US2055760A

US2055760A - Wall construction

Info

Publication number: US2055760A
Application number: US711102A
Authority: US
Inventors: Walter G Will
Original assignee: Certain Teed Products Corp
Current assignee: Certainteed LLC
Priority date: 1934-02-14
Filing date: 1934-02-14
Publication date: 1936-09-29
Anticipated expiration: 1953-09-29

Description

Sept. 29, 1936. w. G. WILL.

WALL CONSTRUCTION Filed Feb. 14, 1954 H HUVMH U H MWHHIQH M l. I@

mm -HUHH -......VwH ,.HHHHH -m -F 7/ MA www.. U .E l. U H Hummm 4 IJZ Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE WALL CONSTRUCTION Walter G. Will, Kenmortain-Teed Products Corporation,

e, N. Y., assigner to Cer- New York,

12 Claims.

This invention relates -to wall constructions, more especially to Wall constructions utilizing wall panels fastened upon a supporting structure. In particular the invention relates to wall boards supported -upon a 'structural frame.

Wall panels for providing a finished surface or a surface acting as a base for a finishing covering are frequently used in Walls and ceilings of building structures. Commonly such wall panels are fastened upon a frame work composed of studs and plates and sills between which the studs are fastened. Wall panels are usually made -of .such .dimensions as to be supported by `a plurality of studs when placed thereagainst. It is common practice to make Wall panels in widths which are two or three times a standard stud spacing so that kone or two studs become positioned adjacent the `central area 'of the panel when the edges of the studs are each lapped part way upon a stud of the frame structure.

Various means have been proposed for vfastening Wall panels -of the type described upon supporting surfaces and upon structural frames of the type above referred to` For the most part such fastening means have been vdriven-or passed through the material of the `panel itself into the supporting surface or into the stud of the frame. It -is thus common practice to fasten plaster boards and fibre wall boards to Wooden Astuds by driving nails through the face of the panel both into the vcentrally positioned studs and into the studs upon which the edges of the Wall board lap. Nails of limited `size are used in order that they may not be conspicuous in the finished Wall, it thus being possible with many types of wall boards to merely paint the surface or in some cas-es `to ,leave it without 'decorative covering, :the surface of the wall board being suitably finished during its manufacture. In other cases, especially to conceal the joint between boards where they may meet upon a common stud or other supporting member, battens or strips of wood o1 other material :are applied to cover the joint. 1n such lcase the .nails yare driven iiush or are slightly set in the material vof the wall panel in order that the batten may properly bear against the surface of the panel.

1n such constructions, because of the relatively small size of the nail or other fastening means, and also because of the usually limited distance bett-veen the edge of the panel and the point at which the nail must be driven therethrough in order to properly pass i-nto the supporting Stud, the holding power of the edges Aof the panels is limited, and strains brought upon the structure or upon the panel may rupture the panel. Many types of panels and wall boards are subject to change with `changes in atmospheric conditions. Experience has shown when expansion and contraction occur that the edges of the panel frequently tear :away from the nailor otherfastening means and the edge of the panel becomes loose from the stud, Thus any proper structural cooperation between the panel and the studs to form the wall is prevented and in many cases where the type of covering and its arrangement upon the supports is such that battens are not used, the panel, being free from the stud, may buckle and warp and become unsightly as well as obviously useless in forming a proper wall. Especially with fibre boards -of .such composition and form that they are subject to the absorption of moisture and variation of the content of moisture under different conditions of atmospheric temperature and humidity, the above mentioned difficulties have been experienced.

It is the purpose of the present invention to overcome these difficulties by providing a fasten* ing means which will `allow for changes in the relative positions of the supporting structure and the panel and for variations in the sizes of the panel itself so as to avoid tearing or other rupture of the panel when the strains due to these variations are brought thereupon. It is a f-urther object of the invention to provide for both lateral :and longitudinal expansion and contraction of wall boards or panels, especially those made of fibrous materials which are subject to such changes of dimension by the absorption of moisture in different degrees at different times. It is a feature of my invention that said fastening device holds Vthe Wall panel to the structure regardless of the dimensional changes of the panel and that full cooperation with the supporting structure is obtained without tearing or other rupture of the panel which would leave it free and out of engagement with the fastening means and with the supporting structure.

