GB2528132A

GB2528132A - Construction membrane and intermittent tape

Info

Publication number: GB2528132A
Application number: GB1412405.1A
Authority: GB
Inventors: Neil Murray Rideout
Original assignee: Building Product Design Ltd
Current assignee: Building Product Design Ltd
Priority date: 2014-07-11
Filing date: 2014-07-11
Publication date: 2016-01-13
Anticipated expiration: 2034-07-11
Also published as: GB2528132B; GB201412405D0

Abstract

A construction membrane with a lap portion 18, for overlapping another construction membrane, with a plurality of adhesive regions 12 and nonÂadhesive regions 14 thereon. The adherable regions and nonÂadherable regions may be in the form of a tape and may be covered by a release liner 16. The adhesive may be thermoplastic synthetic rubber or be polyolefin or modified acrylic based and may be UV stabilised and/or heat stabilised. The nonadhesive regions may be regions of silicone. The liner may be waxed paper, polyester or polypropylene and may comprise a silicone layer. The membrane may be constructed of polyolefins and/or be bitumen-based. The membrane may be a roof underlay. A roof or wall may be made from a plurality of membranes adhered together in an overlap region. The nonadhesive regions allow gaps for ventilation; this allows water vapour to escape but resists wind uplift.

Description

Construction Membrane and Intermittent Tape

Technical Field of the Invention

The present invention relates to intermittent adhesive tapes for construction membranes and construction membranes comprising iriLermitLent adhesives.

Background to the Invcntion

The concept of scaling roof construction mcnibrancs, such as roof underlays. at their overlaps with continuous adhesive tapes is well known and has been used on roof and wall mcmbrancs for many ycars. The technique has bccn iscd with various underlays, induding roof undedays with vapour permeable qualities, particuar1y in Europe. Figure 1 shows an example of a conventional sealed lap membrane, in which a first membrane 1 has been laid on rafters 2 before tiling battens 3 are fixed to the rafters over the first membrane 1. A release layer has been removed to reveal an adhesive strip 4 and a second membrane S is being laid over the first membrane 1, such that it overlaps the adhesive strip 4.

Sealing the laps of construction membranes/roof underlays in this known, continuous, manner can be seen as having two benefits; 1. It prevents any blown water or snow from entering the main roofspace.

2. It assists in the prevention ofwind uplifi to which a roof underlay is subjected when installed. Roof irnderlays will balloon or deflect upwards particularly on the leeward side of a roofwhen absorbing aproportion ofthc tota' wind load on a roof This dcflcction is most pronounccd at the overlap of the underlay. Scaling the laps will rcsist this deflection.

Despite these advantages, construction membranes/roof underlays are commonly not scaled as it is accepted that certain types of roof and wall construction, in particular those known as "cold roofs", with a large attic void require to be ventilated to prevent the risk of harmthl condensation. The cold roof concept is still common in the UK and in parts of Europe.

It is well known that the unsealed laps of external construction membranes/roof underlays allow some ventilation and water vapour escape through the interface in addition to the ventilation provisions recommended for the roof void. To seal the underlay lap completely would require additional ventilation provision to be provided elsewhere to make it up.

This applies to both vapour permeable and non-vapour permeable membranes.

Whichever technique is used, there are disadvantages, not least in the fact that the advantages of the alternative approach are not achieved.

The present invention seeks to overcome or at least alleviate some of the

disadvantages of the prior art.

Summary of the Invention

According to a first aspect of the invention, there is provided a construction membrane having a lap portion for overlapping with the lap portion of another construction membrane, wherein the lap portion comprises a plurality of spaced adhesive regions, with a plurality of non-adhesive gaps therebetween.

With this structure, the overlapping portions of construction membranes are partially sealed together in the adhesive regions, but gaps remain in the non-adhesive regions. The fact that some regions of overlapping construction membranes are sealed to each other prevents, or at least ameliorates blown water/snow entering a roofspace (or another space behind the membranes) and resists wind-uplift. However, because of the gaps between the adhesive regions, through which water vapour can escape. the risk of harniful condensation is reduced and the need to increase ventilation provision is obviated.

The construction membrane may be roof underlay. The advantages are especially pertinent when the membrane is used as an underlay for roofs, and of most advantage when the underlay is used in the construction of "cold roofs".

The adhesive regions may be covered by a release liner. This allows for easier handling. The release liner may bc waxed paper, polyester or polypropylene. The release liner may he provided with a silicone layer to case removal from the adhesive.

