US 2194086 A
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Description (OCR text may contain errors)
March 19, 1940. A HORN 2,194,086
' Q 4 PANEL JOINT CONSTRUCTION I v Filed Nov 16, 1933 Patented Mar. 19, 1940 UNITED, STATES PANEL JOINT CONSTRUCTION Erwin A. Horn, Seattle, Wash, assignor to The Speedwall 00., Seattle, Wash, a corporation of -Washington Application November 16, 1938, Serial No. 240,834
1 Claim. (Cl. 108-12) The present invention relates to a new panel joint construction for plywood surfaced roofs and similar structures subject to weather. By similar structures I intend to include the exterior siding of buildings, etc.
The principal object of the invention is to render the use of plywood as a roofing material more economical and practical. Another important objective is to provide a method adapted for quickly roofing temporary buildings at minimum expense and in such a manner that the plywood roofing material can be reclaimed and used again at another location. Another object is to insure weather tight lateral joints between abutted or loosely abutted surfacing panels by providing each such joint with a tightly sealed individual gutter. Other objects will be apparent from the subsequent description.
Since a great proportion of large sizes of plywood panels as manufactured today are securely glued bythe use'of a highly water-resistant adhesive between the plies, and, since protective coatings for wood surfaces have been developed capable of imparting excellent weather resistance, such plywood is particularly well adapted for roofing certain classes of buildings, especially temporary buildings, and has the advantage that it can be applied with a minimum of labor, since a large roof area can be covered with a few panels. Hitherto, however, such use has been unsatisfactory, especially because of the difficulty of making tight lateral joints. I
If rectangular plywood panels are laid on a opportunity for water entering through the joint to spread sideways until it is able to reach the edge of the lower course and thence leak through into the building. Also, the overlapping system requires roofing boards or very numerous rafters for support, adding still more to the expense. The need is for a system which will eliminate both lateral overlaps and board supports and at the same time reduce vertical overlaps toa minimum.
To the accomplishment of the foregoingand Also, overlapping the related ends, the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claim, the following description setting forth in detail certain illustrative k embodiments of the invention, these being indicaii tive however of but a few of the various ways in which the principle of the invention may be em- 'ployed.
The presentinvention eliminates any necessity for overlapping the lateral edges of plywood panels when such panels are used as roof covering According to the present method, suitable rectangular panels are abutted laterally on rafter supports which run up and down the slope of the v The rafters are ac- '15 roof in the usual manner. cordingly spaced to fit the panel width and allow for a looseabutment of the panels and intermediate rafters may be supplied where wide panels are used, but no roofing boards are provided as in the case of shingle roofs and the plywood panels may serve both as the weather and" theinner surfaces of the roof. Instead, however, of abutting the lateral edges directly on the bearing surface of the rafters, a channel member,
usually of metal, having short upward extending jacent to the lateral edges of the inner surface of the panels. r
In the accompanying drawing:
Figure 1 is a partial section of a roof taken 1ongitudinally of a rafter, substantially on line i--l of Figure 4.
Figure 2 shows a portion of a panel in perv spective.
Figure 3 shows a portion of a channel member in perspective.
Figure 4 is a section, enlarged substantially to,
full scale, online 4-4 of Figure 1.
Figure 5 is a partialreproduction of the showing of Figure 4, enlarged about three times.
Figure 6 is a partial section of a roof taken longitudinally of a rafter substantially on line 6-6 of Figure '7 and illustrating the lapped panel arrangement; and
Figure 7 is a section substantially on line 'l-l of Figure 6. v I
Referring first to Figures 1 to 5, reference numerals. It and II designate adjacent portions of plywood panels, such panels being usually of three (3) ply construction, as shown, and ordinarily about seVen-sixteenths (3 g) of an inch thick.
. Reference numerals l2 and I3 indicate kerfs or.
grooves extending in parallel relation to the panel edges. These kerfs are preferably at least one thirty-second of an inch wide, and are usually about one-sixteenth of an inch wide and extend about one-half A way through the panels, for example to a depth of five-thirty-seconds (a s) of an inch. Each of these grooves is spaced with its center line about three-fourths A) of an inch away from the panel edge and can be readily cut with a saw. The panels are preferably made with a highly water resistant glue, and the surfaces may be weather-proofed with a good varnish before use. It is desirable also to apply varnish or other suitable protective coating both to the panel edges and the walls of the kerfs or saw cuts.
