GB2169016A

GB2169016A - A method of strengthening roofs

Info

Publication number: GB2169016A
Application number: GB08531022A
Authority: GB
Inventors: James Robert Pelmore
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-12-19
Filing date: 1985-12-17
Publication date: 1986-07-02
Also published as: GB8531022D0; GB8432056D0

Abstract

A method of strengthening a roof of the type in which an assembly of slates or tiles 10 is hung on a series of spaced battens 11 comprises the step of positioning an elongate rectangular block 15 in the angle between an individual slate 10 and a side face of a batten 11. The block 15 is made from foamed polyurethane which has a high tensile strength but which is somewhat flammable and has its upper and front faces adhesively bonded to the slate and batten respectively. The exposed lower and rear faces of the block are covered with a layer 16 of non-combustible material which obstructs the access of air to the block 15, which air in the event of a fire would enable the polyurethane blocks to burn. <IMAGE>

Description

SPECIFICATION A method of strengthening roofs This invention relates to a method of strengthening roofs formed of slates or tiles hung on a series of spaced battens.

In the present Applicant's British Patent Specification No. 1,337,653 a method of strengthening roofs was described in which a strip or block of a foamed plastics material is positioned in the angle between a roof batten and a slate and is adhesively secured to both the slate and the batten. The foamed plastics material prevents the slate from sliding longitudinally down the roof in the event of failure of the securing nail and prevents the slate from lifting as the result of wind suction.

Foamed polyurethane was found to have excellent tensile strength characteristics combined with a satisfactory degree of flexibility and was thus used extensively as the foamed plastics material, despite its somewhat flammable nature.

According to the present invention there is provided a method of strengthening a roof of the kind in which an assembly of slates or tiles is hung on a series of spaced battens comprising the steps of positioning in an angle between an individual slate or tile and side face of a batten a block formed from a non-metallic material having at least a portion of only its exposed surfaces covered by a layer of non-combustible or substantially noncombustible material and adhesively bonding the block to both the slate or tile and the batten.

In a preferred embodiment said non-metallic material is a foamed plastics material.

Preferably said non-combustible material is metal foil or foamed phenolformaldehyde resin or foamed polyisocyanurate.

In preferred methods the block is rectangular in cross-section and has its upper and front faces bonded to the slate or tile and batten respectively and has its lower face covered by said layer of non-combustible or sub stantialiy non-combustible material or the block has a cross-section in the form of a right angled triangle and has its perpendicular faces positioned in said angle and has its largest, exposed face covered by the layer of non-combustible or substantially non-combustible material.

The invention will now be described in more detail with reference to the accompanying drawings in which: Figure 1 is a sectional view of a slate roof illustrating a first embodiment of the invention; Figure 2 is a sectional view of a slate roof illustrating a second embodiment of the invention, and Figure 3 is a sectional view of a slate roof illustrating a third embodiment of the invention.

In all three figures, slates 10 are secured by means of nails 12 to spaced battens 11 to constitute a roof. The roof is strengthened by adhesively securing in the angle between individual slates and battens elongate blocks 13; 15; 17 which in the three embodiments described are formed from foamed polyurethane.

In Fig. 1 each block 13 is rectangular in cross-section and has secured to its underside, that is its surface opposite that which is secured to the slate, a non-combustible layer 14 made from say metal foil. The block 13 is made from foamed polyurethane which has a suitably high tensile strength to resist lifting of the slates caused by the wind but which is somewhat flammable. The layer 14 of metal foil therefore obstructs the access of atmospheric oxygen to the polyurethane block.

Such a passage of oxygen would, in the event of a fire, aid the combustion of the polyurethane block 13 thus lead to possible widespread damage of the roof.

In Fig. 2 each block 15 is again rectangular in cross-section but has secured to its rear surface that is its surface opposite that which is secured to the batten, and its underside a non-combustible layer 16. Each layer 16 is made from a fire-resistant or self-extinguishing foamed plastics material such as foamed phenolformaldehyde resin or foamed polyisocyanurate which merely char when exposed to fire and form a surface layer of carbon to prevent oxygen from reaching the flammable polyurethane. The embodiment of Fig. 2 has an advantage over that of Fig. 1 in that blocks 15 have non-combustible layers 16 on both of their exposed major surfaces and are thus more effective in the event of a fire to protect the polyurethane.

In Fig. 3 each block 17 is, in cross-section, a right angled triangle and has its perpendicular faces positioned in and adhesively secured in the angle between its associated slate 10 and batten 11. The other major face, corresponding to the hypotenuse of the right angled triangle, has a non-combustible layer made of metal foil, foamed phenolformaldehyde resin or foamed polyisocyanurate bonded thereto to effect a barrier between the foamed polyurethane of the block 17 and the atmosphere. The embodiment of Fig. 3 uses less foamed polyurethane than that in Fig. 2 and also has the advantage that only one surface of the block 17 is covered by a noncombustible layer to effect a barrier compared to two surfaces in Fig. 2.

Additional security can be effected by also covering the end faces (not shown) of each block 13; 15; 17 thus in the embodiments of Figs. 2 and 3 totally sealing the blocks 15; 17 from atmospheric oxygen.

The blocks may be made from other foamed plastics or other non-metallic materials such as wood, wood composites, solid plastics, rubber or synthetic rubber having suitably high tensile strength.

The materials used to form the layers 14; 16; 18 are merely examples of substances suitable to obstruct the ingress of oxygen to the polyurethane. It will also be appreciated that the non-combustible layers may be attached to the blocks either on site or in the production stage.

Claims

1. A method of strengthening a roof of the kind in which an assembly of slates or tiles is hung on a series of spaced battens comprising the steps of positioning in an angle between an individual slate or tile and a side face of a batten a block formed from a nonmetallic material having at least a portion of only its exposed surfaces covered by a layer of non-combustible or substantially non-combustible material and adhesively bonding the block to both the slate or tile and the batten.

2. A method as claimed in claim 1, wherein said non-metallic material is a foamed plastics material.

3. A method as claimed in claim 1 or claim 2, wherein said non-combustible material is metal foil.

4. A method as claimed in claim 1 or claim 2, wherein said non-combustible material is foamed phenloformaldehyde resin.

5. A method as claimed in claim 1 or claim 2, wherein said non-combustible material is foamed polyisocyanurate.

6. A method as claimed in any one of claims 1 to 5, wherein the block is rectangular in cross-section and has its upper and front faces bonded to the slate or tile and batten respectively and has its lower face covered by said layer of non-combustible or substantially non-combustible material.

7. A method as claimed in claim 6, wherein the rear face of the block is also covered by the layer of non-combustible or substantially non-combustible material.

8. A method as claimed in any of claims 1 to 5, wherein the block has a cross-section in the form of a right angled triangle and has its perpendicular faces positioned in said angle and has its largest, exposed face covered by the layer of non-combustible or substantially non-combustible material.

9. A method as claimed in any one of claims 1 to 8, wherein the end faces of said block are covered by a layer of non-combustible or substantially non-combustible material.

10. A method substantially as hereinbefore described with reference to and as illustrated in the drawings.

11. A roof strengthened by a method as claimed in any of the preceding claims.