GB2375360A

GB2375360A - An expansion joint for guttering

Info

Publication number: GB2375360A
Application number: GB0208726A
Authority: GB
Inventors: Brian Mclntyre; Robert Rae
Original assignee: CGL COMETEC Ltd
Current assignee: CGL COMETEC Ltd
Priority date: 2001-04-18
Filing date: 2002-04-17
Publication date: 2002-11-13
Anticipated expiration: 2022-04-17
Also published as: GB2375360B; IE20020283A1; GB0208726D0; GB0109516D0

Abstract

The joint comprises first and second gutters 3, 5 which abut one another and are secured to one another by a structural sealant adhesive 8. The sealant adhesive 8 is a modified silicon sealant that is sufficiently strong so as to provide a watertight expansion joint without the need for mechanical fixings. The joint itself may be a joggle joint (figs.1-4) or else may be a butt strap arrangement (fig. 5).

Description

GUTTER EXPANSION JOINT 1 The present invention relates to an expansion joint 2 and in particular to an expansion joint for 3 guttering that remains watertight under thermal or 4 mechanical expansion of the joint.

5 6 Gutter expansion joints are used so that guttering 7 remains watertight when subject to strain. A 8 traditional technique for joining gutter sections 9 relies on the use of a joggle joint or butt strap 10 with a sealant applied between the sections. Once 11 the sealant is applied, the sections are fixed by 12 bolts or similar mechanical fixing means. The 13 employment of such fixing means has the obvious 14 disadvantage that holes are required to be punched 15 through the section pieces, and the holes themselves 16 can become the source of leaks and, in metal 17 sections, a source of metal fatigue or corrosion.

18

1 A more recent alternative to the above technique 2 involves the use of butt straps. Butt straps are 3 attached across an expansion gap between any two 4 sections. Placed over the top of the butt strap is 5 a membrane that can then be solvent or heat welded 6 in place to provide the water tight expandable 7 joint. Although providing a significant improvement 8 in terms of reliability over the previous methods, 9 the use of butt straps is still time consuming, 10 relying on solvent or heat welding to be carried 11 out. Accordingly the formation of such systems 12 tends to be carried out at the factory before being 13 transported to the required location.

14 15 It is an aim of the present invention to obviate or 16 mitigate one or more of the problems described 17 above.

18 19 According to a first aspect of the present 20 invention, there is provided a gutter expansion 21 joint comprising first and second gutter sections, 22 the first gutter section having an abutting portion 23 which abuts a corresponding abutting portion on the 24 second gutter section, wherein at least one of the 25 abutting portions has an adhesive sealant applied 26 thereto such that the first and second gutter 27 sections are fixed together by said adhesive 28 sealant.

29 30 In a preferred embodiment, the abutting portion of 31 the first gutter section comprises a joggle portion, 32 and the abutting portion of the second gutter

1 section comprises a projecting shelf, wherein the 2 adhesive sealant is applied to the joggle portion 3 such that the shelf is adhered thereto.

4 5 Preferably, the joggle portion has barrier means for 6 retaining the adhesive sealant thereon. Preferably, 7 the barrier means comprises a stopper fixed to the 8 joggle portion. Alternatively, the barrier means 9 comprises one or more shaped troughs.

10 11 In a second preferred embodiment, both abutting 12 portions have adhesive sealant applied thereto, the 13 joint further comprising a butt strap positioned 14 over the joint and fixed to the abutting portions of 15 the first and second gutter sections by the adhesive 16 sealant.

17 18 Preferably, one of the first and second gutter 19 sections has a projecting flange extending at least 20 partially around the outer perimeter of the abutting 21 portion of the gutter section, the outer surface of 22 the other gutter section adjacent the abutting 23 portion being positioned on said flange.

24 25 The adhesive sealant is a modified silicon 26 structural sealant having a breaking strength 27 greater than 1N/mm2 and preferably greater than 28 2N/mm2.

29 30 Preferably, the adhesive sealant has a maximum 31 allowed distortion of 25%. Preferably, the 32 adhesive sealant also has a modulus of elasticity in

1 the range 0.5-1. 5N/mm2 and most preferably in the 2 range 0.75-1. 5N/mm2.

