Patent GB-525413-A (GB)
Title: Improvements in or relating to the construction of fibre boards or like building boards and their fixture in situ
IPC: D21J1/16
Filed: 1939-02-18
Abstract: 525,413. Wall and ceiling linings. HAY, H. M. Feb. 18, 1939, Nos. 5504 and 6904. [Class 20 (iv)] Relates to the edge reinforcement and erection of " low-density " fibre building boards or sheets. According to the invention edge reinforcement is applied to the boards by invisible nails or staples during manufacture, or in the course of erection, and the exposure of wide metal securing strips on the exposed surfaces of the boards is avoided. The board a shown in Fig. 1 is stiffened by a metal strip b which is nailed or stitched by staples c to the edge of the board. This strip may project beyond one or both surfaces of the board, and the projecting edge f, Fig. 3, on the front face of the board may be rolled or bent over the flat edge strip b of the adjacent board to give a neat appearance at the joint or to act as a retaining hook for the edge of the adjacent board. Alternatively, the projecting edges of the strips of adjacent boards may both be rolled over either inwardly or outwardly. The metal strip b may be of angle form as shown in Fig. 2, or of Z section as shown in Fig. 5, wherein one flange e is secured to the back of the board a<SP>1</SP> and the other flange k provides a support for the edge of the board a<SP>2</SP>; in the latter case, the strip may be first secured to the purlin or other support P, and the board a<SP>1</SP> be then fastened by pins driven into the web of the strip, the other board a<SP>2</SP> being supported by the flange k. The flange e of the strip shown in Fig. 5 may be omitted, the web b being pinned to the edge of the board a<SP>1</SP>. Where the strip b has a rear flange, the latter may be used for fastening the strip to the purlin P by screws or clip plates. In another arrangement, the edges of the boards may,be pinned together by double-ended pins or spikes driven through the strip b into the edge of one board a before or after erection, the adjacent board being then pressed on the projecting pins or spikes; the strip b may have pins projecting alternately on opposite sides for engaging the boards. In another arrangement, outward movement of the boards is prevented by pins passing through a projecting portion of the strip b and inward movement is prevented by Z-shaped pins, one prong of which is driven into the edge of one board and the other prong extends over the inner surface of the adjacent board. Strips of I cross-section, Fig. 10, may be used having narrow flanges and secured to the boards by pins c<SP>1</SP> which are either double-pointed or project alternately in opposite directions through the strip ; alternatively, the edge reinforcement may be in the form of a shallow channel strip fastened by pins into the edge of the board. The reinforcing strip may be provided not only along the longitudinal edges, but along the transverse edges of the board, the strips being either independent or welded or otherwise secured together. Boards having reinforced edges may be rested on the roof purlins or like members before the roof covering is positioned, spacing strips of fibre or the like being laid on the purlins to prevent metallic contact between the strips b and the purlins ; alternatively, the strips b may be recessed where the sheets cross purlins to prevent such contact. When the purlins are of steel, the boards may be secured to wooden blocks which hang from the purlins by hook bolts. Stepped ceilings or recessed panel effects may be attained by utilizing flat strips b in the manner shown in Fig. 8, or by using Z-strips, the flanges of which form the edgereinforcements of the stepped boards a', a<SP>2</SP>. Other modifications are described in the first and second Provisional Specifications.