The release liner may cover the adhesive regions and gaps therebetween. This allows simple removal of the liner from multiple adhesive regions.

The adhesive regions may be applied to the construction membrane in the form of a tape. This allows for a more simple addition during the construction process than applying adhesive and release liners separately, directly to the construction membrane.

The tape may cover the adhesive and non-adhesive regions. In particular when the tape is provided with a release liner, this is advantageous in allowing one movement removing the release liner to unveil more than one adhesive region.

The tape may comprise a release liner, an adhesive layer provided on the release liner and a non-adhesive coating provided intermittently on the adhesive layer of the tape, whereby when the tape is applied to the construction membrane, those parts of the tape that are provided with a non-adhesive coating adhere more strongly to the release liner than to the construction membrane, so as to form gaps between adhesive regions when the release liner is removed. Alternatively, the non-adhesive regions may he provided by applying silicone or the like intermittently along the lap portion in the region where the tape will be placed. so that the adhesive only adheres to the lap portion in the regions where silicone or the like is absent, in order to fbrm adhesive regions between the silicone and gaps where the silicone is present.

The adhesive may be a thermoplastic synthetic rubber adhesive and may be TJV and/or heat stabilised. Alternatively, the adhesive may be a polyolefin based adhesive or a modified acrylic based adhesive.

The adhesive regions may each be about 100mm long and may be about 50- 100mm wide. The adhesive regions are preferably at least 20mm long, more preferably at least 50mm. most preferably at least 90mm long. They are preferably less than 500mm long, more preferably less than 200mm long and most preferably less than 110mm long.

They are suitably 100mm long. The adhesive regions are preferably at least 15mm wide, more preferably at least 25 mm wide and most preferably at least 50mm wide. They are preferably less than 500mm wide, more preferably less than 200mm wide and most preferably less than 100mm wide. They are suitably 75mm wide.

Thc gaps between thc adhcsivc regions may bc about 100mm long. Thc gaps arc preferably at least 20mm long, more preferably at least 50mm. most preferably at least 90mm long. They are preferably less than 500mm long, more preferably less than 200mm long and most preferably less than 110mm long. They are suitably 100mm long.

The adhesive regions may have a weight of 50-125 grams per square metre, preferably between 50 and 75 grams per square metre.

The lap portion may extend from an edge of the construction membrane and the leading edge of the adhesive regions may be no more than 50mm inwards from the edge.

preferably no more than 25mm inwards from the edge.

The membrane may be constructed of polyolefins.

Alternatively the membrane may be bitumen-based.

The adhesive may be a contact adhesive or pressure sensitive adhesive -this avoids any need for activation.

In a second aspect of the invention, there is provided a roof or wall comprising a plurality of construction membranes, the construction membranes adhered together in an overlap region by a plurality of regions of adhesive with a plurality of non-adhesive gaps therebetween.

The roof or wall may be a cold roof In a third aspect of the invention, there is provided a method of manufacturing a construction membrane as set out above; the method comprising: advancing a web of membrane material, applying an adhesive to the surface ofthc advancing web; slitting the web transversely; and rolling the slit webs into rolls of construction membrane; wherein the adhesive is provided as a plurality of spaced adhesive regions. ivith a plurality of non-adhesive gaps therebetween.

The adhesive may be applied intermittently directly to the membrane. A release liner may be applied over the adhesive regions.

Alternatively, the adhesive may applied to the membrane in the form of a tape.

In a fourth aspect of the invention, there is provided a tape for connecting construction mcmbrancs so as to allow a gap for vcntilation; thc tape comprising a release liner having spaced adhesive regions with non-adhesive gaps therebetween.

The release liner may be polyester or polypropylene. The release liner may be provided with a silicone layer to ease removal from the adhesive.

The adhesive may be a thermoplastic synthetic rubber adhesive and may be LIV andlorheat stabilised. Alternatively, the adhesive may be a polyolefin based adhesive or a modified acrylic based adhesive.

The adhesive regions may each be about 100mm long and may be about 50- 100mm wide. The adhesive regions are preferably at least 20mm long, more preferably at least 50mm, most preferably at least 90mm long. They are preferably less than 500mm long, more preferably less than 200mm long and most preferably less than 110mm long.