3 4 According to a second aspect of the present 5 invention, there is provided a method of forming a 6 gutter expansion joint from first and second gutter 7 sections, the first gutter section having an 8 abutting portion adapted to abut a corresponding 9 abutting portion on the second gutter section, the 10 method comprising the steps of: 11 applying an adhesive sealant to at least one of 12 the abutting portions; and 13 positioning the first and second gutter 14 sections such that the abutting portion of the first 15 gutter section abuts the corresponding abutting 16 portion of the second gutter section such that the 17 first and second gutter sections are fixed together 18 by said adhesive sealant.

19 20 In a preferred embodiment, the abutting portion of 21 the first gutter section comprises a joggle portion, 22 and the abutting portion of the second gutter 23 section comprises a projecting shelf, wherein the 24 adhesive sealant is applied to the joggle portion 25 such that the shelf is adhered thereto.

26 27 Preferably, the method comprises the further step of 28 adapting the joggle portion to provide a barrier 29 means for retaining the adhesive sealant on the 30 joggle section. Preferably, said barrier means 31 comprises a stopper fixed to the joggle portion.

1 Alternatively, said barrier means comprises one or 2 more shaped troughs.

3 4 Preferably, the method further comprises a further 5 step of applying an additional quantity of adhesive 6 sealant between the joggle section and shelf 7 following the positioning step.

8 9 In a second preferred embodiment, the adhesive 10 sealant is applied to the abutting portions of both 11 the first and second gutter sections by way of an 12 adhesive sealant-coated butt strap adapted to be 13 fixed to the first and second gutter sections.

14 15 Preferably, one of the first or second gutter 16 sections has a projecting flange extending at least 17 partially around the outer perimeter of the abutting 18 portion of the gutter section, the outer surface of 19 the other gutter section adjacent the abutting 20 portion being positioned on said flange during the 21 positioning step.

22 23 Preferably, the adhesive sealant is a modified 24 silicon structural sealant having a breaking 25 strength greater than IN/mm and most preferably 26 greater than 2N/mm2.

27 28 Preferably, the adhesive sealant has a maximum 29 allowed distortion of I25%. Preferably, the 30 adhesive sealant has a modulus of elasticity in the 31 range 0.5-1. 5N/mm2 and most preferably in the range 32 0.75-1. 5N/mm2.

1 2 An embodiment of the invention will now be described 3 with reference to the accompanying drawings in 4 which: 5 6 Figure 1 is a section view through a first 7 embodiment of a gutter expansion joint; 8 9 Figures 2 (a)- (c) show the steps of a method of 10 constructing the expansion joint of Figure 1; 11 12 Figure 3 shows a section view through a second 13 embodiment of the gutter expansion joint; 14 15 Figures 4 (a)- (d) show the steps of a method of 16 constructing the expansion joint of Figure 3; 17 18 Figure 5 shows a section view through a third 19 embodiment of the gutter expansion joint; and 20 21 Figures 6 (a)- (d) show the steps of a method of 22 constructing the expansion joint of Figure 5.

23 24 Referring initially to Figure 1, a first embodiment 25 of an expansion joint for joining sections of an 26 insulated modular gutter is generally depicted at 1.

27 The view shown is a section view through the base of 28 the gutter sections, with the remaining portions of 29 the gutter removed for illustrative purposes. The 30 expansion joint 1 comprises first and second gutter 31 sections 3,5 which each have an abutting portion 32 which abuts the corresponding abutting portion of

1 the other gutter section. In this first embodiment, 2 the abutting portion of the first gutter section 3 3 is a joggle portion 2, and the abutting portion of 4 the second gutter section 5 is a projecting shelf 4.

5 6 The joggle portion 2 is formed by an indentation or 7 notch in the first gutter section 3 which contains 8 two generally U-shaped troughs 6 and 7. These U- 9 shaped troughs 6 and 7 are employed to house a 10 structural adhesive sealant 8 that acts to bond the 11 gutter sections 3 and 5 together while producing a 12 watertight seal between them. The dimensions of the 13 U-shaped troughs 6 and 7 are chosen such that the 14 structural adhesive sealant 8 is maintained at an 15 optimum thickness so as produce the adhesive, 16 watertight and expansion properties required for the 17 expansion joint 1.