Moreover, with wall panels of such composition and of such materials as provide a surface which may be sligh-tly crushed in an area limited substantially to the yarea to which pressure is applied, I so form my device that it may be fastened into the `supporting structure or may be driven into a stud so as to produce this slight crushing of the surface :of the panel upon an area not substantially greater than the area of contact of the device with the face of the panel` The form of my device is such that this may be accomplished without any noticeable marring of the surface ofthe panel surrounding the fastening device and, moreover, while permitting the full expansion and contraction of the panel as referred to above. The form of my device also is such that it thus may be set in the surface of the panel so that it may be covered by battens applied over the joints between the panels or by suitable plastic material or by flexible fabric or other types of strips 0r joint covers.

The invention will be more fully understood from the following description taken in connection with the drawing in which Figure 1 shows an assembly of panels adjacently arranged in a wall structure.

Figure 2 shows a cross-section on line 2 2 of Figure 1.

Figure 3 shows one type of fastening device of my invention; and

Figure 4 shows a cross-section on line 4-4 of Figure 3.

Figure 5 shows another type of the fastening device of my invention applied to a joint between panels.

Figure 6 is a cross-section on line 6 6 of Figure 1.

Figure 1 is illustrative of my invention and shows an embodiment thereof in a wall structure having studs in vertical positions and set in laterally spaced arrangement to form the frame of the wall. In common practice such studs may be made of wood of cross-sectional dimensions 2" x 4 and the studs may be set on 16" centers and may extend from a sill at the floor to a plate at the ceiling in an ordinary building structure. Upon such a structural frame, which is taken merely as an example for illustration of the invention, are mounted panels 2. In Figure 1 is shown at the left of the gure a full panel 3 which may, for example, be 48 wide and 96 long. By mounting the panel with the lefthand edge thereof adjacent the center of the face of the stud 4 the righthand edge thereof will become positioned adjacent the center of the stud 5. Studs 6 and 'i positioned between studs i and 5 contact with the central portion of the panel.

At the right of the panel 3 are shown panels Il] and i l, each mounted with its lefthand edge la ping upon the stud 5 and adjacent the righthand edge of the panel 3. The joint i3 between the panels IB and Ii is offset with respect to the end edges 8 of the panel 3 as is common practice. As the panels I0 and H are of similar dimensions to panel 3, the righthand edges of the panels i [i and H fall upon the stud i4 adjacent the center of the face thereof and said panels are supported adjacent the center of their area by studs i5 and i6. As has been mentioned above, it has commonly been the practice to drive nails along the edges of the panels to hold said edges upon the studs ll, 5 and lll. It has also been the practice to drive nails along the upper and lower edges of the panels into the intermediate studs 6, l, i5 and I6 in addition to fastening to these intermediate studs the central portions of the areas of the panels.

According to my invention I provide a fastening means which instead of being driven through the material of the panel adjacent the edges thereof passes between the edges of adjacent panels which form a joint or is positioned adjacent an edge of a panel while being secured to or being driven into the surface of the supporting structure or into a supporting member such as the studs shown in the gure. As will be seen from Figures 3 and 5 and 6, the shank 25 of the fastening device may be of relatively small cross section so that it may pass between adjacent edges of two panels forming a joint without displacing the panels from their normal positions on the studs. Thus the fastening device does not occupy any substantial amount of space upon the stud and the edges of the panels may approach each other closely in expanding under changes of atmospheric conditions or for other reasons. Also the shank though large enough to properly hold in the stud and stiff enough to hold the panel against the stud need not be so large as to prevent a slight crusting of the edge surface of the panels to permit expansion until the edge surfaces of the panels meet.

The head 22 of the fastening device as shown in the particular embodiment of Figure 3 extends at right angles to the shank 25 to form an L shaped device. This form of the device may be used at the edges of panels whether these edges are to form joints with adjacent panels or whether they are at an end of the structure. By inserting or driving the shank into the stud with the head 22 lapping upon the surface of the panel this head may be brought to bear against the surface of the panel to hold the panel against the stud. Thus, for example, in Figure l devices of the type illustrated in Figure 3 are shown inserted in the stud i to hold the lefthand edge of the panel 3 thereagainst. Likewise, devices of this type are shown holding the upper and lower edges S of the panel 3 against the studs 5 and 'L'. At the right of panels iB and il is shown the edge of panel i2 upon the stud i 6. By way of illustration L shaped fasteners of the type shown in Figure 3 are set in staggered arrangement alternately lapped upon and holding panels E6, Il and i2 to the stud lli.

