GB2241259A - Resisting wind-lift in flat roofing - Google Patents

Abstract

Loose-laid insulation slabs 19 on a flat roof 18 are interconnected at an edge of the roof by a pair of rails 22 to form a unified edge structure to resist wind-lift of the slabs. Each rail connects a respective row of slabs 19. Selected slabs 24 bridge between the rails 22. The slabs interengage by tongue and groove or rabbeted joints. <IMAGE>

Description

FLAT ROOFING This invention relates to flat roofing.

Referring to Figures 1 and 2 which illustrate the prior art, it is not unusual in the case of a roof structure 10 which has a surrounding parapet 11 to overlie the roof structure 10 with loose but interconnected insulating panels 12. Provided the panels 12 are sufficiently heavy they can be loose laid without being connected to the roof structure 10 (very important as the roof structure does not need to be pierced or interfered with in any way which may alter its waterproof nature.) As best seen in Figs 5a and 5b the panels 12 will normally comprise an insulating layer 13 united with a layer 14 which can be of concrete or the like.

If such roof insulating panels 12 can be laid with their outer edges close to the edge of a tall parapet, the edge panels are usually sufficiently shrouded to resist wind uplift forces to certain levels. However, if there is a gutter (such as 15) there is a gap adjacent the edge of the panel 12 and this can allow wind lift to occur. In circumstances where the weight of the panel does not give sufficent resistance to wind uplift, (for example in particularly windy areas) it may be necessary to add additional hold down means such as ballast 16. Such loose ballast 16 may be in the form of paving slabs which although they can be easily laid regularly, are often moved by users or can suffer from creep due to regular loose movement during wind. If the ballast moves, it may move to a position where it is ineffective to prevent panel uplift.

It is an object of the present invention to provide an improved system of restraining loose laid insulation or like panels on a roof against wind uplift, and to provide a construction which provides a significant increase in the wind uplift figure enabling ballast to be dispensed with in a large range of areas.

The invention provides a roof construction which includes a basic roof structure and overlying loose laid insulating panels, the or each edge of the roof susceptible to wind uplift being provided with means for connecting together selected ones of said roof panels in an area adjacent said edge, said means including a pair of frame members and at least some of said panels bridging said frame members at regular intervals and being secured thereto.

The frame members can be secured to all the panels over which they pass. The frame members can be angle members laid parallel to each other. Desirably an outer one of the members overlies an outer line of the panels and desirably an inner one of the members overlies a penultimate line of the panels, certain panels in the array bridging between the two members to unite.

The invention will be described further, by way of example with reference to the accompanying drawings wherein: Figs. 1 and 2 are fragmentary side elevations of portions of roofs showing prior methods of increasing the wind resistance of loose laid panels; Fig. 3 is a view similar to Figs 1 and 2, but illustrating a roof construction of the invention Fig. 4 is a plan view illustrating a comparable roof construction similar to but not identical to that shown in Fig. 3; and Figs. 5a and 5b illustrate two possible connections between panels of the various reconstructions, in accordance with prior art.

Figures 1, 2 and 5 have already been described in a little detail in the introduction and will not be described further in great detail. However, it will be seen that the invention is particularly concerned with the application to an existing roof structure of a loose laid layer of insulating panels which are interconnected but separate, for example in the manners illustrated in Figs. 5a and 5b.

Although independant and loose, upon lifting the panels do interact with surrounding panels so that a single panel cannot be lifted from the roof without interfering with others.

In a preferred roof construction 17 of the invention (Figs. 3 and 4) there is a basic roof structure 18 over which have been laid a plurality of panels 19 comparable to panels 12, having a herringbone pattern as will be seen in Figure 4. The structure 18 is surrounded by a parapet 20. In Figure 3 there is shown a gutter 21 which is omitted from Figure 4. This is the only difference between the two roofs shown in the two drawings. Instead of the ballast 16 which is shown in Figs. 1 and 2, resistance to uplifting in the edge region 21 of the roof adjacent a vulnerable edge (a vulnerable edge can be an edge of roof adjacent a shallow parapet or can be at an edge of roof which is adjacent a gutter 21 and therefore in which the panels 19 cannot be abut right up to the parapet, or be covered by a separate hold down means.In the region 21 an area of panels 19 is united by a frame in the form of longitudinally extending parallel members 22. The members 22 are secured to the panels 19 by fasteners indicated at 23. As illustrated schematically in Fig. 3 the fasteners 23 can be cavity fixings which pass through the hard concrete layer 14 and expand within the insulating foam 13.

It will be seen that the outer member 22 is secured to the edge row of panels and the inner member 22 is secured to the penultimate row. However, it will also be seen in that at regular intervals panels 24 bridge the two members and unite them in the manner of a railway line. This connection, together with the Figure 5 interconnection between all the panels 19 results in the generation of a united edge portion of the roof which gives a much increased resistance to uplift compared with existing ballast methods but without the loose ballast 16. The construction is quite simple to effect and the members 22 can be carried up on the roof very easily as they are relatively light being made from thin metal. They can easily be replaced if and when they fail through rust and they can be easily inspected.They are not easily moved once they have been installed and they cannot be lifted from the roof without significant work.

The wind uplift load figures obtained using the method of the invention compare favourably with those previously achieved and allow such panel insulation to be used in a much larger area than was previously possible.

The invention is not limited to the details of the foregoing and variations can be made thereto. For example, the frame need not comprise two parallel members, but a comparable array of members can be used, provided there is bridging by selected of the panels 19 to form a unified edge therewith. The frame members need not be of angle section steel, they can be of any convenient material which is sufficently rigid light and cheap enough to do the job.

Plastics materials are not ruled out, but their rigidity for weight and price would probably tend to make them economically unattractive.

Other metal sections such as T-section, channel sections or tubular sections could be used.

Many other variations are possible within the scope of the invention.

Claims (10)

1. v

   CLAIMS 1. A roof construction which includes a base and overlying loose-laid insulating panels, the or each edge of the roof susceptible to wind uplift bing provided with means for connecting together selected ones of said roof panels in an area adjacent said edge, said means including a pair of frame members.
2. 2. A roof according to claim 1, wherein the frame members are secured to all the panels over which they pass.
3. 3. A roof as claimed in claim 1 or 2 wherein the frame members are angle members.
4. 4. A roof as claimed in any of claims 1 to 3 wherein the frame members are laid parallel to each other.
5. 5. A roof as claimed in any of claims 1 to 4 wherein an outer one of the members overlies an outer line of the panels and an inner one of the members overlies a penultimate line of the panels.
6. 6. A roof as claimed in claim 5 wherein certain panels in the array bridge the two members to unite them.
7. 7. A roof as claimed in any preceding claim wherein the or each edge of the roof which is provided with said means is a vulnerable roof as hereinbefore defined.
8. 8. A roof as claimed in claim 7 wherein said vulnerability is conferred by a low parapet.
9. 9. A roof as claimed in claim 7 wherein a gutter is disposed betwen a parapet and an edge of the loose laid insulating panels.
10. 10. A roof construction substantially as hereinbefore described with reference to and as illustrated in Figs. 3 and 4 of the accompanying drawings.