18 19 Figures 2 (a)- (c) present the three steps required to 20 form the first embodiment of the gutter expansion 21 joint joining the first and second gutter sections 22 3,5 together. These steps involve: 23 24 1. a first quantity of structural adhesive sealant 25 8 being applied to fill the second U-shaped 26 trough 7 of the joggle portion 2 of the first 27 gutter section 3, as depicted in Figure 2 (a); 28 29 2. the second gutter section 5 then being 30 positioned so as to abut the first gutter 31 section 3, such that the shelf 4 of the second 32 gutter section 5 locates across the top of the

1 joggle portion 2 of the first gutter section 3 2 thereby contacting the adhesive sealent 8 in 3 the trough 7, as depicted in Figure 2 (b); and 4 5 3. a second quantity of structural adhesive 6 sealant 8 then being applied at the interface 7 of the shelf 4 of the second gutter section 5 8 and an edge portion of the first U-shaped 9 trough 6 of the first gutter section 3, as 10 depicted in Figure 2 (c).

11 12 Figures 3 and 4 (a)- (d) show a modified embodiment of 13 the gutter expansion joint described above. Again, 14 the view shown is a section view through the base of 15 the gutter sections, with the remaining portions of 16 the gutter removed for illustrative purposes. The 17 modified expansion joint 10 comprises first and 18 second insulated modular gutter sections 13,15. As 19 before, the first gutter 13 is provided with an 20 abutting portion in the form of a joggle portion 12 21 while the second gutter 15 has an abutting portion 22 in che form of a shelf 14.

23 24 Where this embodiment differs from the first 25 embodiment is that in place of the trough 26 arrangement on the joggle portion 12 there is a 27 plastic stopper 16 located at the leading edge of 28 the joggle portion 12 of the first gutter 13. The 29 stopper 16 retains the structural adhesive sealant 30 18 in the joggle portion 12 such that the first and 31 second gutters may be bonded together to produce a 32 watertight expansion joint.

1 2 Figures 4 (a)- (d) show the steps to achieving the 3 expansion joint of the second embodiment. The steps 4 involve: 5 1. applying the stopper 16 at the leading edge of 6 a joggle portion 12 of the first gutter section 7 13 to retain the adhesive sealant 18, as 8 depicted in Figure 4 (b) ; 9 10 2. applying a quantity of adhesive sealant 18 to 11 fill the joggle portion 12 of the first gutter 12 13, as depicted in Figure 4 (c) ; 13 14 3. positioning the second gutter 15 so as to abut 15 the first gutter 13, such that the shelf 14 of 16 the second gutter 15 locates across the top of 17 the joggle portion 12 of the first gutter 13 18 and contacts the adhesive sealant 18 in the 19 joggle portion 12, as depicted in Figure 4 (d).

20 21 Figures 5 and 6 (a)- (d) show a third embodiment of 22 the gutter expansion joint. As with the previously 23 described embodiments, the view shown is a section 24 view through the base of the gutter sections, with 25 the remaining portions of the gutter removed for 26 illustrative purposes. The expansion joint 20 27 comprises first and second gutter sections 23,25, 28 but unlike the previously described embodiments, 29 neither the first or second gutters 23,25 has a 30 joggle portion. Instead, this embodiment utilises 31 an adapted butt strap arrangement.

32

1 The joint is formed between the abutting first and 2 second gutters 23,25 by applying the adhesive 3 sealant 28 to a butt strap 30 which is then 4 positioned so as to be across the join of the 5 abutting gutters 23,25. Adhesive tape 27 is placed 6 across the join prior to the application of the butt 7 strap 30 to prevent ingress of adhesive sealant 28 8 into the join. The second gutter 25 has a flange 24 9 upon which the first gutter is positioned to 10 facilitate the creation of the joint.

11 12 With reference to Figures 6 (a)- (d), the method steps 13 of achieving the third embodiment of the gutter 14 expansion joint are shown. The steps comprise: 15 16 1. Positioning the first gutter 23 upon the flange 17 24 of the second gutter 25 such that an 18 abutting portion of the second gutter 25 abuts 19 a corresponding abutting portion of the first 20 gutter 23, as depicted in Figure 6 (a); 21 22 2. applying an adhesive tape 27 across the join of 23 the abutting gutters 23,25 so as to prevent 24 sealant adhesive from entering the join between 25 the gutters 23,25, as depicted in Figure 6 (b); 26 27 3. affixing plastic stoppers 26 to each end of a 28 butt strap 30, and inverting the butt strap 30 29 so as to apply a quantity of adhesive sealant 30 28 to the underside of the butt strap 30, as 31 depicted in Figure 6 (c); and 32

1 4. righting the butt strap arrangement and 2 affixing it to the abutting portions of the 3 first and second gutters 23,25 so that the butt 4 strap 30 is positioned over the join of the 5 abutting first and second gutters 23,25 and 6 adhesive tape 27, as depicted in Figure 6 (d).

