GB2263290A - Adjusting roof pitch in glazed structures - Google Patents

Abstract

A pitched roof structure, e.g. a conservatory, comprising a ridge element, a beam 1 extending substantially horizontally along the eave of the roof, and a plurality of inclined rafters 7 extending from the ridge element to the inner face of the beam and supporting roofing panels 10 or the like which contact the beam 1 at the upper edge of its outer face, wherein the inner face of the beam provides a plurality of upwardly facing locating surfaces on which the rafters 7 may rest, the vertical spacing of the locating surfaces being such that different angles of inclination of the rafters are accommodated by selecting the appropriate locating surfaces on which to rest the rafter-end. A flange 5, 6, may support an asymmetrical body 14, which as shown, supports beam at angle A, but when inverted (face 16 upward) supports a beam at a different angle. Alternatively spacers of different thickness may be used; the fitting may be on the rafter rather than the beam. A ventilation method is described. <IMAGE>

Description

GLAZED STRUCTURES The present invention relates to glazed structures, and is particularly concerned with supporting frameworks of glazed structures wherein roofs of a number of different pitches may be constructed using substantially identical components. The specification also provides for the ventilation of glazed roofing structures.

In the construction of structures such as conservatories, and in particular conservatories having pitched roofs with a ridge and a gable end, it is conventional practice to provide a horizontal beam extending along the top of the vertical sidewalls of the structure, the outer ends of the inclined rafters forming the roof resting on top of this horizontal beam.

Due to the inclination of the rafters, the point of contact between the rafter and the horizontal beam is necessarily at the outside face of the building, and thus a 'cold bridge' from within the building to the outside is created. This effect is particularly marked when the rafters and beams are constructed from extruded aluminium.

The present invention seeks to provide a structure wherein aluminium may be used for the rafters and horizontal beam of a conservatory type structure, without any 'cold bridge' being formed, and which may use essentially the same extruded sections to form roofs having a number of different pitch angles.

An embodiment of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is a section, taken in a vertical plane, showing the cross-section of a ring beam and its attachment to a rafter; Figure la is an enlarged perspective view of a component of the structure of Figure 1; Figure 2 is a view similar to Figure 1, illustrating the arrangement of components to accommodate a different roof pitch angle; Figure 3 is a sectional view of a ring beam with a ventilator installed; and Figure 4 shows a cross-sectional view of a ring beam with an alternative ventilating arrangement.

Referring to Figures 1 and 2, a box-section ring beam 1 is shown, the ring being constituted by two 'C' shaped sections 2 and 3, joined by insulating resin material 4 to form a rectangular-section beam 1. The 'C' section 3, which when installed faces towards the inside of the building, is formed with an 'L' shaped flange, the flange having a first web 5 extending horizontally from the section 3 and a second flange 6 extending vertically from the free end of flange 5.

In order to form a roof of pitch angle A, seen in Figure 1, a rafter 7, which is preferably a hollow extruded aluminium component, is shaped so that its end face 8 is vertical when the rafter 7 is at the required roof pitch angle A. In the embodiment shown, the rafter 7 has attached to its upper surface a glazing section 9 for securing the glazing material 10. Preferably, the glazing section 9 is of insulating plastics material and includes an upstanding web which extends vertically between adjacent glazing panels 10, to engage a retaining clip (not shown) which bears downwardly on the upper surface of the glazing panels 10 to retain them in position.

In order to ensure a draft free sealing of the structure at the outer edge of the ring beam 1, the rafter 7 has to be attached to the inner face of the ring beam 1 at a height such that its upper surface carrying the glazing section 9 is in alignment with the outer upper edge of the ring beam 1.

To attach a box-section rafter 7 to the ring beam 1, a block 11 of rigid insulating material is shaped so as to correspond with the internal dimensions of the rafter 7, and is formed with a bore 12 to accept a fixing screw 13. The screw 13 is intended merely as a locating element, rather than a stress-bearing fixing, since the vertical downward force on the rafter 7 is transmitted to the ring beam 1 by means of a locating block 14. It is also foreseen that the rafter may be a solid 'I' section, and in this case the block 11 will preferably include a recess to receive the end of the rafter, or a clevis-type bracket may be used.