Reference numeral l4 designates a channel which comprises the web portion l5 and legs or flanges l6 and H perpendicular to the web. The channel may be formed from about number twenty-four (24) gauge galvanized iron, or copper, or other suitable weather-resistant material. The length of the channel is preferably the same as that of the panels. As particularly shown in Figures 1, 4 and 5, the channel it extends along the top of a rafter l8. Since the standard two (2) inch dimension stock rafters are actually about one and five-eighths (1%) inches wide, I prefer that the width of the channel be about one and one-half (1 inches and the flanges three-sixteenths of an inch high when designed for use with seven-sixteenths (-56) inch plywood kerfed five-thirty-seconds 5) of an inch deep. The width of the channel is always such as to permit both adjacent margins of a pair of panels to rest in the channel with the lrerfs receiving the channel flanges, in the manner particularly shown in Figures 4 and 5. As a rule, I prefer either to dip the metal channel in roofing asphalt or other plastic weather resistant compound, or else run about one-sixteenth of an inch of such plastic material into the bottom of the channel, as indicated at IS in Figure 3.
In assembly, the channel, preferably containing suitable plastic material, is laid along the top of the rafter, and at this time it is not necessarily secured to the rafter. The panels H1 and H are now laid on the channel with the flanges l6 and I! engaged in the kerfs l2 and I3. Nails or other suitable fasteners, as at 20 and 2|, are now driven through the panel margins, and the channel web l5 into the rafter l8. As a result of this operation, by which considerable tension is exerted on the panel margins, the upper edges of the channel flanges are caused to cut into the wood which forms the inner walls of the kerfs and the plastic material is caused to flow into the kerfs and into any space which may exist between the adjacent panel edges in somewhat the manner most clearly shown in Figure 5.
Even where a sealing compound is not used, the nails driven through the plywood and channel web and thence into the rafter, although they perforate the channel, do not cause any leak, since the channel web will be tightly clamped between the wood of the lower side of the panel and that of the upper surface of the rafter, so that the holes in the web are effectively sealed. Of course, this sealing is still more effective when the plastic sealing substance is present. The seal between the channel flanges and the panels is enhanced by the embedding of the upper edges of the former in the wood which forms the inner walls of the kerfs.
The described structure provides tight sealing tractor.
of the lateral joints and makes it possible to build tight roofs with a much flatter pitch than is practical with shingles.
Figures 6 and '7 illustrate the use of the panel joint when the roof is of such dimensions as to require a plurality of courses or panels. The panel 22 of the lower course is associated with a channel 23 in exactly the same manner as above described and, of course, channel 23 also receives the adjacent margin of a second panel, such as the panel ll of Figure 4. The upper margins of the panels of the lower course are lapped a suitable distance by the lower marginal portions of panels 24 and 25, which are associated with a channel 26 in the manner heretofore described. A wedge-shaped filler strip 21, which may conveniently be a shingle, is interposed between the top of the rafter 28 and that portion of the upper course immediately above the lower course of panels, in the manner particularly shown in Figure 6, so that undue flexing or bowing of the panels 2 5 and 25 when they are nailed to the rafter is prevented.
The suitability of plywood panels glued with waterproof glue and finished with a weather resistant coating for this type of construction will be readily apparent. Plywood has the unique feature of being notably resistant to the splitting effect of nails driven close to an edge. In the present invention the edge of the panel has to be further weakened by the groove which cuts approximately half way through its thickness and is spaced ordinarily with the center of the groove only about away from the edge. Notwithstanding that the nails are driven quite close to the panel edge and the further presence of the channel groove, the great strength of plywood is fully adequate for this severe treatment. I have had no trouble whatever with the edge splitting away as would certainly be the case if an attempt were made to use for this purpose either solid lumber or composition panels lacking the cross ply feature of plywood.
The great resistance to splitting and edge injury of plywood panels used according to the present invention also permits more than a single use of such a roof. I have found in practice that a particular advantage of the invention is that it permits temporary buildings, such as contractors construction camps, to be roofed quickly and cheaply with plywood and, then when the construction job is finished, the nails holding the panels to the roof can be drawn and the panels removed intact and used again satisfactorily on the same or a similar building erected somewhere else. This is a substantial economy to the con- In the first place, such buildings have to be built and closed in rapidly and the speed with which the roof can be covered by my new method is very advantageous. Also, a considerable part of a large contractors expense on a construction job lies in the losses connected with such temporary buildings, and to be able to salvage all the roof panels and use them again is quite an important economy.
Obviously, also, this roofing method may often be used to advantage in roofing and siding buildings of permanent character. Again, the speed and economy of the method and the tightness of the joints is equally advantageous. In such structures, in order to obtain a heavier and warmer roof, tight board sheathing may be laid under the plywood and in that case, the location of the joint may be disregarded and the plywood be nailed to the roof boards instead of to the,
panels extending side by side and having marginal projecting away from the latter, a pair of plywood kerfs receiving said flanges, the depth of said kerfs being less than the height of said flanges, a water-resistant plastic roofing compound in said channel and covering the web of the latter, and nails driven through the adjacent panel marginsand the channel member and securing said margins and member to the support and causing the edgesoi said flanges to be embedded in the end Wallsof the kerfs, said compound sealing the 10 nail holes in the panel Web.
' ERWIN A. HORN.