7 8 In this way, a watertight expansion joint is 9 produced without the need to apply mechanical 10 fixings to either of the first and second gutters.

11 12 A suitable structural adhesive sealant for use in 13 each of the embodiments described above is a 14 modified silicon sealant, based upon MS Polymer.

15 The sealant has a breaking strength greater than 16 1N/mm2 and preferably greater than 2N/mm2. In 17 tests, it has been found that the sealant may 18 optimally have a breaking strength of 2. 2N/mm2.

19 Furthermore, the sealant may distort by up to 25%.

20 In other words, the sealant may expand or contract 21 by up to 25% without any breakage or adverse effects 22 upon its performance. To permit this distortion, 23 the sealant has a modulus of elasticity of between 24 0. 5N/mm2 and 1. 5N/mm2. Tests have shown that a 25 modulus of elasticity of between 0. 75N/mm2 and 26 1. 5N/mm2 is preferable, and that a modulus of 27 elasticity of 1. 3N/mm2 is best for this application.

28 Additionally, the structural adhesive sealant is 29 temperature resistant between-40 C and +90 C.

30 31 The adhesive sealant is resistant to water and, 32 thanks to the properties discussed above, it can

1 flex and expand when placed under stress or strain 2 to maintain the joint. This is in contrast to 3 sealants currently used in this field which are not 4 intended to offer adhesive properties because 5 mechanical fixings secure the gutter components 6 together.

7 8 When applied, the structural adhesive sealant 9 maintains contact with the gutters at all times so 10 rendering the expansion joint watertight. Ideally, 11 a surface activator is applied to the surface 12 initially to remove any moisture, grease or the like 13 from the surface. This ensures a good initial 14 contact between the sealant adhesive and the 15 gutters.

16 17 The structural adhesive sealant exhibits a reliable 18 tensile strength that is capable of pulling down the 19 unloaded section of the gutter adjacent to the 20 expansion joint. It offers a high initial tack thus 21 removing the requirement for initial support when 22 applied to the expansion joint.

23 24 The present invention has the advantage that it 25 provides a reliable and quickly-assembled watertight 26 expansion joint that does not require the employment 27 of mechanical fixings, and can be easily assembled 28 on site. The adhesive sealant used has a 29 combination of strength and elasticity superior to 30 conventional sealants. This allows the adhesive 31 sealant to be used for the joint where the 32 conventional sealants would be unsuitable.

1 2 Modifications and improvements may be incorporated 3 without departing from the scope of the invention.

Claims

CLAIMS:

1 1. A gutter expansion joint comprising first and

2 second gutter sections, the first gutter

3 section having an abutting portion which abuts

4 a corresponding abutting portion on the second

5 gutter section, wherein at least one of the

6 abutting portions has an adhesive sealant

7 applied thereto such that the first and second

8 gutter sections are fixed together by said

9 adhesive sealant.

10 11
2. The expansion joint of Claim 1, wherein the 12 abutting portion of the first gutter section 13 comprises a joggle portion, and the abutting 14 portion of the second gutter section comprises 15 a projecting shelf, wherein the adhesive 16 sealant is applied to the joggle portion such 17 that the shelf is adhered thereto.

18 19
3. The expansion joint of Claim 2, wherein the 20 joggle portion has barrier means for retaining 21 the adhesive sealant thereon.

22 23
4. The expansion joint of Claim 3, wherein the 24 barrier means comprises a stopper fixed to the 25 joggle portion.

26 27
5. The expansion joint of Claim 3, wherein the 28 barrier means comprises one or more shaped 29 troughs.

30

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1
6. The expansion joint of Claim 1, wherein both

2 abutting portions have adhesive sealant applied

3 thereto, the joint further comprising a butt

4 strap positioned over the joint and fixed to

5 the abutting portions of the first and second

6 gutter sections by the adhesive sealant.