The locating stop 14 is shown in greater detail in Figure la, and comprises a block having bevelled end surfaces 15 and 16, a substantially planar front surface 17 and a rear face 18. Extending across the rear face 18 is an undercut slot 19 of substantially 'T' cross-section, the throat dimension 'T' of the slot being sufficiently wide to allow the piece 14 to be placed over the webs 5 and 6 of the flange in the 'C' section 3 of the ring beam 1, and to be held in place by a hooking action. It will be noted, by comparing Figures 1 and 2, that the 'T' shaped slot is not formed centrally in the rear face 18 of the block 14. The reason for this will become apparent later in the description.

The angles of the bevelled end faces 15 and 16 are selected so that, when the block 14 engages the flanges 5 and 6 of the ring beam 1, the uppermost of the bevelled surfaces 15 or 16 is inclined at the angle required for the close engagement of the bevelled surface with the underside of a rafter 7.

In order to construct roofs of different pitches, the end faces 8 of the rafters 7 must be fixed to the ring beam 1 at differing heights relative to the ring beam, in order that the plane of the upper surface of the rafter 7, when extended, should intersect the upper outer corner of the ring beam. The locating block 14 is dimensioned so that, when in position with its slot 19 in engagement with the flange of the ring beam 1, its uppermost face 15 or 16 is positioned at the correct height in relation to the ring beam 1 to locate the rafter 7 relative to the ring beam 1.

With the illustrated structure, no 'cold bridge' from the interior to the exterior of the building exists, since there are no continuous paths through the metallic components for heat to escape.

In alternative embodiments of the structure, the face of the ring beam 1 may be formed with a step rather than with a flange, to provide an upwardly facing surface to locate the rafter end. The step may be provided at a height suitable for the rafter to bear directly on the face when a roof of the steepest pitch is being constructed. For shallower roof pitches, packing blocks of preselected size will be interposed between the rafter and the step surface to support the rafter end.

As a further alternative, the ring beams 1 may be formed with a re-entrant channel in its vertical face exposed to the interior of the building, and a suitably formed support block may engage in the channel to support the rafter end. Such a block may, like the block 14 of Figures 1, la and 2, be reversible to provide a number of alternative roof pitches using the same components.

As a further alternative, the insulating block 11 which is received in the rafter end may be shaped so as to provide a downwardly facing surface to locate the rafter in height by engaging the upper surface of the ring beam.

Referring now to Figure 3, there is shown an arrangement for providing ventilation in a structure formed from box-section components. To reduce heat loss, the box section 20 incorporates two insulating regions 21, preventing heat conduction through the horizontal webs 22 and 23 of the box section. To provide for passive ventilation in a conservatory or like structure, openings are formed in the vertical webs 24 and 25, and an insulating duct is installed to prevent communication between the outside air and the air within the box-section. Clearly, if such communication were allowed, heat loss would result and condensation problems would arise. In Figure 3, a duct 26 is shown, composed of two tubular elements 27 and 28 telescopically interengageable. The duct 26 is preferably of circular cross-section and is preferably moulded from resilient plastics material.To install the duct, coaxial circular openings are formed in the webs 24 and 25 of the ring beam, by drilling.

Inner element 27 is then inserted into the opening in web 24, and pushed home until barbs 29 engage the inside surface of web 24 to retain the element 27 with its flange 30 in close contact with the web 24. A resilient sealing ring or lip seal (not shown) may be provided.

The installation is completed by inserting element 28 through the opening in web 25, so that its end 33 slides over end 34 of element 27. A close sliding fit is envisaged, but a sealing ring, lip seal or a preapplied sealing compound may be used to ensure air tightness. element 28 is pushed in until its barbs 35 engage the inside surface of web 25, and its flange 36 sealingly engages the outside of the web 25.

Screens, louvres, or other insect barriers may be formed in the duct, as indicated at S and L in the Figure.

The duct may be of circular section, and a plurality of spaced circular ducts may be moulded integrally with a rectangular cover plate so as to provide a multi-duct ventilator of neat appearance. Rectangular or other cross-section may be used for duct 26, but this will involve forming correspondingly shaped aligned opening in webs 24 and 25.

