly those classified as reinforced fiber plastic composites (RFP composites), and natural fiber, thermoplastic composite (NFTPC) materials have been used. The latter class can use a mix of a thermoplastic resin and one or more natural fiber materials. The natural fibers that have been employed include but are not limited to natural wood fiber, wood flour, shell fiber, flax fibers, rice hulks and other agricultural fibers. Various types of thermoplastic resins can also be employed in the composites including but not limited to polyethylene, polypropylene, polyvinyl chloride and engineering thermoplastics.
However, deck boards made from materials such as plastic or NFTPC materials, and which are usually exposed directly to changes in the outside environment, particularly changes in temperature, have shortcomings in deployment resulting from the thermal expansion and contraction of the deck board members. This is particularly the case, where deck boards of relatively large lengths are required. For example, a deck board made from a mixture of materials such as natural wood fibers and a binding thermoplastic resin such as polypropylene, has a coefficient of thermal expansion that may be in the range of about 1-5 m/m/degrees celsius×10 minus 5. Thus, a deck board that is 7 meters (700 cm) long will, during a temperature change from 30 degrees celsius in summer to minus 20 degrees celsius in winter, may experience a change in length of in the range of about 0.35 to 1.75 cm in length.
Aside from thermal expansion, some materials can significantly expand in dimensions, particularly longitudinally, when certain other conditions are changed. For example, increased moisture in the environment can lead to increased moisture content in some materials. This in turn can lead to an increase in the dimensions of the board members.
Such dimensional instability may be a particular problem at the end of the boards at the end or side of a decking area. The result on a deck may be boards which protrude beyond the desired edge plane of the deck in summer and/or boards which provide gaps either at the ends, or between consecutive boards in winter.
Other types of non-plastic, and non-plastic composite boards, are also capable of significant expansion, particularly in the longitudinal direction.
Accordingly, an improved system that addresses some of the existing shortcomings of using plastic and members in known decking assemblies and other construction applications is desirable.
According to one aspect of the invention there is provided an edge member comprising an enclosed lower channel defined by lower channel wall portions; an upstanding wall portion extending from the lower channel wall portions, the upper wall portion defining an open channel and providing an opening into the open channel.
According to another aspect of the invention there is provided an assembly comprising a supporting substructure; at least one longitudinally extending board member supported on the substructure, the board member having an end portion; an edge member mounted proximate the end portion of the board member, the edge member comprising: a lower portion configured for attachment to the substructure; an upstanding wall portion extending from the lower portion, the upper wall portion defining an open channel and providing an opening into the open channel; the edge member being attached to the substructure and the end portion of the board member being received through the opening of the edge member into the open channel, wherein the channel can accommodate longitudinal expansion and contraction of the board member such that the end portion remains substantially within the open channel of the edge member.
According to another aspect of the invention there is provided an assembly comprising: a supporting substructure; first and second longitudinally extending board members supported on the substructure, the first and second board members each having an end portion; first and second edge members mounted in back to back relation to each other, the first edge member also mounted proximate the end portion of the first board member, the second edge member also mounted proximate the end portion of the second board member, the first and second edge members each comprising: a lower portion configured for attachment to the substructure; an upstanding wall portion extending from the lower portion, the upper wall portion defining an open channel and providing an opening into the open channel; the first and second edge members being attached to the substructure, and the end portion of the first board being received through the opening of the edge member into the open channel, the end portion of the second board member being received through the opening of the second edge member into the open channel, wherein the channels can accommodate longitudinal expansion and contraction of the first and second board members such that the end portions remains substantially in the open channels of the edge members.
Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
In figures, which illustrate, by way of example only, embodiments of the present invention,
Decking assembly 10 preferably includes a substructure 11 including headers 12 placed around a plurality of joists 14 spaced evenly apart at a preferred distance of approximately 16 inches on center, and in a parallel relationship to one another. Headers 12 and joists 14 may be made of any decking supporting material, including but not limited to untreated and treated solid wood and metals including steel and aluminum.
