US1995393A - Self-furring plaster board - Google Patents

Description

March 26, 1935. F. A. MANSKE SELF FURRING PLASTER BOARD 2 Sheets-$heet 1 Filed March 15, 1933 A ga m xux 5'1 lNV ENTOR FEED/I-MFINSKE.

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March 26, 1935. F. A. MANSKE SELF FURRING PLASTER BOARD Filed March 15, 1933 Patented Mar. 26, 1935 UNITED STATES PATENT OFFICE 1,995,393 SELF-FURRING PLASTER BOARD Fred A. Manske, Chicago, Ill., assignor to United States Gypsum Company, Chicago, 111., a corporation of Illinois Application March 15, 1933, Serial No. 660,805 Claims. (Cl. 72-124) This invention relates to articles of manufac- Fig. 1 is a perspective view of one end of my ture used in building constructions, and has refimproved plaster board, erence more particularly to self-furring plaster Fig. 2 is a fragmentary face elevation of a secboards to be used as a base for a coating of plastion of a wall with parts broken away to disclose 6 ter. the construction,

In the erection of the plastered walls of a build- Fig. 3 is a transverse sectional view through the ing, it is standard practice to use flat plaster wall construction, boards as a base for the plaster coat. The plas- Fig. 4 is a vertical sectional view through a ter boards are commonly nailed to wooden studs .wall adjacent a stud,

with their edges lying in abutting relation to form Fig. 5 is a sectional elevation through two of 10 board joints. One of the difficulties experienced my improved plaster .boards in nested relation, in this type of construction, is thatthe plasterer Figs. 6 and '7 are face views of modified forms has a tendency to apply too thin a layer of plasof perforated plaster board,

ter over the faces of the flat boards. As a result Fig. 8 is a transverse sectional view through an of this economizing on plaster, the wall over the imperforate plaster board with projections, 15

board joints is weak, and cracks are apt to form Fig. 9 is a transverse sectional view through a in the plaster due, for example, to stresses in supfurther modified form of plaster board,

porting framework and foundations. In the past, Fig. 10 is a fragmentary plan view of a modified it has also been customary to depend on the adform of board with spot grounds, and

hesion between the plaster and the paper cover Figs. 11 and 12 are fragmentary sectional views 20 sheet to hold the layer of plaster in position on through modified forms of plaster board.

the wall. However, under certain conditions, The improved plasterboard comprises a core 12 such as in the case of fire, the plaster layer sepof cementitious material, such as a composition arates from the plaster board and the wall fails composed largely of gypsum together with other prematurely as a result. In the manufacture of ingredients such as vegetable fiber, foam, etc. A 25 the fiat plaster boards, the cost of drying is abrear paper cover sheet 13 is applied to one face of normally high as the steam from the core mathe core 12 during the manufacture of the plaster terial cannot pass freely through the imperforate board, and a front .paper cover sheet 14 is applied cover sheets as the board passes through the dryto the other face of the core 12. The cover sheet i0 ing n- 14 is preferably folded about one edge of the core An object of this invention therefore, is to pro- 12 and has a flap 15 which is adhesively attached Vide a Plaster board av p t grounds or furto the inner edge of cover sheet 13. While a prering D J'e 0n t front ac or the purferred type of board has been described, the term D e o f rc g the plasterer to apply the p oper plaster board should be construed generically thickness o p as a thus e s the plObto include other desirable types of building board. abil ty f C ac g of h plaster. One of the salient features of the invention con- An th r o j t f th nv nt s t p vid a sists in forming the board at spaced points while plaster o rd h v n keying p n n ja n still in a plastic state, to provide rounded spot the furrin pr j t n s ha h p ast lay grounds, nodes, projections or protuberances 16 will be fi mly a d m an a y t d o he on the front face of the board and mating roundplaster ed hollows 1'7 on the rear face of the board. The

Another obje of the mventlon 15 to provide a projections 16 on the face of the board are joined plaster board which has a lower cost of manufact0 the plane fa e f the board by gentle curves tulje as a result of decreased drymg tune less 18 so as not to interfere with the edge of a trowel Welght per square foot as the plasterer applies a layer of plaster 19 to the A further object of the invention is to provide a Se1f furring plaster board in which the face of the board. In forming the nodes 16, the

forming dies are shaped to provide a radius of tuberances of one boardwill nest into the protuberances of an adjoining b t p the hollow Somewhat less than the radius of ting shipment of the boards as bundled units; the node 16 thus producing space 20 between also to improve plaster boards in other respect the hollows and nodes when the boards are nested hereinafter specified and claimed, (Fig. 5). This arrangement permits easier nest- Reference is to be had to the accompanying ing of the boards When y are sec red face to drawings forming a part of this specification, in face in bundles for shipment. The nodes are prefwhich erably arranged in staggered relation (Figs. 1 and Val 2) but they may also be spaced in rectangular relation (Figs. 6 and 7).