The gaps between the adhesive regions may be about 100mm long. The gaps are preferably at least 20mm long, more preferably at least 50mm, most preferably at least 90mm long. They are preferably less than 500mm long, more preferably less than 200mm long and most preferably less than 110mm long. They are suitably 100mm long.

The non-adhesive gaps preferably are provided by regions in which no adhesive is applied to the tape. Alternatively, they arc provided by coating the adhesive, such that the coated regions are not adhesive.

In a further aspect of the invention, there is provided a construction membrane having a lap portion for overlapping with the lap portion of another construction mcmbrane, wherein the lap portion comprises a plurality of spaced adherable regions, with a plurality of non-adherable gaps therebetween. Such a construction membrane may be used in conjunction with a conventional membrane with adhesive tape, because the non-adherable gaps will not adhere to the tape, whereas the adherable regions will adhere to the tape. Thus some regions of overlapping construction membranes arc sealedto each other to prevent, or at least ameliorate blown water/snow entering a roofspace (or another space behind the membranes) and resist wind-uplifi. However, gaps will be provided between the adhesive regions, through which water vapour can escape, thereby reducing the risk of harmful condensation and obviating the need to increase ventilationprovision.

The non-adherable regions may be provided by regions of silicone applied to the lap portion. The non adherable regions maybe spaced to provide adherable regions and non-adherable gaps ofthe same length as the adhesive and non-adhesive gaps discussed above, i.e. they are preferably at least 20mm long, more preferably at least 50mm, most preferably at least 90mm long. They are preferably less than 500mm long, more preferably less than 200mm long and most preferably less than 110mm long. They are suitably I 00mm long.

The non-adherablc regions should he wider though; at least 50mm, preferably at least 100mm and more preferably at least 200mm wide, to ensure that if the overlap is not precise, the adhesive on an overlying construction membrane registers with the non-adhcrablc regions of the underlying construction membrane.

Detailed Description of the Invention

In order thaL the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows a prior art sealed lap membrane being installed on a roof'; Figure 2 shows a construction membrane according to thc invention with a release layer partially removed; Figure 3 shows a construction membrane as shown in figure 2 being installed on a roof Figure 4 shows schematically an apparatus for forming the construction membranes shown in figures 2 and 3; Figure 5 shows schematically an alternative apparatus for forming the construction membranes shown in figures 2 and 3; and Figure 6 shows schematically a further apparatus for forming the construction membranes shown in figures 2 and 3.

Referring to figure 2, a roll 32 of construction membrane, in this embodiment, roof underlay 10 formed of polyolefins e.g.a laminated construction of polypropylene spunbond upper layer, polypropylene breathable film intermediate layer and polypropylene spunbond lower layer is shown partially unrolled. The roll may be 50 metres long and 1.5 metre wide. Along one long side of the roll, there is a lap portion 18, which in use will overlap with the lap portion of another such construction membrane. In this lap portion 18, adhesive regions 12 are formed. The adhesive may suitably be thermoplastic synthetic rubber and is coated at 75 grams per square metre. The adhesive regions are I 00mm long and 50mm wide. They are separated from each other by gaps 14 which arc also about 100mm long, where no adhesive is applied. The adhesive regions 12 arc formed 25mm inward from the edge of the long side of the roll and as they arc 50mm wide, they extend to 75mm inward from the edge. The adhesive regions 12 are covered by a polycster release liner 16 with a silicone release layer (not shown).

Referring to figure 3, in use a first strip ofroofundcrlay lOis rolled out laterally over the rafiers 2 of a roof and battens 3 are fixed to the rafters to sandwich the underlay in between the rafters 2 and the battens 3. Care is taken to orient the strip of roof underlay 10 such that the adhesive regions 12 are on the upper side of the roof underlay 10, at the top end. The release liner 16 (not shown) is removed to reveal the adhesive regions 12 and the gaps 14 thcrchctwccn. Then another roll of roof underlay lOis rolled out above the first strip such that a lap portion 20 at its bottom end overlaps the lap portion 18 at the upper end of the first strip. The underside of the second strip of roof underlay 10 is thereby partially adhered to the upper side of the first strip of roof underlay 10 but gaps are provided in the non-adhesive regions 14. This process is continued until the raflers are covered with underlay 10 and tiling battens 3 are in place.

The roof may then be tiled.

