GB2368814A

GB2368814A - Laminated sheet or board as building material

Info

Publication number: GB2368814A
Application number: GB0027161A
Authority: GB
Inventors: Roderick Dakin
Original assignee: Celotex Ltd
Current assignee: Celotex Ltd
Priority date: 2000-11-07
Filing date: 2000-11-07
Publication date: 2002-05-15
Anticipated expiration: 2020-11-07
Also published as: GB2368814B; GB0027161D0

Abstract

A laminated sheet or board (49) as a building material comprises a primary sheet or board (50), and a secondary sheet (51) of flexible material which is bonded face to face with the primary sheet or board, both the primary sheet or board and the secondary sheet or board and the secondary sheet being building materials. At least adjacent one edge of the primary sheet or board, the secondary sheet is bonded during manufacture to the primary sheet or board using an adhesive (52) which allows that area of the flexible sheet to be peeled away from the primary sheet without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet.

Description

LAMINATED SHEET OR BOARD AS BUILDING MATERIAL

This invention relates to laminated sheet or board as a building material. More particularly but not exclusively, the invention relates to laminated sheet or board used in building applications, having a first component which is substantially rigid and a second component which is flexible. The use of the term rigid material is deemed to include substantially rigid material.

Rigid sheet or board materials-of rectangular shape are commonly used in the construction of buildings. They are to be found on top of joists as flooring or flat roof decking ; underneath joists as ceilings ; inside the studs of frame construction or roof rafters as an exposed lining; on the outside of the studs of a frame construction and on top of rafters as a sheathing-also known as sarking on top of rafters-and on the inside of rafters or studs, but under any linings, also as a sheathing. Their purpose may be to present a trafficable surface; to present a decorateable surface; improve weathertightness; provide improved fire resistance; provide wind bracing (improve racking strength); provide thermal or acoustic insulation. In some instances they serve more than one purpose.

Insulation sheet or board is also used for a floating floor and under a cement screed or concrete slab.

Typically, but not exclusively, these rigid sheet or board materials consist of paper-faced gypsum, fibre reinforced gypsum, plywood, bonded wood particles or strands (chipboard and oriented strand board), bonded cellulose fibres (softboard, medium board, hardboard) and faced or unfaced foams including polyurethane, polyisocyanurate, polystyrene (extruded and expanded) and phenolic.

In use, the rigid sheet or board materials form

only part of the structure of a wall, ceiling, floor or roof. Other materials used in the construction are typically masonry, timber and steel for the load bearing component; mineral wool as insulation between the studs of a frame or as insulation between rafters; profiled plastic, steel or timber as protective cladding; and plastics, aluminium, and bitumen, often reinforced with paper or other fibrous materials, as water vapour or moisture control layers. These latter materials are usually of rectangular shape provided in roll form and are often used in conjunction with and adjacent to the aforesaid rigid sheet and board materials. One purpose of these flexible sheet materials is to prevent the passage of moisture in liquid or vapour form from one part of the structure to another, in which case they are generally known as waterproof or damproof membranes. Typical areas of use are in floors to prevent rising damp and in walls or roofs to prevent penetrating damp in wet and windy conditions. So for further understanding of the prior art reference is made to the accompanying drawings in which Figure 1 shows a waterproof or damp proof membrane 10 used in conjunction with a rigid insulation sheet 11 under a cement screed floor 12.

Figure 2 illustrates another purpose of the flexible sheet materials which is to reduce the passage of water vapour from the warm side of a wall 13 or ceiling to the cold side thus avoiding interstitial condensation. In this example the flexible sheet material is generally known as a vapour check membrane. Where the membrane prevents the passage of water vapour, it is generally known as a vapour barrier. As illustrated in Figure 2, a vapour check or barrier membrane 14 is used in conjunction with a rigid plasterboard lining sheet 15, on a timber frame wall 16, with mineral wool 17, between the studs 18.