It will be noted from Figure 2 and from Figure 6 showing an enlarged section at line 6-6 of Figure 1 that the panels il and i2 are separated and there is space between the edges thereof and the L shaped fasteners. As wall board is manufactured variations in width occur. For example boards of nominal width of 48 inches may vary between 47% and 48 inches. Thus an initial separation of the boards may be provided by selecting boards of suitable width. For example an initial separation of l to IAL may be used. Expansion of the board thus may be allowed for; also if desired for certain constructions a fastening device of larger size shank may be used when the edges are separated.

Figure 5 shows another form of my device in which the head 24 extends at right angles to the shank 20 at both sides thereof to form the device as a T. The head 24 of the device shown in Figure 5 thus may overlap upon the surfaces of two adjacent panels forming a joint and this head may bear upon the surfaces of both panels to hold said panels against a common stud. In Figure 1 the device illustrated in Figure 5 is shown holding panels 3, il) and il against the common stud 5, the head 2li of each device overlapping upon the panel 3 and the panel i6 or El as the case may be. Similarly devices of the type illustrated in Figure 5 are shown at the joint I3 between the panels l@ and il to hold said panels to the studs l5 and i6.

While in the particular embodiments of the device illustrated in Figures 3 and 5 I have shown a shank which is pointed and of such length that it may be driven into a wooden stud for a distance suicient to fasten the device in the stud and to cause the head 22 or the head 24 to bear against the surface of the panels to hold said panels to the studs. Within the scope of my invention I may utilize other forms of the shank for fastening to studs of wood or to other types of structural members of different material. However, whatever may be the form of shank, which may be varied to suit the particular structure, I so form the head 22 or the head 213 that, when the device is fastened to the supporting structure or in the stud and the head bears against the surface of the panel, movement of accenno the panel with respect to the device and 'with respect .to the supportingmember may'take place. In the particular embodiments illustrated :in Figures 3 and 5 I have formed the device with elongated heads '22 or 24, these heads being so related to the shank 2t that, when the shank 12D 'is Ydriven into or otherwise fastened 4to the stud, 'the head 22 or the head 24 overlapping upon the :surface of the panel extends generally transversely to the edge of the panel. I thus provide for easy movement of the material of the panel adjacent its edge lengthwise of the head, that is, tran-sversely of the edge of the panel.

It is common experience that panel boards, particularly those of fibrous materials, capable f absorbing and giving up moisture, `move in a direction transversely of the `edge especially when the central portions of the panel are tfastened to studs or 'other supporting members .in the manner illustrated in Figure 1. The .form of the head of the device of my invention, therefore, is particularly advantageous to permit motion due to lateral expansion and contraction of the panel. However, the form Vof the head also permits `motion lengthwise :of the panel and transversely of the length of the head. While in many types of wall board the amount of expansion in these two different directions ,may :not be great the device of my invention permits this movement if it occurs, It will be noted that both of these movements are permitted by the device shown in Figure as well as that shown in Figure 3.

In using my device `with panels of a .composition and of such material structure as is capable of being slightly crushed, as referred 'to above, the form of the head of the device is such as will permit it to crush slightly the area of the panel immediately under 'the head without interfering with the lateral expansion and contraction of the panel and While maintaining its function as a fastening device bearing upon the surface of the panel. The

head

22 or 24 pf the *fastening device may be sunk in the face of the `panel to a sufficient distance to bring the top surface 26 of the head flush with the face of the panel, or slightly below this space if so desired, `in order that battens may be applied over the joint or that a plastic joint filler or a fabric joint cover may be applied. However, the kcross-section of the head of the device Ais such as to produce a minimum of crushing and to `avoid extending the crushing of the material kof the panel to any substantial degree beyond `the area immediately under the head of the device. .It also may be of such form as to cut the surface bers of iiber wall board and thus limit the extent of the indentation Aover the surface of the panel. The cross-section in many cases, may be such that in addition to permitting the later-al expansion and contraction ofthe panel, `that is, motion lengthwise of the head, it will permit motion of the panel transversely of the length kof the head, that is, longitudinally of the edge vof the panel.

As shown at the lefthand of panel 3 `lin Figure 2 of the drawing, the L shaped fasteners are driven into the stud so that the head 22 has its surface 26 flush with the outer surface vof the panel 3. A similar relation of the T shaped fastener to the panels which it holds upon the stud 5 is shown in Figure 5, the T head being driven iiush with the panels 3 and Il). At the stud 5 in Figure 2 the heads 24 of the T shaped fastener is shown bearing upon the `face of the panels and ll but .not driven in so that the surface 26 vof the head 24 is flush with the surface of the panels 3 and ll.

