GB2296021A - Spacer for over-roofing or over-cladding - Google Patents

Abstract

A spacer suitable for over-roofing and over-cladding applications is in the form of an elongate corrugated moulded element (5) of channel shaped cross section formed from a rigid thermoset or thermoplastics material. The base of the element is constituted by two opposed web portions which are shaped to conform to the profile of an under sheet (50) of an existing building whereas the crest is shaped to conform to the profile of new over sheets (45) to be fixed over the existing sheets. One or both of the web portions is/are provided with a series of indentations (20) located adjacent to the peaks of the sinusoidal crest to accommodate the fixings used to secure the under sheets to the original purlins or sheeting rails. A plurality of spacers may be fixed end to end in situ by means of male and female end portions. A spacer may be provided with a left handed or a right handed step formations (40') to enable the spacer to seat against a left or right sheet lap in the underlying sheet surface. When both of the webs (10) are provided with indentations the spacer may be universally laid right to left or left to right. <IMAGE>

Description

Spacer for Over-Roofing and Over-Cladding This invention relates to a spacer suitable for use In connection with overroofing and similar applications such as over-cladding. The term "overroofing" as used herein refers to the provision of a new weather tight roof which is installed over an old and usually defective roof of corrugated sheet material, especially corrugated asbestos cement sheeting. The over-roof may consist of lightweight sheeting of glass reinforced polyester material having a profile which substantially matches the profile of the original corrugated roofing sheet and which are fixed to the original purlins by means of suitable fasteners.The term "over-cladding" refers to the analogous provision of a new weather tight cladding which Is installed over an existing wall or other surface constructed of corrugated sheet and for the purposes of this specification the terms "over roofing" and "over-cladding" and related terminology are synonymous except where the context otherwise requires.

It is generally necessary, In the case of over-roofing asbestos cement sheet roofs to ensure that the new sheeting is supported at some distance above the original surface of the roof because such sheets are usually fixed by means of J bolts which have a projecting head or a nut on the external side of the roof. Since the original roof and fixings are retained, the new roofing sheets must be supported with sufficient clearance above the original roof in order to ensure that the original fixings do not contact the underside of the new sheet and to avoid any risk of the new sheet being damaged by the old fixings. In other cases, a cavity may be required between the original roof and the over-roof to provide space for non load bearing thermal insulation material, such as rockwool, to be installed.

A known form of spacer consists of a EPDM foam rubber strip which has been cut to conform to the common profile of the original and the over sheet and which is laid across the corrugations of the original roof sheeting above the purl ins at a position adjacent to the original fixings. The fixings for the over roof pass through the EPDM rubber spacers, securing the new roof to the original purl ins. The use of EPDM rubber strips as spacers Is not without attendant disadvantages. EPDM spacers are compressible under applied loads, particularly those caused by roofing workers walking on the roof, which may cause the over-sheet to be pressed against and be damaged by the original roof fixings, even if these have ail previously been cropped as short as possible.EPDM spacers are also not easy to locate, or to keep, in the correct position on the original roof surface prior to fixing especially during the laying of the over-sheet on top of the spacers when they may quite easily be disturbed without the disturbance being noticed. These disadvantages may be mitigated by the present invention.

In one aspect, the present Invention consists in a spacer suitable for use In over roofing or over-cladding comprising an elongate member of a rigid material having an upstanding crest portion at the top of the member and opposed outwardly projecting marginal edge portions at the base of the member the spacer being formed in the lengthways direction to substantially conform to the profile of corrugated sheets whereby, in use, the spacer may be inter-fittingly disposed between first and second corrugated sheet members, arranged transversely with respect to the corrugations of the two sheets, the marginal edge portions being formed so as to be substantially In contact with the profile of the first sheet member and the upstanding crest portion being formed so as to be substantially in contact with the profile of the second sheet member.

Preferably, the elongate member Is In the form of a channel section formed from a thin walled rigid material, such as glass reinforced polyester material or other thermoset or thermoplastics material.