Figure 3 illustrates a further purpose of the flexible sheet materials which is to allow the passage of water vapour through the cold side of a wall or roof 20 but not the passage of liquid water from the external environment to the internal structure of the wall or roof. The flexible sheet material 21 is generally known as a breather membrane, which is shown in conjunction with a rigid foam insulation sarking sheet 22 on a pitched roof 20 having tiles or slates 23 fixed on tiling battens 24.

Figures 1 to 3 represent three-examples of several methods of construction commonly used, in which a rigid sheet material is used in conjunction with and adjacent to a flexible sheet material. It is common practice for the flexible sheeting to be fixed separately from the rigid sheeting. This enables the water/water vapour properties of the flexible sheeting material to be maintained over the entire area of the wall, floor, ceiling or roof and to be continuous, where necessary, into adjoining walls, floors, ceiling or roofs by overlapping the flexible sheeting at joints or intersections according to manufacturers instructions or accepted practice. Figures 4 and 5 show alternative examples. In Figure 4, an upper vapour barrier membrane 25 is lapped over a lower vapour barrier membrane 26 when fixed horizontally across vertical wooden studs 27 inside an outer brick wall 28. Such overlaps are typically 100 to 150 mm.

Figure 5 shows a horizontal overlap and vertical overlap for a breather membrane 29 laid over a rigid, foam insulation sarking sheet 30 on rafters 31 of a pitched roof 32. Such an arrangement is equally applicable to a wall as in Figure 4.

It is therefore common practice to fix or position the flexible sheeting first complete with overlaps at vertical and/or horizontal joints and then fix or position the rigid sheet material with butt

joints in a second operation over the flexible sheeting or vice versa. It would therefore be beneficial if both sheeting materials could be fixed in one operation. Products are available in which the flexible sheet is permanently bonded to one side of the rigid sheet such as aluminium foil or plastics film bonded to plasterboard or to plywood. Such products are fixed butt-jointed together, which does not allow for an overlap of the flexible sheeting. If the barrier properties of the structure are to be maintained then a secondary operation would be required on the joints. This could involve foil or plastic tapes-or composites thereof-being placed over the joints, or filling the joints with a suitable mastic or other water resistant polymeric material.

Secondary operations would also be required where the rigid sheet material has to be cut to fit the dimensions of that part of the building envelope to which it is being fixed, i. e. floor, roof, ceiling or walls, or has to be cut to fit round a detail or opening in the building envelope such as a chimney, door or window. At these details and at the intersections of the various planar parts of the building envelope e. g. floor with wall, pitched roof at the ridge, pitched roof at the eaves and the verge and roof valleys, it can be necessary to use separate flexible sheeting or a moisture control membrane beyond the edge of the rigid sheet material, in order to maintain the moisture transmission properties or water barrier properties of the building envelope. An example of such an arrangement is in Figure 1, in which a separate waterproof or damp proof membrane 10 would be carried up to and overlapped with the damp proof course 35 of the inner block or brick wall 36, thus extending beyond the rigid insulation sheets 11.

An object of the invention is to overcome the need for such secondary operations.

According to the invention there is provided a laminated sheet or board as a building material, comprising a primary sheet or board, and a secondary sheet of flexible material which is bonded face to face with the primary sheet or board, both the primary sheet or board and the secondary sheet being building materials, wherein at least adjacent one edge of the primary sheet or board, the secondary sheet is bonded to the primary sheet or board using-an adhesive which allows that area of the flexible sheet to be peeled away from the primary sheet without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet.

Preferably the primary sheet or board is formed of rigid or substantially rigid material. In other cases, the primary sheet or board may be at least partially flexible.

The secondary sheet preferably has a water or water vapour control characteristic.

It is also preferred that the secondary sheet is bonded to the primary sheet or board using a pressure sensitive adhesive which allows the flexible sheet to be rebonded to any exposed area of the primary sheet or board which is not cut away, using a light pressure.

The adhesive employed preferably allows partial separation of the secondary sheet by manually peeling back the edge portion of the secondary sheet away from the adjacent area of the primary sheet or board.

In one embodiment, during manufacture, the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board.