The particular arrangement of the fasteners and of the types :of .fasteners used in different positions in Figure l are merely illustrative to show variations of the features of my invention. Aselection of the different types of the fastening device and their arrangement in connection with particular panels and joints may be made to suit particular conditions -or as convenience requires.

In Figure 4 I have shown one form of crosssec-tion fof .the head of the device of my invention by which I may produce these results. This cross-'section being that of an inverted triangle brings a .relatively sharp edge and therefore a relatively small surface of contact to bear upon the .face :of the panel. The invention is not limited to the particular triangular cross-section illustrated, vas I may secure this small surface contact by other cross-sectio-ns. This feature, however, makes possible the limitation of the crushing 'of the panel to the area substantially beneath the head .and permits the expansion and contraction movements which have been described.

As 4an example of the dimensions of the device which I have found practical with wall boards Aat present in commercial use., the shank of the device may -be made similar to the shank of a wire nail, for example, :of No. 16 Birmingham wire gauge, which corresponds to 'a diameter `of about le. The length rof this shank may be, for example, 354i to l1/4" for wall boards which are 1/4 to in thickness. For thicker boards or for studs requiring longer length to provide the proper grip, the shank may be made longer.. It also may be made Asomewhat thicker or in some cases of less diameter. The

head

22 or 26 vof the device may be 4formed with a cross-section as a triangle having., .for example, a base M3 to tl in length and aheight of le to 1/8'. When formed as an L shaped faste-ning device as illustrated in Figure 3 the length -of the head may be to 5/8, or when formed as a T shaped device illustrated in Figure 5 the head may he 3/4 to 11/4 in length extending preferably yequal y,distances on either side of the shank 20. It will be understood that the lengthoff the head may be made suliicient to take care of the 'expansion and contraction which, for example, in some cases may amount to 1/4 to at each edge of the board. This invention -is not limited to `devices having the dimensions `here given nor to devices having the particularldimensio-nal relations shown and described. Also the triangular form of head may be modified, for example, to a half elliptical section. Variations may be made from these dimensions and relations while maintaining the feature above described permitting fexpansion and contraction.

In erecting ythe `panels to *which my invention is applied I may place the panel with respect to the supporting .structure or to the studs in the position which it is intendedlto be upon the structure and may then fasten it -to the ycentral studs Voi' the struct-ure or centrally of the area of the panel with the ordinary fastening means such as ordinary nails. However, I may use in place of ordinary nails if so desired, either of the above described forms of the fastening device of my invention. When the panel .has been secured at its central area, for example, to the studs rand 'l as vshown in Figures l and 2 of the drawing, I may 'then `secure the edges of the panel to the surfaces upon which the edges of the panel overlap case, however, the head of the fastener by the fastening means of my invention. For example, I may drive along the lefthand edge of the panel 3 in Figures l and 2, devices of L shape as shown in Figure 3 of the drawing. When the lefthand edge of the panel 3 thus has been secured to the stud 4 of the structure I may then proceed in a similar manner with the panels l and ll, securing these panels to the centrally positioned studs l5 and l5, for example, by means of ordinary nails. I may then fasten to the stud 5 the righthand edge hand edges of panels of the panel 3 and the leftl@ and il by means of my fastening device. In the drawing, as has been referred to above, at the joint upon the stud 5 I have shown the T head fastener illustrated in Figure 5. These fasteners may be driven into the space between edges of the panels 3 and Eil and into the space between the panels 3 an il, the elongated heads Zd of the fasteners being placed crosswise of the joint. These fasteners may be driven so that the surface 26 of the head is flush with the face of the panel, as shown in Figure 5 representing the arrangement of the fasteners positioned in the joint between the panel 3 and the panel lil, or they may be brought merely into holding contact with the faces of the panels as shown at the stud 5 in Figure 2 representing the arrangement of the fastener in relation to the panels 3 and il.