Transversely placed upon the joists 14 are a plurality of boards 16 spaced evenly apart in parallel relationship to one another and held down on the substructure 11 by way of hold down clips 24. It will be appreciated that while deck assembly 10 is shown with only one board 16 spanning the end joists 14a, 14b, a plurality of boards could be employed in end-to-end longitudinally aligned relation to provide for a larger separation between the outermost joists 14a, 14b.
A possible shaped board that can be formed by such a process, is board 16 shown in
The dimensions of board 16 may be the same as conventional boards of lumber. Preferably, board 16 will be configured as nominal 2×3; 2×4; 2×6; 2×8; 2×10; or 2×12 boards, and have lengths which may vary depending on the size of the decking assembly or other application. Additionally, the preferable number of ribs 20 per board 16 is five. Of course, these specifications are merely examples of possible embodiments and many variations are possible.
Preferably boards 16 have coefficients of thermal expansion of greater than 1 m/m/degrees celsius×10 minus 5 and more preferably have coefficients of thermal expansion of greater than 5 m/m/degrees celsius×10 minus 5.
Also as shown in
Hold-down clip 24 optionally includes a pre-formed bore 30, extending from the center of top portion 25. Bore 30 is sufficiently large to allow a fastener, preferably such as a nail or screw to pass from the center of the top of clip 24 down through the center of the spacer tab 28. Two small solid disks 32 formed as a result of the injection molding process forming spacer tab 28, protrude from the bottom of spacer tab 28, and are located on either side of the hole on the bottom surface of the spacer tab 28.
A screwdriver bit 36 which has its operative end extending a distance preferably at least the distance from the top outer edge of the angled edge 23a of flat surface 22a of board 16 to the top inner edge of the angled edge 23b of flat surface 22b of board 16, and most preferably a distance greater than the thickness of board 16. Bit 36 has a shaft that is sufficiently thin to allow the adjustment of a screw positioned between two boards 16 while permitting a minimum separation distance between the boards 16. Thus, preferably, the diameter of screwdriver bit 36 will be less than the thickness of spacer tab 28. Screwdriver bit 36 may be a Robertson, Philips, or slotted fit, complementary to screws that may be used to fasten the boards to the substructure 11.
Other types of board attachment mechanisms could also be employed, particularly those which permit the longitudinal frictional sliding movement of the board.
The construction of a decking assembly as illustrated in
Screw 38 is positioned in the top hole 30 of hold-down clip 24 and is turned by a screw driver, preferably fitted with screwdriver bit 36 so that screw 38 is engaged by the complementary bit 36 and driven through the hold-down clip 24 into the joist 14, causing a downward force to be exerted on hold-down clip 24. The downward force on hold-down clip 24 acting upon the angled edges 23b of flat surfaces 22b causes a camming force to be exerted on each board 16 in a generally horizontal direction, orthogonal to the downward force, and towards hold-down clip 24 as illustrated by arrow P in
The combination of the cam force and the downward force causes a strong union between each board 16 and the sub-structure, as well as between each board 16 and each adjacent board 16, resulting in an improved deck function. Moreover, hold down clips 24 spaced along the length of the boards may cause adjacent boards to be equally and evenly spaced and parallel, eliminating the need measure or mark the position of boards 16, as they are being assembled. Preferably, several clips identical to hold-down clips 24 are spaced lengthwise to coincide with the joist spacing.
Advantageously, hold-down clips 24 need not be fixed from the top surface of boards 16, nor through any surface of boards 16. Each hold-down clip 24 is economical to produce, unobtrusive, and results in an aesthetically pleasing deck.
As boards 16 are symmetrical, downwardly extending lips 23a will be adjacent to each other. So arranged, these facilitate water run-off from an assembled decking assembly 10, and additionally prevent uneven board edges that may cause tripping or interfere with snow removal.
As should now be appreciated, if a decking assembly so assembled needs to be disassembled, fasteners may be removed from hold-down clips 24. Boards 16 remain undamaged by any such disassembly. Moreover, as the boards are symmetrical, any board having a damaged or discolored face may easily be reversed, by loosening the associated fasteners keeping the board in place, and turning the board upside down, and thus reversing the board. Similarly, severely damaged boards may be replaced, one by one, as required. This, in turn, may significantly extend the useful life of any such decking assembly.
