IE970314A1 - Thermal gaskets for lintels - Google Patents

Abstract

A thermal gasket (10) which comprises a solid aperture-free sheet of impervious material to be positioned between an undersurface of a lintel (1) and a supporting structure (9) therefore. The gasket (10) includes a plurality of upstanding spacers on which the lintel (1) is supported whereby an air gap (17) is defined between the opposed surfaces of the impervious sheet and the lintel (1).<Fig.1>

Description

THERMAL BASKETS FOR LINTELS This invention relates to thermal gaskets for use with lintels.

Conventional metal lintels can define flow paths for heat passing from the interior to the exterior of a building when placed in direct contact with a plaster or mortar course adjoining an exterior wall of the building, and promote cold spots on or close to such exterior walls.

Lintels which include some form of adhesion enhancing means for mortar are known, one such lintel being disclosed in GB-A-2258255. This document discloses a lintel assembly which includes a sheet of preformed plastics material for attachment to the underside of a section of a lintel, the sheet having a plurality of holes and spacing legs which define recesses for accommodating mortar. The gaps are either filled with mortar or open OPEN TO PUBLIC INSPECTION UNDER SECTION 28 ANO RULE 23 jnl (to /«z-S or sided. The sheets therefore also define flow paths for heat passing from the interior to the exterior of a building.

It is an object of this invention to provide a thermal gasket for use with a lintel which significantly reduces the out-flow of heat from a building and the presence of cold spots.

According to the present invention in one aspect there is provided a thermal gasket which comprises a sheet of impervious aperture-free material to be positioned between an undersurface of a lintel and a supporting structure therefore, the gasket comprising a solid sheet and including a plurality of upstanding spacers on which the lintel is supported whereby an air gap closed on its upper and lower surfaces is defined between the opposed surfaces of the impervious sheet and the lintel.

The spacers may be formed integrally with the sheet of impervious material and may comprise a series of discrete protrusions or ridges which extend along the entire length and/or width of the gasket. Alternatively, the spacers may be separable from the gasket and may selectively be positioned thereon. The gasket may be produced from a plastics material and may comprise an extruded sheet. A suitable plastics material comprises UPVC. Other suitable materials may however be employed.

The surface of the gasket which is intended to lie immediately below the undersurface of the lintel may be coated with or include a reflective material or a material having a reflective finish further to reduce heat losses.

The under surface of the gasket may include one or more keying elements which act to key the gasket to a course of plaster or other material on which the gasket is to be positioned.

A quantity of intumescent material may be provided to ensure that the spacing between the undersurface of the lintel and its support is maintained in the event of a fire. This intumescent material may form part of the spacers.

In another aspect, the invention provides a thermal gasket for use with a lintel, the gasket taking the form of a solid sheet of semi-rigid or rigid material from whose upper surface protrudes a plurality of spacers on which a lintel is to be supported and from whose under surface protrudes a plurality of keying members, the spacers defining with the opposed surface of the gasket and the lintel one or more air gaps which are closed on their upper and lower surfaces and operate to insulate the lintel thermally.

In a further aspect, there is provided, in combination, a lintel and a thermal gasket, the gasket comprising a solid sheet of plastics material from whose upper surface protrudes in plurality of spacers and from whose lower surface protrudes a plurality of keying members, the gasket being shaped and dimensioned to clip onto the lintel with the lintel underside supported on the spacers of the gasket.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: Figure 1 is a side view in section of a lintel and thermal gasket in accordance with the invention; and Figure 2 and 3 are respectively side and plan views from above of the thermal gasket illustrated in Figure 1 to an enlarged scale.

Figure 1 shows a steel lintel 1 positioned between an outer wall 2 and inner wall 3 of a building. As shown, the lintel has a outwardly extending section 5, a bridge section 6 in which the insulation is positioned, and an inwardly extending section 7. A quantity of insulation material 4 is positioned within the profile of the bridge section 6 of the lintel.

A thermal gasket 10 in accordance with the invention is shown positioned between the undersurface of the inwardly extending section 7 of the lintel and the plaster course 9. The gasket 10 is produced from a solid relatively rigid impervious aperture-free sheet of, for example, plastics and is formed at its inwardly extending end with a clip 11 into which the inwardly extending end of the lintel section 7 protrudes with the edges of the clip engaging the opposite sides of the lintel section. The end of the gasket remote from the clip 11 is turned upwardly generally through a right angle and engages an adjoining surface of the bridge section 6 of the lintel.

The gasket 10 is in solid sheet form and extends along the entire length of the lintel. Alternatively, more than one gasket 10 may be provided, each in side-by-side contact with the neighbouring gasket or gaskets. Means may be provided for connecting neighbouring gaskets together. Engagement of the gasket end 12 and clip 11 with the lintel section 7 enables the gasket to be assembled onto the lintel for ease of use.