Instead of fastening the panels lil and I l to the studs l5 and i6 in the same manner as the panel 3 was fastened to the studs 6 and l, prior to driving the T headed fasteners along the joint upon the stud 5 I may first drive these fasteners along the edge of the panel 3 to hold said edge of the panel to the stud 5. Particularly when the head 213 of the T headed fastener is brought into contact with the face of the panel, as shown in Figure 2, I may slip the edge of the panel il, for example, under the head 26 of the T shaped device and then may fasten the panel l i to the studs l5 and i6 and thereafter fasten the righthand edge of the panel il to the stud lll. However, with wall panels of certain materials I may drive the T headed device flush with the panel 3 prior to erecting, for example, the righthand panel lil. If the panel le is composed of such material that the edge portion thereof may slightly crush or indent when the edge of the panel is pressed against and inserted under the free leg of the T shaped device, I may thus erect the panel l0 after having driven the fasteners ush with the panel 3. Preferably, however, as stated above, I erect the panel and fasten it to the centrally positioned supports and thereafter drive the device at the edge of the pane When two panels are erected in adjacent positions with their edges substantially meeting and are of such material that the shank 29 of the device may be passed therethrough, I may drive the fastening device of my invention at the meeting line of said panels, the material of each panel thereby being pressed aside but leaving the panel free of the shank of the device so that contraction thereof in a direction away from the meeting line of the joint may take place. This feature of my invention may be va-luable when panels are to be erected which are of such materials as over a period o-f time will shrink, thus causing the edges of adjacent panels to separate. In each overlaps upon the edge of the panel to such a degree as to permit this motion to take place while maintaining the panels secured in position to the stud or other supporting structure.

The invention includes any form of the device which provides for fastening in or to the structural supporting member and bearing against the face of the panel in limited area and in such a way as to permit the expansion and contraction as described above. The formation of the device as an integral or unitary member permits it to be handled in the same manner as a nail and when a pointed shank is used for insertion in penetrable material such as wood the device may be driven as a nail by means of a hammer by blows upon the head 22 or the head Modifications of the device and of the particular relation thereof to the panels as shown in Figure l may be made within the scope of my invention to permit the expansion and contraction of the panel and to permit these movements when the device is set into the face of the panel by the crushing thereof under the head of the device.

I claim:

1. In a wall construction, a supporting member, a wall panel having the edge thereof overlapping upon a part of the surface of said supporting member, and a fastening device having a portion fastened to said supporting member and positioned adjacent said edge of the wall panel but substantially free of force transmitting contact with the material of said panel, said fastening device having a rigid portion unitary with said first portion and overlapping and bearing upon the face of said wall panel with an extent suicient to hold the panel against the supporting member, the dimension of said portion transverse to said extent thereof beingsubstantially restricted to provide an area of bearing so limited as to permit movement of the panel relative to said supporting member and said fastening.

2. In a wall construction, a supporting member, a Wall panel having the edge thereof overlapping upon a part of a surface of said supporting member, and a fastening device having a shank fastened to said supporting member and extending adjacent said edge of the wall panel in a direction transverse to said surface of the supporting member but substantially free of force transmitting contact with the material of said panel, said fastening device having a leg transverse to said shank and bearing upon the face of said wall panel when said device is fastened to said supporting member to hold the panel against the supporting member, said panel being of a material capable of being indented by pressure upon the face thereof over a given area substantially without marring the adjacent areas of the face, said leg having a cross-sectional form capable of indenting the face of said panel when said device is fastened in said position to hold the panel against the supporting means but permitting movement of the panel relative to said leg and to the supporting member in a direction generally lengthwise of said leg.

3. In a wall construction, a supporting member, two wall paneis adjacently arranged to form a joint upon said supporting member, said panels being of a material capable of being indented by pressure upon the face thereof over a given area substantially without marring the adjacent areas of the face, and a fastening device having a shank passing between the adjacent edges of said wall panels toward said supporting member but free of substantial force transmitting 'contact with the material of said panel and arranged for fastening to said supporting member, said device having at least one leg transverse to said shank and bearing upon the face of one of said wall panels, said leg having a cross-sectional form capable of indenting the face of said panel when said device is fastened to said supporting member to cause said leg to hold the panel against said supporting member but permitting movement of the panel relative to said supporting member in a direction generally lengthwise of said leg.