In many applications, the spacers are required to be fitted In positions which are very closely adjacent to the lines of the original roof or wall fixings, in order that the fixings for the over-roofing or over-cladding sheets may be secured to the original, underlying purlins or sheeting rails It is desirable, and necessary in some cases, that the spacer is located above the original fixing means, which in the case of asbestos cement sheeting, are normally in the form of J bolts, as already mentioned, which have projecting portions on the external side of the roof, which are generally located at the position of the crests (although not usually at every crest) along the line of the underlying purl in.In order to be able to locate the spacer in a superimposed position above the original roof fixing means it is convenient to provide a series of indents or recesses in one of the outwardly projecting marginal edge of the spacer which indents or the like can house within them the projecting fixing means and so permitting the spacer to seat firmly in a superimposed position above the original fixings.In order to accommodate any possible occurring frequency of the original fixings, which will have to be housed, it is desirable that the indents or the like are provided along the marginal edge portion of the spacer adjacent to each one of the crests provided along it's length, since any redundancy of the number of indents so provided is of no real consequence An original corrugated roof or wall which is to be covered by the over-roofing sheets would normally have a plurality of sheets arranged with overlapping side edge portions across the width of the roof. In the case of corrugated asbestos cement roofing sheets, the overlapping edge corrugations are so formed that the crest of the upper one of the two corrugations in the overlap is at the same level as all of the other crests across the roof or wall.But the overlapping edge region, as just described, presents a step-shape, or surface discontinuity, which would prevent a spacer having a continuous surface from seating properly in the region of the underlying discontinuity. It must also be observed that the orientation of the discontinuity in the underlying surface depends upon whether, in the case of any particular surface, the original roofing sheets were laid from left to right, or from right to left when viewed from the eaves, for example.

It is accordingly preferred to provide a spacer with a step formation or discontinuity across the width of the spacer, the formation being of such dimensions as necessary to conform to the shape of the discontinuity or step like shape of the underlying sheet lap. Because the orientation of the discontinuity is handed, at least in the case of asbestos roofing sheets, it is advantageous to provide two forms of spacer to accommodate the handedness of a normal sheet overlap, each spacer being provided with a step formation in one of the corrugations which is shaped to conform to either a left-handed or a right handed lap in the underlying sheet.The step formation, of either hand, may be provided in a corrugation at or close to the edge of an over- sheet but it is advantageously provided in a corrugation which is one corrugation in-board of the edge corrugation, as will be further described herein.

At least one set of spacers, according to this Invention, for use with a particular roof or wall are preferably at least one corrugation longer than the width of either the original sheet or the over-roofing or over-cladding sheet (which over-sheets are normally arranged to be of the same width as the original sheets) in order that end portions of the spacers will project after being over laid with an over-roofing or over-cladding sheet as the case may be. This arrangement has advantages since when these longer spacers are used beneath the first sheet to be laid on one slope of a roof , which usually, like the other over-roofing sheets, extends continuously from the ridge to the eaves, the alignment and position of the spacers can be very readily be seen and adjusted if need be. Similar advantages arise from the use of these longer spacers in the case of over-cladding applications.

Moreover, the projecting end portions of the spacers also facilitates the end to end connection of the spacers across a roof or wall, the spacers all being advantageously provided with means for end to end interconnection which means are preferably in the form of male and female connecting parts As will be appreciated, these wider-than-normal starter spacers are also required to be handed and that a normal roof having two opposite pitches would advantageously utilise four different spacer configurations, namely both starter and normal length spacers of either hand.

Advantageously, both of the marginal edge portions of the spacer are provided with formations which are adapted to accomodate the heads of sheet fixings means. By providing such formations along both marginal edge portions, suitably at every corrugation, the spacer may be universally laid left to right and right to left so obviating the need to provide specifically left handed or right handed spacers, as the situation may require.

Preferably, the spacers are so formed that any condensation forming In the valleys or troughs of the underlying roof or wall may freely drain away. This may for example be achieved by the provision of flattened portions of the spacer which lie within the troughs of the original sheet to permit condensation to flow between the spacer and the under sheet.

The projecting marginal edge portions of the spacer and the crest are of sufficient width to provide adequate bearing surfaces for firmly and rigidly supporting the over-roof or over-cladding above the original roof and the height of the crest above the marginal edge portions may advantageously be the least distance required to clear the original roof fixings.Since the height and appearance of the original roof is not substantially changed by overroofing in accordance with this Invention, planning permission should not normally be required to be obtained prior to the over-roofing works being undertaken Spacers in accordance with this invention can be readily produced In the form of glass reinforced polyester or other thermoset or thermoplastic mouldings and made to conform to all types of existing roofing sheet profiles and to corresponding over-roofing sheets of matching profile One embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:: Figure 1 is a view from one side of a spacer Figure 2 is cross sectional drawing of the spacer along the line A-A shown in Figure 1 Figure 3 is a cross sectional drawing of the spacer along the line B-B shown In Figure 1 Figure 4 is a plan view of the spacer as shown In Figure 1 Figure 5 is a view from one side of a spacer of opposite hand from the spacer shown in Figure 1 Figures 6, 7, and 8 show views of the spacer shown in Figure 5 corresponding to the views shown by Figures 2, 3, and 4 respectively of the spacer shown in Figure 1 Figure 9 shows a cross section through an over-roof assembly viewed from the direction of the roof ridge as indicated by the arrow C in Figure 10, the assembly incorporating overlapping spacers of the kind shown in Figure 1 Figure 10 is a cross sectional drawing along the line A-A shown In figure 9 Figure 11 is a cross sectional drawing along the line B-B shown in Figure 9 Figure 12 is a view from one side of a spacer which Is similar to the spacer shown in Figure 1 except that It Is provided with an additional corrugation Figures 13, 14 and 15 show views of the spacer shown in Figure 12 corresponding to the views shown by Figures 2,3 and 4 respectively of the spacer shown In Figure 1.