Figures 4A to 4D show an alternative method of providing a ventilation passage 29 without destroying the insulating properties of a thermally-broken box beam 30 wherein, a ventilator may b formed by simply drilling a hole 31 in the beam and placing a quantity of uncured foaming insulation material 32 into the interior of the beam (Figure 4A), and allowing the material to cure (Figure 4B). The interior of the beam adjacent the opening now being filled with foam 33, a second drilling of the beam will produce a thermally broken beam with a ventilation passage 34 extending through the foam, isolated from the interior cavity of the beam. Cover plates 35 and 36 may then be fixed to the outer faces of the beam to provide a neat appearance and insect barrier.

If, prior to the assembly of the structure, the location of ventilating passages are known, then it is possible to pre-fill the box beams 30 at those locations with insulating foam 33, so that ventilation passages 34 may be formed on site by simply drilling through the beams at the required locations.

Claims (16)

1. A pitched roof structure comprising a ridge element, a beam extending substantially horizontally along the eave of the roof, and a plurality of inclined rafters extending from the ridge element to the inner face of the beam and supporting roofing panels or the like which contact the beam at the upper edge of its outer face, wherein the inner face of the beam provides a plurality of upwardly facing locating surfaces on which the rafters may rest, the vertical spacing of the locating surfaces being such that different angles of inclination of the rafters are accommodated by selecting the appropriate locating surface on which to rest the rafter end.

2. A pitched roof structure according to Claim 1, wherein the inner face of the beam is formed with a single locating surface adapted to receive a spacer in a plurality of different orientations, each orientation of the spacer providing an upwardly facing surface at a different distance from the upper edge of the beam.

3. A pitched roof structure according to Claim 2, wherein the beam is formed with a flange extending from its inner face, and a spacer of generally trapezoidal prism shape cooperates with the flange by means of a slot in the narrower of its parallel faces, the arrangement being such that one or other of the convergent faces of the spacer may face upwardly when the beam is horizontal, the angle between the vertical face of the beam and the uppermost inclined face of the spacer corresponding to the pitch angle of the roof, and the distance between the inclined face of the spacer and the upper edge of the beam corresponding to the vertical thickness of the rafter.

4. A roof structure according to Claim 1, wherein the rafter is a hollow tubular component and the said plurality of upwardly facing surfaces are provided by a plurality of inserts which can be fixed to the beam at predetermined vertical heights relative to the-beam, the inserts being receivable in the lower ends of the rafters to locate them relative to the beam.

5. A roof as claimed in Claim 4, wherein the inserts each include a downwardly facing surface to engage the upper face of the beam.

6. A roof according to any preceding Claim, wherein the beam is a hollow tubular metal section.

7. A roof according to any preceding Claim, wherein the beam comprises inner and outer metal channels joined at their free edges by an insulating material to provide a thermal break between the inner and outer faces of the beam.

8. A roof according to Claim 6 or Claim 7, wherein the beam is filled with an insulating material for at least part of its length.

9. A roof according to any preceding Claim, wherein ventilation openings are formed through the beam.

10. A roof according to Claim 9 as dependant on Claim 7, wherein the inner and outer faces of the beam are formed with aligned openings, and tubular elements are inserted through the openings to form a duct providing communication from the outer face to the inner face but denying access to the interior of the beam.

11. A roof according to Claim 10, wherein the tubular elements are telescopically engageable one with the other.

12. A method of providing a thermally insulated ventilation opening in a hollow metal section beam, comprising the steps of

1. forming an opening in a first face of the beam

2. injecting a quantity of insulating material into the beam through the opening, so as to fill the interior of the beam for a distance to each side of the opening.

3. forming a bore through the beam and the insulation material, so that no communication between the bore and the interior space in the beam is provided.

13. A roof structure substantially as described herein with reference to Figures 1, 1A, and 2 of the accompanying drawings.

14. A beam for a roof structure, substantially as described herein and shown in Figures 3 and 4A to D of the accompanying drawings.

15. A method of forming an insulated passage through a beam, substantially as described herein with reference to Figures 3 and 4A to D of the drawings.

16. Any novel feature disclosed herein, alone or in combination with any other feature herein disclosed, novel or otherwise.