LINTELS

Abstract: A lintel (11) for block and brick walls with pins, posts or stops (14, 28, 29) to project into perpends of the course of bricks laid thereover. The pins might be in pairs (28, 29) and be associated with reinforcement (31, 39) in a lintel formed of concrete.

Description: Title; "LINTELS" BACKGROUND OF THE INVENTION (1) Field of the Invention THIS INVENTION relates to lintels and, in particular, to lintels made of concrete and the like. (2) Prior Art Lintels of various kinds are used in brick walls to continue brickwork over the top of doors and windows. Commonly the lintel is a length of angle iron with the iron overlapped at its ends over the top of the course of bricks at each side of a window or door opening which finishes at the upper level of the door or window. A variation of this style of lintel is seen in US 4106247. The brickwork then continues with the next course extended over the iron lintel. In time such lintels are corroded particularly in environments such as at the seaside. Concrete lintels are used, but for these to have any long term stability against sagging, they must be large in cross-section and they are visually obvious within a brick wall unless specially treated with facing bricks. Large sectioned lintels in concrete are heavy and not readily handled on a building site. OBJECT OF THE INVENTION It is an object of the invention to provide a lintel which is basically relatively easy to handle on a building site and, in use, resists sagging and corrosion to a degree greater than hitherto possible. NATURE OF THE INVENTION The invention achieves its object by providing a lintel for spanning openings such as windows, doors and the like in a brick, block, or other like type wall comprising: an elongate body part sufficient in length to span the opening with an upper surface for the laying of courses of bricks, blocks, etc. thereover; characterised in that there is provided a plurality of upstanding pins, posts or stops arrayed along the length of the upper surface of the elongate body part; said pins, posts or stops being provided in a predetermined pattern for projection into the perpends between bricks or blocks laid, in use, over the lintel to resist shear induced by the bricks thereover. The term pins, posts or stops used herein is to be taken to encompass any member which projects from the surface of the lintel to project into the perpend between bricks thereover and provide resistance to shear. Thus pins, posts or stops (referred to for convenience simply as pins or posts with the intention that the broader function of a stop is to be read into the term) might have a variety of geometries so long as their shape is consistent with the need to project into a perpend and resist shear. A pin, post or stop might therefore have planar, plate form characteristics and still perform the invention by providing resistance to shear at the top of the lintel. The term bricks or blocks used herein is to include any block form construction wherein bricks or the like are laid in courses with perpends therebetween. Thus masonry and other block like constructions are encompassed by the invention where lintels are required to support the construction over openings. In use of the above defined lintels, the pins or posts inter-engage with the bricks therebetween and together with the weight of the courses above they enable resistance to sagging of the lintel. By this means the dimensions of the lintel may be reduced below what would be otherwise necessary in a concrete lintel able to resist sagging of the lintel under the weight of bricks above. It is believed that failure of a lintel without pins is in part associated with failure of the bond between lintel and bricks, which bond is especially likely to fail when a damp proofing membrane is used therebetween. The pins, posts or stops projected into perpends opposes the shear stresses associated with this failure. For a lintel to sag, the courses of bricks above it must slide outwards relative to the lintel. This outward movement exerts a force on the pins which is resisted by the pins. The tendency to move outwards is greatest towards the ends of the lintels and the force required to be resisted to prevent this movement is also greatest towards the ends of the lintel. To resist this force, the number of perpends supplied with pins or posts may be increased towards the ends of the lintels. Conversely, the weight of the wall above a lintel is believed to be loaded downwardly and outwardly so as to load the bricks sideways against the pins, posts or stops within the perpends between the bricks. This outward loading opposes the movement of the pins, posts or stops which would be required if the lintel is to sag. The weight of bricks over the lintel loads outwardly such that a greater load is applied against pins, posts or stops on the outer ends of the lintels and the number of perpends supplied with pins, posts or stops at the outer ends may be increased, or conversely, the number of pins or posts at the centre may be reduced. In one particular construction of the above defined lintel, at each perpend to receive a pin or post, the lintel may have two such pins or posts projected therefrom, established by U-shaped elements embedded in the lintel with their two arms projected therefrom. The U-shaped elements may be associated within the lintel with an elongate length of reinforcing rod embedded in the lintel as will become more clear below. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to various preferred embodiments as shown in the accompanying drawings, in which: FIG. 1 is an elevation of a part of a brick wall showing a lintel in accordance with the present invention set in place; FIG. 2 is a perspective section of a wall as in FIG. 1; FIG. 3 is a side elevation indicating a pattern of pins or posts which might be used on a lintel in accordance with the present invention in a wall of the type illustrated in FIG. 1; FIG. 4 is a side elevation of an alternate form for a lintel in accordance with the invention; FIG. 5 is a vertical section through a wall as in FIG. 2 showing details of a lintel in accordance with the present invention; and FIG. 6 is a transverse section through a lintel in accordance with the present invention showing a lintel in accordance with the invention in greater detail. PREFERRED EMBODIMENTS In FIG. 1, a brick wall 10 is provided with a lintel 11 (shown cross-patched) over an opening 13 in the wall 10. The lintel 11 may be a concrete lintel as described below. It may be reinforced internally with a length of reinforcement (not shown) embedded therein. The