One niethod of forming the construction niembranes 10 according to the invention will now be described with reference to figure 4. First, a 50mm wide tape is formed by applying adhesive to a silicone release layer formed on one surface of a backing layer (release liner) 16 of polyester/polypropylene. The opposite surface of the backing layer 16 has a second silicone release layer on it, the second release layer having a greater release capacity than the first. The adhesive is applied via a slot coating head, which may be a 100mm wide head, with a shim in thc centre to make two 50mm widc tapes side by side. The slot coating head opens and closes intermittently as the tape passes, in order to deliver intermittent adhesive of 100mm in length, and 100mm gaps in between. The tape is then wound into rolls 22, with the second release layer facing outward.

Referring to figure 4. jumbo rolls" of double width membrane 24. twice as wide as the roll of roof underlay 10, are unwound over tension/guide rollers 26 through a nip 28 provided by two further rollers 26. At the nip 28, tape from two tape rolls 22 is applied to the upper surface of the membrane 24 proximal to each respective edge. The membrane then passes under a further tension roller 26, which presses the adhesive surface of the tape against the surface of the membrane 24. The membrane then advances over a further tension roller 26 to a slitter 30 which slits the membrane 24 down the middle to form two finished membranes 10, each of which has a lap portion 18 on which the tape is formed. The finished membrane 10 then passes under and over two more tension rollers 26 before being wound into finished rolls 32. The finished rolls 32 of membrane 10 are cut laterally along transverse cut lines 34 and removed once they reach a commercially saleable length of about SOni. The adhesive regions 12 adhere strongly to the membrane 10, such that when the backing layer 16 is later removed, they remain on the membrane 10. not the backing layer 16.

Referring to figure 5, an alternative method of forming rolls 32 of construction membrane lOis shown, in this case, the double width "jumbo rolls" 24 referred to above are first cut down the middle to form two "half-width jumbo rolls" 25, each as wide as the roll 32 of roof underlay 10. One of these half width jumbo rolls 25 is mounted and a similar method is carried out, in which the half width jumbo roll 25 is unwound over tensioniguidc rollers 26 through a nip 28 provided by two further rollers 26. At the nip 28, tape from a tape roll 22 is applied to the upper surface of the membrane 24 proximal to one edge. The membrane then passes under a further tension roller 26, which presses the adhesive surface of the tape against the surface of the membrane 24. The membrane then advances over a further tension roller 26 before being wound into a finished roll 32.

The finished roll 32 of membrane 10 is cut laterally along a transverse cut line 34 and removed once it reaches a commercially saleable length of about 5Dm. The adhesive regions 12 adhere strongly to the membrane 10, such that when the backing layer 16 is later removed, they remain on the membrane 10, not the backing layer 16.

In yet another method of manufacturing the rolls 32 of roof underlay 10, shown in figure 6, a half-widthjumbo roll" 25 is mounted and unrolled. As the roll 25 is unrolled, it passes a slot coating head 36 which is controlled by a control circuit (not shown) to intermittently dispense adhesive onto the upper surface of the roof underlay 10 proximal to one of its edges, so as to form adhesive regions 12, with non-adhesive gaps 14 in between. The roof underlay 10 then advances towards a nip 28 provided by two further rollers 26. At the nip 28, release liner 16 from a release liner roll 38 is applied to the upper surface of the membrane on top of the adhesive 12 (and over the non-adhesive regions 14 in between). The membrane then passes under a flirther tension roller 26, which presses the surface of the release liner against the adhesive surface of the membrane 10. The membrane then advances over a further tension roller 26, under another tension roller 26 and over a final tension roller 26 before being wound into a finished roll 32. The finished roll 32 of membrane lOis cut laterally along a transverse cut line 34 and removed once it reaches a commercially saleable length of about 50m.

The adhesive regions 12 adhere strongly to the membrane 10, such that when the release liner 16 is later removed, they remain on the membrane 10. not the release liner 16.

The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims. For example, whilst the gaps are described as being formed by leaving gaps where no adhesive is applied to the membrane, the gaps could be provided by applying a continuous tape to the membrane, but applying silicone either to regions of the underside of the tape, or to the upper side of the membrane sich that those regions coated in silicone remain attached to the release liner, rather than the membrane, thereby forming the gaps as the r&ease liner is removed. Similarly, whflst in the embodiment the adhesive is shown on the upper side of the lap portion of a construction membrane which sits underneath another membrane in use, the adhesive could instead be formed on the underside of an ovedying construction membrane.