The deck assembly 10 as shown in
Accordingly, with reference to
Board 40 as illustrated, is configured with longitudinally extending webs including a front, a rear, side wall portion 46 positioned opposite a front, front side wall portion 48. Interconnecting web portions 53 and 56 provide an enclosed longitudinally extending channel 42. Channel 42 does not have to be square or rectangular in cross section. Indeed, if made from lumber, a hollow channel 42 need not be present at all.
An open, longitudinally extending channel 44 is formed by an upstanding rear wall portion 55 that extends from wall portion 46 and transverse webs 56 and 50. An opening into channel 44 is provided between the ends of webs 50 and 56. The upper, outward facing surface of web portion 50 has an end portion 52 that is wedge shaped, tapering to a narrow tip. This provides a graduated threshold feature which reduces the tripping hazard when installed. Angle alpha may in some embodiments in the range of 15-20 degrees and most preferably about 17.5 degrees for a board that has an outer width of about 1.5 inches. Surface 52 could also in other embodiments be arcuate shaped with the surface being oriented concave downwards.
The use of edge board 40 is shown in
Edge board 40 is shown in
Edge board 40 has its outer rear face 48a mounted flush against the face of the joist 14b. Thus, the end 16a is positioned into channel. As shown in
As shown is
For appearance purposes, as shown in
In an example embodiment, joist 14 is a nominal 2×8 piece of regular lumber. Edge board 40 is configured with the same outer dimensions as a 2×4 inch piece of lumber, and skirting board 150 is configured with the same outer dimensions as a 1×6 piece of regular lumber.
With reference to
Boards 116a are supported by and attached to joists 114e-g including outer end joists 114e and 114g. A first edge board 140a is mounted to joist 114e. Boards 116a have first end portions received in openings 154 of the edge board 140e, as described above. Screws 138 pass through opposite end portions of boards 116a pass into joist 114g to pin these end portions to the joist 114g. In this manner, any thermal expansion or contraction will be forced to occur at the first end portions, which are covered by edge board 140e.
Boards 116b are supported by joists 114h, 114i and 114j in a similar manner. An edge board 140d is shown mounted to joist 114h. Boards 116b have first end portions received in openings 144 of the edge board 140d, also as described above. Screws 138 pass through opposite end portions of boards 116b and pass into joist 114h to pin these end portions to the joist 114h. In this manner, any thermal expansion or contraction will be forced to occur at the first end portions of boards 116b, which are covered by edge board 140d. The boards 116a, 116b are secured to the other joists 114e, 114f, and 114i, 114j, respectively using clips 124 which can be like clips 24.
Positioned between joists 114g and 114h, can be a transversely extending, additional breaker board member 141 which can be made from any suitable material such as for example regular lumber or be a NFTPC channel member similar to the board member shown in
A ledger board or rim joist 112 (which may be another piece of lumber like joists 114) is shown in shadow outline, and may be mounted to the ends of joists 114e-j in a known manner.
One way of assembling deck assembly 110 is as follows. First the substructure is formed which includes joists 114e-j are mounted in position, typically being attached to a header like board 112, and may be supported by beams and structural support posts (not shown). Thereafter, the support member 241 affixed such as by screws of nails to joists 214g and 214h. Next, breaker board member 141 can be installed between joists 114g and 114h, supported by support member 141. Next the deck boards 116a and 116b are mounted to the joists using screws like the screws 238 and clips 124. The outer ends of deck boards 116a and 116b can then be appropriately cut off to make the ends even. The cutoff position on the boards will be selected depending upon the ambient temperature. If the ambient temperature is relatively warm, an overhang of 1-2 cm can be left beyond the outer edge surface plane of outer joists 114e and 114j.
