GB2117026A - Roof underlining and method of erection - Google Patents

Abstract

The underlining formed of panels 12 passes under and is secured to, roof support members, e.g. purlins 2, having upward-extending lips 11 at their lower parts. Working from the panels 12 are pulled up against the bottom flanges 9 of the purlins 2 and are secured by profile strips 13, tension bolts 14, hooks 16 which hook over lips 11, and nuts 17. Erection is simplified and staging is not required. An outer roof cladding 4 is shown. <IMAGE>

Description

SPECIFICATION Erecting a roof underlining Background of the Invention This invention relates to erecting a roof underlining which passes under roof support members having upwardly-extending lips on their lower parts. Usually such roof support members are formed from cold-rolled steel, and have lower flanges which extend generally parallel to the underlining or to the roof itself, said lips being on the outer edges of the flanges and usually extending normally to the plane of the underlining.

The roof support members may be purlins on a roof having a slope or fall, i.e. members which extend parallel to the apex or ridge of the roof; however, the roof support members could be other main or subsidiary roof support members.

In one method of erecting a roof underlining which passes under the roof support members, lining panels forming the roof underlining are screwed up from underneath into the bottom flanges of purlins. This is relatively difficult to do, and staging is required for the erectors.

The Invention The present invention provides methods as set forth in Claims 1 and 10, and roof constructions as set forth in Claims 11 and 13. The remaining Claims set forth preferred features of the invention.

Using the invention, the lining panels are fixed from the top, which saves time and money and avoids the requirement for staging or for reaching under whilst fixing. The bottom flange of the roof support member, if present, is not weakened by having holes formed therein.

Embodiments of the Invention The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical section along the line I-I of Figure 2, showing part of a roof construction; Figure 2 is a plan of part of the roof construction, on a smaller scale; Figure 3 is a section along the line Ill-Ill of Figure 2: and Figure 4 is a vertical section corresponding to part of Figure 1, but on a smaller scale, showing two modifications which can be made to the roof construction of Figure 1.

The roof construction is fundamentally of a conventional type, having rafters 1 which run up the roof slope towards the roof apex (not shown), purl ins 2 secured to the rafters by cleats 3 (Figures 2 and 3), a corrugated asbestos cement or metal outer cladding 4 (not shown in Figure 2) secured to the purlins 2 with the interposition of a compressed mineral fibre or similar thermal break 5, and a thermal insulation quilt 6. As shown clearly in Figure 1, each purlin is of a conventional type having a web 7, top and bottom flanges 8, 9 (i.e. flanges on the top and bottom parts of the purlin 2) and top and bottom lips 10, 11 on the outer edges of the respectice flanges 8, 9, the lips projecting respectively downwards and upwards normal to the plane of the roof and of the underlining. Other shapes of purlin may be used, for instance the Zeta purlins 2 shown in Figure 4.

Z-purlins and Zeta purlins are stronger if the bottom flanges 9 project down the slope, as shown in Figures 1 and 4.

There is an underlining which passes beneath the purlins 2, the underling being formed by corrugated sheet metal lining panels 12 of a type already known, normally having a plastics-coated undersurface and providing drainage for any condensation in the roof space. The lining panels 12 overlap at their ends and at their edges, as is indicated in Figure 2, and are suitably notched to pass around any cleats 3.

In accordance with the invention, the lining panels 12 are secured in position by lining panel securing means which comprise profiled strips 1 3 which extend beneath the lining panels 12 and parallel to the respective purlins 2, extended tension members in the form of bolts 1 4 having screw-threaded shanks 15, hook members in the form of "Oakley" clips through which the bolts 14 pass and which hook over the bottom lips 1 and tension applying means in the form of nuts 17 associated with the "Oakley" clips 1 6 for applying upwards tension to the bolts 14 and causing the "Oakley" clips 16 to pull down on the bottom lips 11, thereby pulling the strips 1 3 and the lining panels 12 up against the bottoms of the purlins 2 and forming a roof underlining.Other arrangements are possible for the hook members and the tension applying means. Furthermore, it would be possible to omit the strips 13, but the strips 13 enable thingauge lining panels 12 to be used without the panels 1 2 bowing down between the fixings.

Furthermore, it is convenient to have the lining panels 1 2 manufactured with relatively large tolerances (e.g. 6 mm on the length), giving a rather untidy appearance at the overlaps if the strips 13 are absent. The lining panels 12 are shown connected to each other by pop rivets 18, which forms a safety structure should anyone break through the outer cladding 4, this is particularly relevant if the outer cladding 4 is of asbestos cement.

The strips 1 3 are formed of sheet metal which can be plastics-coated on its underside, and as seen in vertical section normal to the purlins 2 (Figure 1), each strip 13 is non-rectilinear, having three flat upper surfaces for bearing up against the underside of the lining panels 12, separated by grooves 1 9 whose sides are slanted at a substantial angle both to the plane of the underlining and to the normal thereto, e.g. at 300 to 60 to the normal, 450 being shown.

The strips 1 3 have the advantage that the top side is not visible and thus need not be painted or plastics coated. However, as an alternative, a simple up-turned channel 20 (flanges extending downwards) could be used, as indicated in Figure 4.

Figure 1 also shows how the strips 1 3 (or channels 20) can be used to support services 21.

During or after erection, a metal strap 22 (e.g.

steel 10 mm wide) is clipped over the strip 13, the strap 22 having pressed-in seatings 23 and clips 24 which are accommodated in crests of the corrugations in the lining panels 12. The strap 22 holds the services 21 loosely in position, and the services 21 are then covered by a cover strip or channel 24 having upper lips which snap into the seatings 23 - the channel 24 may be made for example of steel or plastic.