All or some of the nodes 16 are preferably provided with a keying hole 21, so that when the plaster layer 19 is applied to the face of the board, a portion of the plaster will pass through the hole and form a bonding key 22 at the back of the board, thus materially increasing the fire resistance of the finished wall by preventing the plaster layer from breaking loose from the face of the board. The staggered relation of the nodes and hole is preferred as this staggered relation permits good bond of the plaster to the board, regardless of the position of a stud 23 to which the boards are secured by nails 24. Only a few of the holes will lie over the stud with the staggered arrangement and even with these holes, the plaster has ample space to form the keys 22 between the hollows 17 and the stud 23. After the scratch or base coat plaster 19 has been applied and dried, the second or browning coat of plaster 25 and finishing coat plaster 26 are applied in the usual way to form the finished wall structure. If desired, the holes 21 may be omitted, thus producing a board as shown in Fig. 8 with projecting nodes on the front face of the board which will insure the application of a reasonably thick coat of plaster. In the form of the invention shown in Fig. 9, spot grounds or nodes 28 are provided on the front face of the board, the hollows 1'7 being omitted leaving the back face of the board flat. Each of the nodes 28 has a keying perforation 29 as previously described in connection with the other forms of the board. In the modified form of the board shown in Fig. 10, only about two spot grounds or nodes 30 are used on the face of the board. If the board size is 16 inches by 48 inches, these two spot grounds preferably divide the board into three equal 16 inch spaces. A red or other colored marking line or indicator 31 may be provided across the rounded surface of each node 30 to indicate the position of the stud to the workman who nails the boards to the studs, the studs being commonly placed on 16 inch centers. The indicator line 31 may also indicate to the workman where aboard may be cut when breaking joints between boards, in order to secure the best possible arrangement.

In the modified form of board shown in Fig. 11, the back face of the board 33 is provided with hollows 34 and a keying hole 35 passes through the board in each of said hollows 34. The front face 36 of the board is coated with a layer of plaster 37 which passes through the hole 35 and forms a key 38 in the hollow 34. In this form of board, the hollow 34 permits the plaster key 3'? to form, even if the hollow is located directly over a stud.

The modified form of board shown in Fig. 12 has a smooth front surface 39 and a rear surface 40 which has hollows 41. Holes 42 are formed in the board in each of the hollows 41 by the use of a four cornered pointed punch so that the rear paper cover sheet forms outwardly extending flaps 43 which partially protects and reinforces the core of the board inside the holes 42. The paper cover sheet on the front face of the board forms fiaps 44 which curl outwardly to form spot grounds on the front face of the board, thus insuring the application of a suificiently thick layer of plaster to the front face of the board.

In manufacturing an improved board, such as that shown in Figs. 1 and 2, a standard board machine is used in a manner well known to the art.

Such a machine delivers the plastic core material 12 between the cover sheets 13 and 14. After the wet board has passed along the machine for a period sufficient to permit the core material to approach its setting point, the board is engaged by opposed chains of male and female dies which act on the two cover sheets to form the nodes 16 and hollows 1'7 into the boards just before the setting of the board core 12. The dies then disengage from the board and shortly after setting of the core 12, punches travel with the board a short distance and then return, to punch the holes 21 through the board at the nodes desired to perforate. Instead of punching the holes in the boards while wet, the boards with the formed nodes may be dried and bundled, the holes being drilled through the bundle of boards at the nodes by multiple spindle drills or the like.

My improved plaster board presents many advantages over the standard type of imperforate, flat boards and the following might be mentioned;

1. The board is self-furring thus insuring a proper thickness of plaster over the board and reducing cracking of the plaster.

2. The perforated board provides a strong mechanical key for the plaster, even when the perforations are positioned directly over the stud. thus insuring a high fire resistance in a wall and preventing separation of the plaster from the board. A one hour fire rating can be obtained with my improved perforated board.

3. The perforations in the board cover sheets permit faster drying at a lower cost due to the freer passage of moisture.

4. The improved board is easy studs and is easy to plaster over.

5. The board is lighter in weight thus reducing freight costs and providing easier handling by the workman.

6. The boards nest readily for bundling preparatory to shipment.

'I. The board is strengthened by the reinforcing action of the nodes thus permitting the use of thinner cover sheets, a thinner core or both, with the same final strength of board.

8. The improved board provides better walls and ceilings in a building.

While I have described my invention as particularly applicable to plaster boards with cementitious cores and paper cover sheets, other types of panels or plaster boards, such as those made of fiber, may be used if desired.

I would state in conclusion that, while the illustrated examples constitute certain examples of the invention, I do not wish to limit myself precisely to these details, since manifestly the same may be considerably varied without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. An article of manufacture comprising a plaster board having paper cover sheets and having projecting nodes on the front face of said board and mating 'arcuate hollows on the rear face of said board, said board being provided with a hole through said board at a plurality of said nodes so as to permit plaster applied to said front face to pass through said hole and form a key in a hollow without extending substantially beyond the rear face of said board.

2. An article of manufacture comprising a plaster board having a cementitious core and paper cover sheets, said board having nodes proto apply to the jecting from the front surface of said board to provide spot grounds to insure the application of a thick layer of plaster to said front face, said board having mating hollows on the rear face thereof to permit nesting during shipment one of said nodes having a hole passing through said board, the punched flaps of one of said cover sheets being pressed inwardly and bonded to said core so as to reinforce said board around the periphery of said hole;

3. An article of manufacture comprising a plaster board having spaced rounded nodes on one face and mating rounded hollows on the otherface of said board, the radii of said nodes and hollows being different to provide nesting ability to said boards.

4. A building construction comprising a building frame, plaster boards secured to said frame,

said boards having displaced hollows positioned over said frame and mating nodes projecting from the front face of said board, one or more of said nodes being provided with a keying hole to permit plaster applied to the front face of said board to pass through said hole and form a key in said hollow and in front of said frame.

5. A building construction comprising a building frame, plaster board secured to said frame, said board having displaced hollows at spaced intervals, at least certain of said hollows extending over said frame, and keying apertures passing completely through said board and through at least some of said hollows, the apertured hol- 10Ws over said frame permitting substantial plaster keys to be formed at the back of the board adjacent said frame.

FRED A. MANSKE.

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