By way of example only, for boards 116a, 116b that are up to a maximum of 20 feet long, the amount of intrusion into the channel 144 that should be provided for when cutting of the ends of the boards can be extracted or extrapolated from the following chart. For given ambient installation temperatures, and for XTENDEX deck boards manufactured by Carney Timber Company, made from rice hulks, a resin of High Density Polyethylene, combined with certain functional additives such as pigments, lubricants, coupling agents, UV stabilizers, the intrusion allowed in to the channel can be extracted/extrapolated as follows:
Thereafter, edge boards 140a and 140d are mounted to the joists 114e and 114j respectively, with the ends of boards 116a and 116b being received with sliding transverse movement of the edge boards 140a into their open channels 144. Screws like screws 138 can then be used to hold the edge boards 140a, 140d in position on the joists 114e and 114j, as described above.
With reference to
Boards 216a are supported by and mounted with clips 224 to joists including end joists 214e and 214g, as shown. A first edge board 240a is shown mounted to joist 214e and a second edge board 240b is mounted to joist 214g. Boards 216a have their end portions received in channel openings of the edge boards 240a, 240b, in a manner like that described above.
Likewise, boards 216b are supported by and mounted with clips 224 on joists including end joists 214h and 214j shown. A third edge board 240c is shown mounted to joist 214h and a fourth edge board 240d is mounted to joist 214j. Boards 216b have their end portions received in channel openings of the respective edge boards, as described above.
A header board 112 (which may be another piece of lumber like joists 14e-h and not shown in this Figure), and may be mounted to the ends of joists 214e-j in a known manner.
Edge boards 240b and 240c are positioned in back to back relation as shown, and can be supported by a support member 241. The support member 241 can be a nominal 2×4 piece of lumber or other suitable member, and is affixed such as by screws of nails to joists 214g and 214h. The back to back positioning of medial edge boards 240b and 240c provides for a smooth transition zone on the deck surface between the two spans 260 and 262. Although there is a raised portion resulting from the upper web portions of edge boards 240b and 240c, the sloped surface portions reduce the potential tripping problems associated therewith. Likewise the sloped surface portions of edge boards 240a and 240b reduce the potential tripping problems at edges of the deck spans 260 and 262.
As shown in
It will be appreciated that edge boards like boards 40 can be provided around all edges of a deck.
One way of assembling deck assembly 210 is as follows. First the substructure is formed which includes joists 214e-j are mounted in position, typically being attached to a header like board 112, and may be supported by beams and structural support posts (not shown). Next, support member 241 can be installed between joists 214g and 214h. Next the deck boards 216a and 216b can be inserted into the open channels of edge boards 240b, 240c respectively and are mounted to the supporting joists using screws like the screws 238 and clips 124. Screws 238 are used to pin the deckboards medially along their length so that the boards will expand/contract substantially the same amount in each of the channels of the edge boards that cover their ends. The opposite ends of deck boards 216a and 216b can then be appropriately cut off to make the ends even. The cutoff position and the insertion position of the opposite ends of the boards into the channels of edge board members 240b, 240c, can be selected dependent upon the ambient temperature and the length of the board, in a manner similar to that described above in relation to
Thereafter, edge boards 240a and 240d are mounted to the joists 214e and 214j respectively, with the ends of boards 216a and 216b being received with sliding transverse movement of the edge boards 240a into their open channels. Screws like screws 238 can then be used to hold the edge boards 240a, 240d in position on the joists 214e and 214j, as described above.
Thereafter edge board 240e can be secured to a header board with the sides of boards 216a, 216b being received in the channels.
The positioning of where the board is fixed relative to the underlying substructure, can be adjusted depending upon the particular application or situation.
Although edge boards 40 have been depicted for use with deck boards in a decking assembly, they could also be used in other applications, where there is concern for thermal expansion of boards. For example, boards susceptible to expansion and contraction might be employed on siding, and a structure could be employed to utilize edge boards. In such a case, the siding members would typically, but not necessarily, run horizontally, and the edge board members could be employed vertically at the ends of the run on a wall.
The above described embodiments, are intended to be illustrative only and in no way limiting. The described embodiments of carrying out the invention, are susceptible to modification of form, size, arrangement of parts, and details of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.