The insulation material 4 is recessed at 14 for ease of assembly of the gasket to the lintel.

Upstanding from the upper surface 15 of the thermal gasket are a plurality of lengthwise extending ridges 16 which define spacers on which the lintel 1 is supported. Thus, one or more air gaps 17 are defined between the opposed surfaces of the lintel 1 and the gasket 10, each such air gap being closed on its upper and lower surfaces by the opposed 20 undersurface of the lintel section 7 and the solid floor of the gasket 10. In this construction, the gasket 10 may be extruded and cut to length. In an alternative arrangement the spacers take the form of a series of discrete protrusions which may or may not be formed integrally with the gasket.

In the latter case, the spacers are selectively positioned on the gasket surface before the lintel is placed in position. As before, the air gap formed by the spaces in closed on its upper and lower surfaces by the opposed undersurface of the lintel section and the solid floor of the gasket.

On its underside the gasket 10 includes a plurality of keying members 18 which serve to key the gasket to the plaster course. These keying members may take any conventional form.

Typically, the thickness of the gasket 10 is of the order of 1.5mm (a typical range of thicknesses being from 0.5 to 5mm); the return of the clip is typically 17.4mm (a typical range being between 15 and 20mm); the height of the gasket end 12 is typically 38mm (a typical range being between 0 and 50mm); the width of spacer is typically 3mm (a typical range being between 1 and 5mm); and the spacing between neighbouring spacers is typically between 28.8mm (a typical range being between 20 and 40mm).

The upper surface of the gasket may be coated or include a reflective or suitably coloured material to reduce heat losses further.

A quantity of intumescent material may be positioned on or between the opposed surfaces of the lintel and the gasket to ensure the integrity of 20 the gap in the event of a fire. This intumescent may conveniently be coated on or incorporated in the spacers.

Typically, the gasket is produced from a UPVC material having one or more of the following: a density of 1.45, a shore hardness of between D65-D85, a coefficient of linear expansion of 7-8 10-5°C-1, a thermal conductivity of 0.16 W/M°C, a vicat softening point of 78°C, a tensile strength of 42.0 mpc, TO a flexual strength of 28.0 mpc, and an impact strength at 23°C of 6.29 kjm'? and at -10°C 3.52 kjm2.

In use, the thermal gasket and the air gap defined thereby present a barrier to heat seeking to leave the building interior. Thus, the normal thermal flow paths via the lintel are inhibited by the gasket and the air gap and/or by the insulation 4. Also, the onset of cold spots often found in buildings is significantly reduced.

It will be appreciated that the foregoing is merely exemplary of thermal gaskets in accordance with the invention and that modifications can readily be made thereto without departing from the scope of the invention as set out in the appended claims.

Claims (5)

CLAIMS 1. ° quantity of intumescent material. 9. A thermal gasket for use with a lintel, the gasket taking the form of a solid sheet of semi-rigid or rigid material from whose upper surface protrudes a plurality of spacers on which a lintel is to be supported and from whose under surface protrudes a plurality of keying 15 members, the spacers defining with the opposed surface of the gasket and the lintel one or more air gaps which are closed on their upper and lower surfaces and operate to insulate the lintel thermally. 10. In combination, a lintel and a thermal gasket, the gasket comprising 20 a solid sheet of plastics material from whose upper surface protrudes in plurality of spacers and from whose lower surface protrudes a plurality of keying members, the gasket being shaped and dimensioned to clip onto the lintel with the lintel underside supported on the spacers of the gasket.

1. A thermal gasket which comprises a sheet of impervious aperturefree material to be positioned between an undersurface of a lintel and a supporting structure therefore, the gasket comprising a solid 5 sheet and including a plurality of upstanding spacers on which the lintel is supported whereby an air gap closed on its upper and lower surfaces is defined between the opposed surfaces of the impervious sheet and the lintel.

2. A gasket as claimed in claim 1 wherein the spacers are formed 10 integrally with the sheet of impervious material.

3. A gasket as claimed in claim 1 or claim 2 comprising a series of discrete protrusions or ridges which extend along the entire length and/or width of the gasket.

4. A gasket as claimed in claim 1 or claim 3 when dependent on claim 1 15 wherein the spacers are separable from the gasket. 5. A gasket as claimed in any one of claims 1 to 4 produced from an extruded sheet of plastics material. 6. A gasket as claimed in any one of the preceding claims whose surface which is intended to lie immediately below the undersurface of a lintel is coated with or includes a reflective material or a material having a reflective finish. 5 7. A gasket as claimed in any one of the preceding claims whose under surface includes one or more keying elements which act to key the gasket to a course of plaster or other material on which the gasket is to be positioned. 8. A gasket as claimed in any one of the preceding claims including a

5. 11. A thermal gasket substantially as herein described and as described with reference to Figures 1 to 3 of the accompanying drawings.