IE913391A1

IE913391A1 - Roof fixing

Info

Publication number: IE913391A1
Application number: IE339191A
Authority: IE
Inventors: Richard George Vyse; Christopher Ponting; Terence Owen Andrew
Original assignee: British Steel Plc
Priority date: 1990-09-27
Filing date: 1991-09-26
Publication date: 1992-04-08
Also published as: GB2248253B; GB9120259D0; GB9021302D0; GB2248253A; IE65376B1

Abstract

A spacer 5 of elastomeric material is inserted between roof sheets 2 and the purlins 1 supporting the roof sheets particularly at the points where the roof is fixed to the purlins and provides drainage channels moulded into the spacer to allow liquid to drain down the inside of the roof minimising the collection of liquid in the gap between the purlin and roof. The spacer may, as shown, have pimples affording the drainage channels. In other forms, grooves may replace the pimples. The spacer may be adhesive-backed, and supplied in roll form.

Description

This invention relates to the fixing of roofs. Particularly in industrial building methods used to erect buildings for commerce, industry and agriculture the roofs may be made of large, substantially flat, sheets fixed to a horizontal parallel beams or purlins. The purlins are arranged in normal practice to support the roof sheets in an inclined manner so as to give the roof a pitch. The roof sheets are usually corrugated, in a variety of shapes such as trapezoidal or since soidal to create a more rigid sheet.

The roof sheets and purlins are commonly metal, although wooden purlins are used. Corrosion and rotting of the material can occur owing to the presence of water. The types of corrosion can be chemical, such as corrosion of the metal or the interaction of the chemicals used in the preservation of wood with the metal. Bimetallic effects with dissimilar metals in contact can also occur.

The presence of water can arise in several ways; by condensation on the underside of the roof sheet, or where the roof sheet has been punctured by a fixing, by leakage due to the inadequacy of overlaps between roof sheets or inadequate sealing.

The problems caused by this water are exacerbated because the water is often held by capillary attraction between the roof sheets, purlins and fixings, and also because water draining down the pitch of the roof on the underside will be stopped at a purlin.

It is therefore an object of this invention to reduce the problems of water induced corrosion in such roofs.

According to a first aspect of the present invention there is provided a spacer for use in a roof constructed by the fixing of roof sheets to purlins, in which the spacer is placed intermediate the roof sheet and purlin and provides drainage channels for liquid draining down the underside of the roof sheet.

OPR26/1488 lA The drainage channels may be formed by moulding the material of the spacer on the side placed adjacent the roof sheet. The spacer itself may be constructed of an elastomeric material which may be natural or synthetic rubber and the moulding may be in the form of pimples or ridges and furrows, the furrows forming of the drainage channels. A short spacer may be situated at a fixing point, or the spacer may extend along the length of the purlin. The spacer may be secured in place either by mechanical means, such as the roof sheet fixing or a lug designed to fit in an appropriate aperture in the purlin, or it may be attached by adhesive to the purlin. The adhesive may be in the form of pre-applied adhesive covered by a protective tape to be removed immediately before use.

According to a further aspect of the present invention, there is provided a roof constructed using such a spacer.

The invention will now be described with reference to the accompanying drawings of which:Figure 1 shows a roof in partial section constructed using a spacer; Figure 2 shows a pimpled spacer; Figure 3 shows a ridge and furrow spacer; and Figure 4 shows a sawtooth spacer.

With reference to Figure 1, there is shown a partial roof assembly.

Part of the roof sheet has been cut away to show the purlin (1) to which the roof sheet (2) has been attached.

The roof sheet is substantially flat, but it will be seen that corrugations (3) have been formed therein to increase its ridgity. The roof sheet is attached to the purlins by fixings (4) which may be of many types such as self tapping screws, nails, rivets, or bolts, depending on the precise nature of the roof sheet and purlin. A spacer (5) is applied between the top edge of the purlin and the roof sheet. In this case it will be seen that the purlin is metallic but a wide variety of materials and forms could be used, depending on the construction of the building and the need to provide ample support for the roof as well as easy fixing.

OPR26/1488 2 Turning now to Figure 2, there Is showed a spacer (5) such as was seen in place in an assembled roof in Figure 1. The spacer consists of a strip (6) made out of an elastomeric material, possibly a natural or a synthetic rubber. In the top surface of the spacer during manufacture are moulded, or otherwise formed, pimples (7). It will be appreciated that these pimples allow water to pass between them so that in position in a roof water may drain between the pimples and that the contact between the roof sheet and purlins is eliminated thereby reducing bimetallic effects. The pimples being the only support in contact with the roof sheet reduces the points at which water may collect by capillary attraction adjacent the sheet. The spacer may be approximately 5mm deep including the depth of the moulding, and as wide as is necessary for a particular purlin; this may commonly be from 56mm to 95mm and a width of 25mm for the spacer has been suggested. The length of the spacer can vary considerably. Small lengths of spacer may be in some circumstances inserted at the points of fixing so that the fixing means penetrates the spacer, or a spacer in the form of a long roll may be applied along the full length of the purlin before the roof sheet is applied. In the spacer shown in Figure 2 a self adhesive backing (8) is covered by a protective tape (9) which is removed immediately before the spacer is applied to the purlin. This self adhesive spacer in the form of a tape would be particularly suitable for use in roll form.

Turning now to Figure 3 there is shown a further possible form of spacer. The construction is very similar to the spacer shown in Figure 2 and will not therefore be described in detail. The major difference is the form of the moulding, which is in the form of ridges (10) which support the roof sheet surface and furrows (11) which provide drainage channels. It will be appreciated that for spacers of the type shown in Figure 3 the furrows must extend in the generally downward direction of the roof along which drainage naturally takes place.

In Figure 4, a further form of spacer is shown. Here a sawtooth (12, replaces the ridges and furrows shown in Figure 3. It will be appreciated that the variety of potential spacer forms is very large.

Claims

1. A spacer for use in a roof constructed by the fixing of roof sheets to purlins characterised in that the spacer is placed intermediate the roof sheet and purlin and provides drainage channels for liquid draining down the underside of the roof sheet.

2. A spacer as claimed in claim 1 in characterised in that the drainage channels are formed by moulding the material of the spacer on the side placed adjacent the roof sheet.

3. A spacer as claimed in claim 1 or claim 2 characterised in that it is of an elastomeric material.

4. A spacer as claimed in claim 3 characterised in that the elastomeric material is a rubber.

5. A spacer as claimed in claim 4 characterised in that the rubber is natural.

6. A spacer as claimed in claim 4 characterised in that the rubber is synthetic.

7. A spacer as claimed in any proceeding claims characterised in that the mouldings are in the form of pimples.

8. A spacer as claimed in claims 1 to 6 characterised in that the moulding is in the form of ridges and furrows, the furrows forming the drainage channels. OPR26/2829

9. A spacer as claimed in any proceeding claim characterised in that the spacer extends along the length of the purling and is fixed thereto by adhesive.

10. A spacer as claimed in claim 9 characterised in that the adhesive is pre-applied and covered by a protective tape to be removed immediately before use.

11. A roof characterised in that is constructed using a spacer as claimed in any preceding claim.

12. A spacer as claimed in any preceding claim, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.