4. In a wall construction, a stud of penetrable material, a wall panel of a composition subject to expansion and contractio-n under atmospheric changes and capable of being indented by pressure applied upon an area of the face thereof, said panel being mounted with an edge thereof lapped upon a part of said stud, and a fastening device having a shank of a form capable f being driven into said stud and having a leg transverse to said shank, said shank being driven into said stud in a position transverse to the face of the panel and adjacent said edge thereof but substantially free of force transmitting contact with the material of said panel and with said leg bearing upon the face of the panel and extending tranversely of said edge of the panel, the form of the cross-sectional thickness of said leg being such that with said shank driven into said stud to a point where the outer surface of said leg is substantially flush with the face of the panel the area of the face beneath said leg is indented but the adjacent areas of the face are not substantially marred, said leg also being of such form and cross-section along its length as to permit expansion and contraction of the panel in a direction generally lengthwise of said leg.

5. A fastening device for a wall panel mounted with an edge thereof overlapping upon a part of the surface of a supporting member of the wall structure, said device having a shank of a form to be fastened to said supporting member and having a leg transversely of said shank for bearing upon the face of the wall panel when said device is fastened to the supporting member, said leg having a cross-sectional form capable of indenting a relatively narrow area of the wall panel thereunder but avoiding substantial marring of adjacent areas of the panel, the form of said leg permitting movement of the panel relative thereto lengthwise of said leg.

6. A fastening device for a joint between adjacently arranged wall panels mounted with an edge of each thereof overlapping upon a part of the surface of a supporting structure, saiddevice having a part thereof of relatively limited thickness to extend between the edges of the panels and transversely of the face of the panels, said device having a part rigidly connected to said i'lrst mentioned part and extending transversely of said first mentioned part for bearing upon the face. of both of said panels, the length of said rst mentioned part in a direction transversely of the face of the panels being such as to cause said part for bearing upon the face of the panels to hold the panels firmly upon said structure when said rst part is fastened to said structure, the form of said part fo-r bearing upon the faces of the panels being so restricted in a direction transverse to its said extent transversely of the first part as to provide alimited surface in contact with said panels when said device is fastened in position to hold the panels upon the structure, said form being such as to permit movement of said panels transversely of said edges.

7. A device for fastening to a wall structure a wall panel of material capable of being indented by pressure upon a relatively small area thereof without substantially marring the adjacent areas thereof and mounted with an edge of the panel lapped upon a part of the surface of a supporting member of the type into which a fastening means may be driven, said device having a shank of a form to be driven into said supporting member transversely of the face thereof and having a leg transversely of said shank for bearing upon the surface of the wall panel when said shank is driven into said supporting member, said leg having a cross-section providing a V edge to bear against said face of said panel to cause indentation of said face of the panel upon a limited area when the device is driven into position to hold the panel in place.

8. A device for fastening to a wall structure a wall panel of material capable 0f being indented by pressure upon a relatively small area thereof without substantially marring the adjacent area thereof and mounted with an edge of the panel lapped upon a part of the surface of a supporting member of the type into which a fastening means may be driven, said device having a shank of a form to be driven into said supporting member transversely of the face thereof and having a leg transversely of said shank for bearing upon the surface of the wall panel when said shank is driven into said supporting member, said leg having a cross-section providing a V edge to bear against said face of said panel to cause indentation of said face of the panel upon a limited area when the device is driven into position to hold the panel in place, said V edge extending lengthwise of said leg to permit movement of the panel relative to said leg lengthwise thereof.

9. A device for fastening to a wall structure a wall panel mounted with an edge thereof overlapping upon a part of the surface of a penetrable supporting structure, said device having a nail like shank and an elongated head rigidly connected to said shank and extending at a right angle to said shank, the length of said shank being such as to bring said elongated head into contact with the face of the panel when said shank is driven into holding position in said penetrable surface of the structure, said elongated head having a cross-section of a form reducing in width in the direction lengthwise of the shank to limit any crushing of the face of the panel to an area substantially under the extent of said elongated head.

l0. A fastening device asin claim 9 in which the cross-section of the head is substantially a triangle.

l1. A fastening device according to claim 9 in which the elongated head extends across the shank to form a T therewith.

12. In a wall construction, a supporting member, a wall panel having an edge thereof overlapping upon a part of the surface of said supporting member, and a fastening device having a portion fastened to said supporting member and positioned adjacent said edge of the wall panel but substantially free of force transmitting contact with the material of the panel, said fastening device having a leg unitary with said shank extending generally parallel to the plane of and bearing upon the face of said wall panel when said device is fastened to said supporting member to hold said panel against the supporting member, said leg having the bearing surface thereof so formed as to permit movement of the panel relative to said leg and to the supporting member.

WALTER G. WILL.