In another embodiment, along at least one side edge of the primary sheet or board there is provided a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board. The tongue may be one edge of a strip of rigid material which has water or water vapour control properties.

The invention also provides a method of manufacturing a laminated sheet or board as a building material, comprising bonding a secondary sheet of flexible material face to face with'a primary sheet or board, wherein the method comprises employing an adhesive, at least adjacent one edge of the primary sheet or board, which allows that area of the flexible sheet to be peeled away from the primary sheet or board without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet.

During manufacture the adhesive is preferably applied to the facing surface of one of the secondary sheet or the primary sheet or board, or both.

The adhesive employed may be contained in an aqueous medium, or an organic solvent, or maybe 100% solids.

In one embodiment, the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board.

In another embodiment there is provided along at least one side edge of the primary sheet or board a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board. The tongue may be one edge of a strip of rigid material which has water or water vapour control properties.

By way of example, specific embodiments are described with reference to the accompanying drawings in which : Figure 1 shows a flexible membrane in conjunction with a rigid insulation sheet under a cement screed floor; Figure 2 illustrates another embodiment of a flexible membrane and a lining sheet on a timber frame wall; Figure 3 illustrates a further-embodiment of a flexible sheet and an insulation sarking sheet on a pitched roof; Figure 4 shows a horizontal overlap of two flexible sheets fixed across wooden studs inside an outer brick wall; Figure 5 shows similar horizontal and vertical overlaps of an insulation sarking sheet on rafters of a pitched roof; Figure 6 shows a laminated sheet or board manufactured in accordance with the present invention with a corner of the secondary sheet peeled back; Figure 7 shows the laminated sheet or board of Figure 6 after the primary sheet or board has been cut to size along one edge ; Figures 8 and 9 show roof applications involving an overlap of flexible sheets, employing the laminated sheet or board of Figure 6; Figure 10 shows an embodiment of the present invention in which the laminated sheet or board is manufactured with an overlap of the secondary sheet relative to the primary sheet or board on at least one side edge; and Figure 11 shows an alternative embodiment of the present invention.

With reference to Figure 6, there is shown a laminated sheet or board 49 for use as a building

material which has a rigid or substantially rigid, primary sheet or board 50 measuring a conventional 120 cm x 240 cm, or other rectangular form. Superimposed on the surface of the primary sheet or board 50 is a flexible secondary sheet or membrane 51 by applying a pressure sensitive adhesive 52 over the whole area of that surface of the primary sheet or board or the facing surface of the secondary sheet, or over both those surfaces. Both components of the laminated sheet or board 49 are provided for a building purpose. The secondary sheet may have a water or-water vapour control characteristic and be provided for that purpose.

The adhesive selected is suitable for the surface properties of the two adhering surfaces of the particular primary sheet or board 50 and the secondary sheet 51 involved, whilst permitting the partial peeling back of the flexible secondary sheet 51 away from the primary sheet without fracture of the secondary sheet. Peeling back of the secondary sheet 51 is preferably performed manually. The use of a pressure sensitive adhesive 52 also allows the secondary sheet 51 to be subsequently rebonded to the surface of the primary sheet or board 50 from which it has been peeled back. The selected adhesive may be contained in an aqueous medium, or an organic solvent medium or may be 100% solids.

In use, whilst the secondary sheet 51 is peeled back, the exposed part of the rigid primary sheet is cut to size for the particular use for which the sheet or board is intended, at least along one edge, without loss of the flexible sheet overlap. The secondary sheet 51 is then rebonded to any exposed area of the primary sheet or board 50, using a light manual pressure, leaving an edge portion 53 of the secondary sheet projecting beyond the cut edge 54 of the primary sheet or board, as shown in Figure 7.

Following the cutting of the rigid or substantially rigid primary sheet or board 50, the flexible secondary sheet 51 may also be cut to suit the requirements of the particular application, whilst normally leaving a projecting edge portion 53 of the secondary sheet 51.

The same technique is adapted to suit any of the uses for the laminated sheet or board 49, which are illustrated in Figures 1 to 5 for conventional sheet or board, and an associated flexible sheet material.