Erection Procedure The roof support construction, comprising the rafters 1 and purlins 2, is erected. Starting from the eaves (lower edge of the roof), the lining panels 12 are laid in position. The "Oakley" clips 1 6 are hooked over the bottom lips 11 of the purlins 2 to one side of their final location, with the support strips 13 hanging below the purlins 2 with a gap therebetween for the insertion of the lining panels 12. The strips 13 and associated parts are then slid sideways along the bottom lips 11 into their final locations. Once the lining panels 12 nearest the eaves have been placed in position, the following procedure is adopted. The upper end portions of the lining panels rest on respective support strips 13.The edge portion of a piece of material (not shown) of similar profile to a lining panel 12 (normally a piece of scrap lining panel) is notched to allow its upper end portion to pass over the strip 13 without fouling the bolts 14, and is then pushed over the upper end portion of the lower lining panel 12 and under the bottom flange 9 of the purlin 2. The lower end portion of the next lining panel 12 is placed down on the projecting upper end portion of the scrap piece of material.

The lower end portion of the next lining panel 12 is slid under the bottom flange 9 and above the scrap piece of material, above the strip 1 3 and over the upper end portion of the first lining panel 12. The slanted sides of the grooves 1 9 in the strip 13 help prevent the end of the next lining panel 12 jamming in the groove even if it enters the groove.

If difficulties are encountered because the strips 13 cant over or twist along their length, a piece or pieces of wood, e.g. battens 20 mm thick, can be pushed through between the strips 1 3 and the bottom flanges 9 to keep the strips 1 3 more or less in their correct positions. The next lining panel 12 will have been notched as indicated at 24 in Figure 2 so that its lower end can be slid past the bolts 14. As the bolts 1 4 can be widely spaced (for instance at 900 mm), not much notching is required. The upper end of the next lining panel 12 is then rested on the next strip 1 3 up the roof and the piece of scrap material is withdrawn. The lower strip 13 is then pulled upwards against the overlapping end portions of the lining panels 12 to pull them in turn up against the bottom flange 9 of the purlin 2, by tightening the nuts 1 7. All these operations can be performed by erectors using crawling boards resting on the purlins 2.

It would be seen that the underling has a neat appearance, with the strips 1 3 concealing the overlapping ends of the lining panels 12. The underlining formed by the lining panels 12 can be erected working from above the lining panels 12, and the bottom flanges 9 and bottom lips 11 of the purlins 2 are not weakened in any way for instance by passing screws up through them.

Claims (12)

1. A method of erecting a roof underlining which passes under roof support members having upwardly-extending lips on their lower parts, the method comprising: hooking lining panel securing means over said lips, and, working from above the lining panels, using said securing means to pull lining panels up directly or indirectly against the bottoms of the roof support members and thereby secure the lining panels in position and form a roof underlining.

2. The method of Claim 1, wherein the lining panel securing means comprise the extended tension members, hook members through which the tension members pass and which hook over said lips, and tension applying means associated with said hook members for applying upwards tension to the tension members and causing the hook members to pull down on said lips.

3. The method of Claim 2, wherein the hook members are "Oakley" clips, the tension members have screw-threaded shanks, and the tension applying means are nuts above the hook members.

4. The method of any one of the preceding Claims, wherein the lining panel securing means comprise strips which extend beneath the lining panels and parallel to said roof support members.

5. The method of Claim 4, wherein the strips conceal edges of the lining panels, as seen from below.

6. The method of Claim 4 or 5, wherein the strips are formed of sheet metal which, as seen in vertical section normal to said roof support members, is non-rectilinear, having a t least two flat upper surfaces for bearing up against the under side of the lining panels, said upper surfaces being separated by a groove whose sides are slanted.

7. The method of any one of Claims 4 to 6.

wherein the lining panel securing means are hooked over said lips prior to placing the lining panels in position, and support said strips below said roof support members with a gap therebetween for the insertion of the lining panels.

8. The method of Claim 7, wherein the lining panel securing means are hooked over said lips to one side of their final location and are slid sideways along said lips into their final location.

9. The method of any one of Claims 4 to 8, wherein: a lining panel is placed in position with opposite end portions resting on respective, parallel, spaced said strips; the edge portion of a piece of material of similar profile to a lining panel but notched to allow its end portion to pass over the strip without fouling the lining panel securing means is pushed over one end portion of the first-mentioned lining panel and under the respective said roof support member; the respective end portion of the next lining panel is placed down on the projecting end portion of said piece of material; the respective end portion of the next lining panel is slid under said roof support member and above the strip and above the end portion of the first-mentioned lining panel; the opposite end portion of the next lining panel is rested on the next strip and said piece of material is withdrawn; and the first-mentioned strip is pulled upwards against the overlapping lining panel edge portions to pull them in turn up against the bottom of said roof support member.

10. A method of erecting a roof underlining, substantially as herein described with reference to, and as shown in, Figures 1 to 3 or Figures 1 to 4 of the accompanying drawings.

11. A roof construction comprising: roof support members having upwardlyextending lips on their lower parts; an underlining which passes beneath the roof support members, the underlining being formed by lining panels; and lining panels securing means which hook over said lips and pull the lining panels up directly or indirectly against the bottoms of the roof support members and thereby secure the lining panels in position, the securing means being of the type which are tensioned from above to pull the lining panels up against the bottoms of the roof support members.

12. The construction of Claim 11 and erected according to the method of any one of Claims 2 to 9.

1 3. A roof construction, substantially as herein described with reference to, and as shown in, any one of Figures 1 to 3 or Figures 1 to 4 of the accompanying drawings.