Figure 16 is a view from one side of a spacer similar to the spacer illustrated in Figure 12 except that it is of the opposite hand Figures 17, 18 and 19 show views of the spacer shown in figure 16 corresponding to the views shown by Figures 13, 14 and 15 respectively of the spacer shown In Figure 12 Figures 20 and 23 are respectively side and plan views of an unhanded spacer: Figure 21 being a section along the line A-A and Figure 22 being a section along the line B-B shown In Figure 20.

Figures 24 and 27 are respectively side and plan views of an unhanded starter spacer; Figure 25 being a section along the line A-A and Figure 26 being a section along the line B-B shown in Figure 24.

Figure 28 illustrates various profiles of existing asbestos cement sheeting for roofing and cladding for which spacers according to this Invention may be formed.

Referring to the drawings, Figure 1 illustrates an elongate spacer, 5 of moulded GRP sheet material the length I-I being equal to the width of the original roofing sheet to be covered and having the same number and shape of corrugations as the original roofing sheet and which is hereinafter referred to as a "standard spacer" As will be seen from Figure 3 spacer 5 Is channel shaped in cross section having opposed marginal edge portions 10 formed at the base of the channel section and a crest 15 at the top of the section. As will be seen from Figure 2 one marginal edge portion 10 is indented at 20 to provide a recess for accommodating the original roof fixings as shall be further described below.The Indents 20 are provided In the edge portion 10 in the region of every crest of the spacer, as can be easily seen from Figures 1 and 4 Each trough 25 of the spacer is flattened so as to be raised clear of bottom of the trough of the original roofing sheet, as will be clearly seen by reference to Figures 9 and 11, when the spacer is in use, to allow any condensation to drain away without obstruction.

As may be seen from Figure 4 a plurality of spacers may be joined end -toend by means of male and female formations 35 and 30 respectively, the mechanical connection serving to preserve the accurate alignment of the spacers across the width of the roof. A step formation 40 Is provided In the bearing surface of the spacer 5, that Is, the surfaces of the two projecting marginal edge portions 10 which In use seat upon the upper surface of the original asbestos cement sheet roofing as may more easily seen In Figure 9 and which will be further described with reference to that Figure It may be noted that the step formation is located at one full corrugation inboard from the end of the spacer for a purpose to be further described.The standard spacer illustrated in Figures 1 to 4 is adapted by means of this step formation 40 to be laid from right to left across a roof as seen from the eaves that is the lowest level of the roof where a gutter is normally positioned.

The spacer which is illustrated with reference to figures 5 to 8 inclusive is in all respects the same as the spacer just described with reference to figures 1 to 4 Inclusive except of course that the position of the step formation identified by the numeral 40' in figure 5 Is laterally Inverted compared with the position of the step formation 40 In figure 1 The spacer of figure 5 Is accordingly adapted to be laid from left to right across the width of the roof, as viewed from the eaves, as before.

Referring to Figures 9, 10 and 11 an over roofing assembly is shown and which consists of an over layer of GRP roofing sheets 45 which are supported above the original roof of asbestos cement sheeting 50 by means of a spacer 5 as previously described. Since figure 9 is a view of the assembly from the roof ridge that is from the direction of arrow C In figure 10 it will be seen that the original asbestos cement sheets 50 were laid from right to left when viewed from the eaves and this requires the form of spacer shown in figure 1 to ensure that the spacer 5 seats properly on the original roof in the region of the overlap of the original asbestos cement sheets.The latter are fixed to purl in 55 by means of J bolts 60 having projecting nut and stud ends 65 projecting above the outer surface of the original roof, the projections 65 being housed within the indents 20 provided on the edge portion 10 of the spacer 5. Figure 10 best illustrates the location of the spacers In a superimposed position above the retained fixing means of the original sheet. This positioning, with the indents facing up the slope of the roof towards the ridge, allows the new fixing, in the form of self drilling, self tapping fixing bolts 70 to be attached to the original purlin 55.The over sheets 45 are retained by bolts 70 through seals 75 against the suitably broad crests 15 of the spacers 5 As may be seen from figures 9 and 11 the somewhat truncated form 25 of marginal edge portions 10 allows condensation to drain down the original roof towards the eaves gutter, not shown.