7

8
7. The expansion joint of any preceding claim,

9 wherein one of the first and second gutter 10 sections has a projecting flange extending at 11 least partially around the outer perimeter of 12 the abutting portion of the gutter section, the 13 outer surface of the other gutter section 14 adjacent the abutting portion being positioned 15 on said flange.

16 17
8. The expansion joint of any preceding claim, 18 wherein the adhesive sealant is a modified 19 silicon structural sealant.

20 21
9. The expansion joint of any preceding claim, 22 wherein the adhesive sealant has a breaking 23 strength greater than IN/mm2.

24 25
10. The expansion joint of any preceding claim, 26 wherein the adhesive sealant has a breaking 27 strength greater than 2N/mm2.

28 29
11. The expansion joint of any preceding claim, 30 wherein the adhesive sealant has a maximum 31 allowed distortion of 25%.

32

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1
12. The expansion joint of any preceding claim,

2 wherein the adhesive sealant has a modulus of

3 elasticity in the range 0.5-1. 5N/mm2.

4

5
13. The expansion joint of any preceding claim,

6 wherein the sealant has a modulus of elasticity

7 in the range 0.75-1. 5N/mm2.

8

9
14. A method of forming a gutter expansion joint 10 from first and second gutter sections, the 11 first gutter section having an abutting portion 12 adapted to abut a corresponding abutting 13 portion on the second gutter section, the 14 method comprising the steps of: 15 applying an adhesive sealant to at least 16 one of the abutting portions; and 17 positioning the first and second gutter 18 sections such that the abutting portion of the 19 first gutter section abuts the corresponding 20 abutting portion of the second gutter section 21 such that the first and second gutter sections 22 are fixed together by said adhesive sealant.

23 24
15. The method of Claim 14, wherein the abutting 25 portion of the first gutter section comprises a 26 joggle portion, and the abutting portion of the 27 second gutter section comprises a projecting 28 shelf, wherein the adhesive sealant is applied 29 to the joggle portion such that the shelf is 30 adhered thereto.

31

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1
16. The method of Claim 15, comprising the further

2 step of adapting the joggle portion to provide

3 a barrier means for retaining the adhesive

4 sealant on the joggle section.

5

6
17. The method of Claim 16, wherein said barrier

7 means comprises a stopper fixed to the joggle

8 portion.

9 10
18. The method of Claim 16, wherein said barrier 11 means comprises one or more shaped troughs.

12 13
19. The method of any of Claims 15 to 18, further 14 comprising the step of applying an additional 15 quantity of adhesive sealant between the joggle 16 section and shelf following the positioning 17 step.

18 19
20. The method of Claim 14, wherein the adhesive 20 sealant is applied to the abutting portions of 21 both the first and second gutter sections by 22 way of an adhesive sealant-coated butt strap 23 adapted to be fixed to the first and second 24 gutter sections.

25 26
21. The method of either of Claims 14 or 20, 27 wherein one of the first or second gutter 28 sections has a projecting flange extending at 29 least partially around the outer perimeter of 30 the abutting portion of the gutter section, the 31 outer surface of the other gutter section

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1 adjacent the abutting portion being positioned

2 on said flange during the positioning step.

3

4
22. The method of any of Claims 14 to 21, wherein

5 the adhesive sealant is a modified silicon

6 structural sealant.

7

8
23. The method of any of Claims 14 to 22, wherein

9 the adhesive sealant has a breaking strength 10 greater than 1N/mm2.

11 12
24. The method of any of Claims 14 to 23, wherein 13 the adhesive sealant has a breaking strength 14 greater than 2N/mm2.

15 16
25. The method of any of Claims 14 to 24, wherein 17 the adhesive sealant has a maximum allowed 18 distortion of 25%.

19 20
26. The method of any of Claims 14 to 25, wherein 21 the adhesive sealant has a modulus of 22 elasticity in the range 0.5-1. 5N/mm2.

23 24
27. The method of any of Claims 14 to 26, wherein 25 the adhesive sealant has a modulus of 26 elasticity in the range 0. 75-1. 5N/mm2.

27 28
28. A gutter expansion joint substantially as 29 hereinbefore described with reference to the 30 accompanying drawings.

31

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1
29. A method of forming a gutter expansion joint 2 substantially as hereinbefore described with 3 reference to the accompanying drawings.