wall 10 may be a brick veneer wall in a standard form of dwelling. The preferred embodiments refer to brick veneer and cavity brick constructions using standard house bricks but the invention has application in respect of all forms of brick and block construction. The lintel is dimensioned with a cross-section which matches that of a single course of bricks so as to mate into the brickwork in a tidy fashion with an end which overlaps the lower course of bricks at the sides of the window as at 12 in FIG. 1. The length of the lintel is normally equal to an even number of bricks and mortar spacings therebetween. In its preferred form, the lintel of this invention is formed by concrete. In its usual form, it requires some tensile reinforcement or tensile strength. However, it will be clear to a man skilled in the art that the mechanics of the pins or posts to be described below will be realised no matter what the material of the lintel might be. Consequently, the invention should not be interpreted to be restricted to concrete. However, the ensuing description is with regard to the use of concrete. As stated above, the lintel is able to be used with brickwork, to support courses of bricks over doors, windows, and the like. In cavity brick constructions, a separate lintel can be used in each wall of the double wall of bricks, at the top of an opening to be spanned by further courses of bricks. FIG. 2 is a perspective view of a lintel 11 as in FIG. 1, at an end of the lintel. The lintel 11 has split bricks 38 applied thereto with mortar imitating spacings therebetween such that the lintel merges with the wall when installed. The lintel preferably has a reinforcement 39 extended through the material of the lintel. A damp proof membrane 40 can be used above the lintel and a sealant can be applied between the damp proof membrane 40 and a top surface of the lintel 11. In FIG. 3, the lintel 11 is shown as it would lie in place in wall 10 without a course of -bricks thereabove. This way, the pins or posts 14 can be seen. There may be pins or posts at each perpend to put a pin or post between every pair of adjoining bricks, or, various perpends may be left without pins. As described above, loading is downward and outward so that in the region 16, every second perpend might be provided with a pin or post, or no perpends (as will be described below) may need to be provided with pins, and every perpend in the regions 15 and 16 at the outer ends of the lintel 11 can be provided with pins. In a preferred form of a lintel of the type illustrated in FIG. 3, if the width of the opening is L then the centre region 16 width might be §L and the outer regions 15 and 17 might be equal in length. Other designs besides this are possible (see below). The length of the lintel will be longer to some considerable degree to load the weight above the lintel into the brickwork at each side of the opening. With standard brick dimensioned lintels, a 600 mm opening might be spanned by a 960 mm lintel. A 3600 mm opening by a 4080 mm lintel. To avoid sagging of the lintels, the longer lintels may require larger numbers of courses over them to provide sufficient total cross- section to resist sagging and to keep the shear stresses in the mortar joints and on the pins to an acceptable low level. For a 3600 mm opening a lintel of standard brick cross-section and the above described pin or post pattern, at least six courses of bricks will be likely to be required over the lintel to avoid its sagging. The number of courses steadily drops to two when the opening width is reduced to 2100 mm from the six at 3600 mm for lintels of the above type. In FIG. 4, the lintel 32 extends across a space between walls 33 and 34 with shear pins 35 as above except in this embodiment the centre 36 is free of shear pins. This is possible as the shear pins which are most called on in realising the effect of the invention are the outer shear pins, the ones towards the ends of the lintel. In FIG. 5, a roof truss 18 is shown over a timber wall 19 with a brick veneer wall 20 spaced therefrom over a lintel 21. The lintel 21 has a facing brick 22 attached thereto so that visually the lintel 21 is hidden and the wall 20 appears to be continuous down to the top of the opening over which lintel 21 extends. Pins or posts 23 extend into the perpends of the next course of bricks and wall 20 may be attached in the usual way by suitable connectors or brick ties 24 to frame 19 to bind the two elements of the wall. The wall 19 may be the usual load bearing stud wall. A damp proof membrane 37 may be fitted as shown. In FIG. 6, the lintel 25 in concrete has a row of facing bricks 26 applied thereto so that it merges into the wall when in place. The upper surface 27 has an array of pins or posts therealong at chosen intervals and at each interval, the pins or posts may be U- shaped elements 30 with their arms 28 and 29 projected out of the upper surface to a degree which puts their ends into the perpends of a course laid thereover. The U-shaped elements 30 may be attached to a length of reinforcement 31 inserted into the lintel at its formation. The U-shaped elements and the reinforcement may be welded together as a prefabricated assembly which is held within the concrete of the lintel as the concrete sets in a suitable mould. Of course, other shapes besides U-shapes might be used. Pairs of vertical pins are not the only geometry which could be used. Single pins, loops and multiple posts might project into a perpend so long as the resistance to shear forces exerted by the courses over the lintel exist. The pins may be eight gauge galvanised rod. The reinforcement might be a length of galvanised Y16 rod. A welded assembly of rod stock to form reinforcement and pins or posts is best galvanised after welding for maximum anti-corrosive properties. The concrete lintel is typically 85 mm deep with rod 31 set 40 mm therein from the top. The concrete lintel might be 97 mm wide with a 20 mm facing brick set 7 mm therein at a front face to duplicate full width brick. It will be clear to those skilled in the art that the dimensions will vary to suit the application and particularly the nature of the bricks or blocks being laid. The dimensions herein are likely with conventional bricks. Use of the above described lintel has advantages over standard lintels such as improved fire rating in addition to sag resistance and corrosion resistence. Performance of the lintel is enhanced in usuage such as in FIG. 2 by the provision of weep holes in the mortar above the damp proof membrane to enable drainage of moisture otherwise trapped above the membrane.