It will be observed from figure 9 that whereas the lapping of the over-roofing coincides with the lapping of the original roofing, the joining of the spacers occurs at a position one corrugation removed from the position of the roof sheet laps. It is advantageous to provide a starter set of spacers which are characterised by being longer than the width of the roofing or over-roofing sheets and examples of such starter spacers are illustrated In figures 12 to 15 inclusive and in 16 to 19 Inclusive. These spacers are the same as standard spacer counterparts already described except for the fact that they are longer, In this case by one corrugation compared with the standard spacer.The first over-roofing sheet Is laid either from the left hand or right hand side of the roof using spacers of the appropriate hand using the starter spacers which are one corrugation longer than the width of the roofing sheets. The end portions of the starter spacers accordingly project from underneath the edge of the first over laid sheet. This facilitates the edge-toedge connection with subsequent standard spacers and also facilitates the alignment and positioning of the spacers with the required accuracy above the purlin to which they are fixed by the bolts 70 for the support of the overroof.

Referring to Figures 20 and 23, the opposed marginal edge portions 10 and 1 0a of spacer 5 are each provided with a series of formations in the shape of indentations 20 and 20a, respectively , located adjacent to each of the crests of the spacer.5. The form of the indentations 20 or 20a may be more clearly seen with reference to Figure 21. The spacer 5 may be reversed so that either set of indentations may be employed to cover a series of under sheet fixings the choice depending on whether the step formation 40 is required for left handed or right handed laying.to the under sheet. An unhanded spacer as described is particularly advantageous since only one form is suitable for both left and right handed laying.

Figures 24 to 27 illustrate an un-handed starter spacer which Is similar in all respects to the spacer described with reference to Figures 20 to 23 except that it is a corrugation longer for purposes previously described.

Claims (11)

Claims

1. A spacer suitable for use in over roofing or over cladding applications comprising an elongate member of rigid material having an upstanding crest portions and opposed outwardly projecting marginal edge portions provided at the base of the member, the spacer being formed in the lengthways direction to substantially conform to the profile of corrugated sheets whereby In use the spacer may be inter-fittingly disposed between first and second corrugated sheet members when arranged transversely with respect to the corrugations of the sheets, the marginal edge portions of the spacer being formed for contact with the profile one of the sheet members the crest portions being formed for contact with the profile of the other sheet member

2 A spacer as claimed In Claim 1 In which at least one of the marginal edge portions is provided with formations which are adapted to accommodate the heads of sheet fixing means when, in use, the spacer is arranged along a line of such fixings securing an under sheet.

3. A spacer as claimed In Claim 2 In which the formations are indents provided in the marginal edge adjacent to each of the crest portions

4. A spacer as claimed in any preceding claim which Is provided with a step formation across the width of the spacer. the step formation being dimensioned to substantially conform to the step like shape of an underlying sheet lap over which the spacer Is secured In use

5. A spacer as claimed In Claim 4 In which the step formation Is arranged to accommodate either a left handed or a right handed lap of an underlying sheet

6. A spacer as claimed In Claim 4 or 5 in which the step formation Is located inboard of one distal end of the spacer by a distance of one corrugation

7.A spacer as claimed in any preceding Claim which Is at least one corrugation longer than the width of either of the corrugated sheets which In use are disposed on either side of the spacer.

8. A spacer as claimed In any preceding Claim In which the distal ends thereof are provided with complimentary inter engaging formations whereby In use a plurality of spacers may be inter engaged in end to end relation.

9. A spacer as claimed in any preceding Claim which Is channel shaped In cross section and formed from a rigid material

10. A spacer as claimed In Claim 9 In the form of moulding of glass reinforced polyester or other thermoset or thermoplastics material.

11. A spacer as claimed in any preceding claim which Is adapted to allow for drainage whereby in use condensation forming between under sheeting and over sheeting may drain away 12 Cladding for a building comprising an under cladding of corrugated sheet material and an over cladding of corrugated sheet material the over cladding sheets being mounted on a plurality of spacers as claimed in any preceding claim the spacers being arrange on and affixed te the under cladding of sheet material 13. A spacer substantially as described with reference to any of the accompanying drawings