Claims

CLAIMS1. A construction membrane having a lap portion for overlapping with the lap portion of another construction membrane, wherein the lap portion comprises a plurality of spaced adhesive regions, with a plurality of non-adhesive gaps therebetween.
2. A construction membrane according to claim 1 which is roof underlay.
3. A construction membrane according to claim 1 or 2 wherein the adhesive regions may be covered by a release liner.
4. A construction membrane according to claim 3 wherein the release liner is waxed paper, polyester or polypropylene.
5. A construction membrane according to claim 3 or 4 wherein the release liner comprises a silicone layer on one surface.
6. A construction membrane according to any of claims 3 to 5 wherein the release liner covers the adhesive regions and gaps therebetween.
7. A construction membrane according to any of the preceding claims wherein the adhesive regions are in the form of a tape applied to the construction membrane.
8. A construction membrane according to claim 7 wherein the tape is provided with adhesive and non-adhesive regions.
9. A construction membrane according to any of the preceding claims wherein the adhesive is a thermoplastic synthetic rubber adhesive.
10. A construction membrane according to any of the preceding claims wherein the adhesive is a polyolefin based adhesive or a modified acrylic based adhesive.
11. A construction membrane according to any of the preceding claims wherein the adhesive is liv and/or heat stabiliscd.
12. A construction membrane according to any of thc prcccding claims whcrcin thc adhesive regions are each about 100mm long and about 50-100mm wide.
13. A construction membrane according to any of the preceding claims wherein the gaps between the adhesive regions are about 100mm long.
14. A construction membrane according to any of the preceding claims wherein the adhesive regions may have a weight of 50-125 grams per square metre.
15. A construction membrane according to any of the preceding claims wherein the lap portion extends from an edge of the construction membrane and the leading edge of the adhesive region is no more than 25mm inwards from the edge.
16. A construction membrane according to any of the preceding claims wherein the membrane is constructed of polyolefins.
17. A construction membrane according to any of the preceding claims wherein the membrane is bitumen-based.
18. A construction membrane according to any of the preceding claims wherein the adhesive is a contact adhesive or pressure sensitive adhesive
19. A roof or wall comprising a plurality of construction membranes, thc construction membranes adhered together in an overlap region by a plurality of regions of adhesive with a plurality of non-adhesive gaps therebetween.
20. A roof or wall according to claim 19 which is a cold roof
21. A method of manufacturing a construction membrane according to any of claims 1 to 18; thc method comprising: advancing a wcb of membrane material.applying an adhesive to the surface of the advancing web; slitting the web transversely; and rolling the slit webs into rolls of construction membrane; wherein the adhesive is provided with a plurality of spaced adhesive regions, with a plurality of non-adhesive gaps therebetween.
22. A method according to claim 21 wherein the adhesive is applied intermittently directly to the membrane.
23. A method according to claim 22 thrther comprising applying a release liner over the adhesive regions.
24. A method according to claim 21 wherein the adhesive is applied to the membrane in the form of a tape.
25. A tape for connecting construction membranes so as to allow a gap for ventilation; the tape comprising a release liner having spaced adhesive regions with non-adhesive gaps therebetween.
26. A tape according to claim 25 wherein the release liner comprises polyester or polypropylene.
27. A tape according to claim 25 or 26 wherein the release liner is provided with a silicone layer to ease removal from the adhesive.
28. A tape according to any of claims 25 to 27 wherein the adhesive is a thermoplastic synthetic rubber adhesive
29. A tape according to any of claims 25 to 27 wherein the adhesive is a polyolefin bascd adhcsivc or a modified acrylic bascd adhesive.
30. A tape according to any of claims 25 to 28 wherein the adhesive is UV and/or heat stabilised.
31. A tape according to any of claims 25-30 wherein the adhesive regions are each about 100mm long and about 50-100mm wide.
32. A tape according to any of claims 25 to 31 wherein the gaps between the adhesive regions are about 100mm long.
33. A tape according to any of claims 25 to 32 wherein the adhesive regions have a weight of 50-125 grams per square metre.
34. A construction membrane having a lap portion for overlapping with the lap portion of another construction membrane, wherein the lap portion comprises a plurality of spaced adherable regions, with a plurality of non-adherable gaps therebetween.
35. A construction membrane according to claim 34 wherein the non-adherable regions are provided by regions of silicone applied to the lap portion.
36. A construction membrane, a tape or a roof or wall substantially as described herein with reference to the accompanying drawings.