Claims: CLAIMS 1. A lintel for spanning openings such as windows, doors and the like in a brick, block, or other like type walls comprising: an elongate body part sufficient in length to span the opening with an upper surface for the laying of courses of bricks, blocks, etc. thereover; characterised in that there is a plurality of upstanding pins, posts or stops arrayed along the length of the upper surface of the elongate body part; said pins, posts or stops being provided in a predetermined pattern for projection into the perpends between bricks or blocks laid, in use, over the lintel to resist shear induced by the bricks thereover. 2. A lintel as claimed in Claim 1 wherein: said elongate body part is uniform in cross- section therealong, with a cross-section matching that of a course of bricks or blocks. 3. A lintel as claimed in Claim 1 wherein: said pins, posts or stops are in spaced apart pairs, each pin, post or stop of a pair extending, in use, into the same perpend. 4. A lintel as claimed in Claim 1 wherein: the number of pins, posts or stops per unit length of the lintel is reduced at the centre thereof as compared with its ends. 5. A lintel as claimed in Claim 4 wherein: the centre of the lintel is free of pins, posts or stops over a length equal to a multiple of bricks, and enough pins, posts or stops exist at each side thereof to project into every perpend outside the pin, post or stop free centre region. 6. A lintel as claimed in Claim 1 wherein: said elongate body part is concrete. 7. A lintel as claimed in Claim 6 wherein: reinforcement extends internally through the elongate length of the body part, and the pins, posts or stops are steel rod-form elements attached thereto. 8. A lintel as claimed in Claim 7 wherein: the pins, posts or stops are established by the arms of a generally U-shaped element embedded in the elongate body part with the upper arm ends of the generally U-shaped elements projecting therefrom. 9. A lintel as claimed inr Claim 1 wherein: the face thereof which is oriented outwardly, in use, is provided with brick tiles to duplicate a course of bricks and match those of a wall incorporating the lintel. 10. A lintel as claimed in Claim 2 wherein: the number of pins, posts or stops per unit length of the lintel is reduced at the centre thereof as compared with its ends. 11. A lintel as claimed in Claim 10 wherein: the centre of the lintel is free of pins, posts or stops over a length equal to a multiple or bricks, and enough pins, posts or stops exist at each side thereof to project into every perpend outside the pin, post or stop free region. 12. A lintel as claimed in Claim 9 wherein: said pins, posts or stops are in spaced apart pairs, each pin, post or stop of a pair extends, in use, into the same perpend. 13. A lintel as claimed in Claim 12 wherein: the number of pairs per unit length is reduced at the centre of the lintel as compared with its ends. 14. A lintel as claimed in Claim 13 wherein the centre of the lintel is free of said pairs over a length equal to a multiple of bricks, and enough pairs exist at each side thereof to project into every perpend outside the pair free centre region. 15. A lintel as claimed in Claim 14 wherein the elongate body part is concrete. 26. A lintel as claimed in Claim 15 wherein: reinforcement extends internally through the body part and the pairs are the arms of U-shaped elements embedded in the body part with the ends of the U-shaped element's arms projected therefrom.

Inventors: BERGER VICTOR, BERGER, VICTOR
Applicants: BERGER LINTELS INT, BERGER VICTOR, BERGER LINTELS INTERNATIONAL PTY LTD
Application year: 1993
Main classification: E04C3
IPC codes: E04C3