Other examples of roof applications employing the laminated sheet or board 49 of the present invention are illustrated in Figures 8 and 9. In each example, the secondary sheet 51 is made larger than the primary sheet or board 50 by cutting the primary sheet or board along at least one edge as in Figure 7. The edge portion 53 of the secondary sheet projecting beyond the or each cut edge 54 is then used to overlap the secondary sheet 51 of the adjacent laminated sheet or board to create the desired barrier control between the two laminated sheets or boards. Figure 8 shows a secondary sheet overlap at gutter level whereas Figure 9 shows a secondary sheet overlap at the ridge of the roof. In the latter case, both laminated sheets or boards 49 are shown having a projecting edge portion of the secondary sheet 51. The adhesive 52 on the undersurface of each projecting edge portion is beneficial in that it provides a degree of bonding of the edge portion to the primary sheet or board of the secondary sheet with which it is in overlapping contact. In each example, there is provided a continuous overlap without fracture of the secondary sheet 51.

If desired the flexible secondary sheet 51 may be peeled back in two or more directions permitting the primary sheet or board 50 to be cut along more than one edge, and may be on all four sides. Normally the

secondary sheet 51 remains projecting beyond each cut edge 53 of the primary sheet 50.

It is also possible that the pressure sensitive adhesive will be used in the edge portions only of the sheet or board, allowing the use of a permanently bonding adhesive, or no adhesive to be applied in the central area of the sheet or board where there would be no need to peel back the secondary sheet 5.

Uses for the laminated sheet or board 49 are not limited to those illustrated in Figures 1,5 and 8 to 9 of the drawings, but can include all uses known within the building industry.

The use of a rigid or substantially rigid primary sheet or board in the above embodiments is advantageous because it assists fixing the laminated sheet or board 49, for example, using nails or screws.

Also, in some cases, e. g. for use on an exterior wall surface or roof, it is advantageous that the secondary sheet is peelable, because it can be peeled back before fixing the primary sheet or board and then rebonded to the primary sheet or board concealing the fixing nails or screws. At the same time, the secondary sheet remains unbroken at the fixing positions thereby further assisting the effectiveness of the secondary sheet.

Figure 10 illustrates a laminated sheet or board 55 which is similar to the sheet or board 49 except that the sheet or board 55 is manufactured with the secondary sheet 51 having an overlap 58 of desired size relative to the primary sheet or board 50 on at least one side edge. In the embodiment illustrated the manufactured overlap 58 is provided on two side edges 56,57 of the primary sheet or board, but it may be provided on only one side edge or on three or four side edges.

The secondary sheet 51 is still peelable relative to the primary sheet or board 50 in the same manner as

described above in relation to the sheet or board 49, but an advantage of the sheet or board 55 is that it can be used as supplied, i. e. with the manufactured overlap 58 on one or more side edges and/or cut to size before being used. If the sheet or board 55 is to be cut, the secondary sheet 51 is peeled back to enable at least the primary sheet or board 50 to be cut to size in the manner described above with reference to the sheet or board 49, and then rebonded without loss of overlap.

In a further example of the present invention shown in Figure 11, the laminated sheet or board 49 has a groove 60 along one, two, three or four edges of the primary sheet or board 50. The groove 60 provides location for a tongue comprising one edge of a thin strip 61 of rigid material, which in this embodiment has water or water vapour control properties, the opposite edge of the strip being received in a groove 60 in the facing edge of the adjacent sheet or board.

The strip 61 thereby forms a bridge between two adjacent sheets or boards 49 as illustrated to further improve moisture movement at the joint therebetween.

The strip 61 can also provide an additional advantage of reducing air movement between the inside of a building and the outside atmosphere. This is of particular benefit when the purpose of the laminated sheets or boards is heat insulation. The strip 61 may be made from thin insulating foam sheet with or without a facing material on one or both surfaces.

Claims

CLAIMS : 1. A laminated sheet or board as a building material comprising a primary sheet or board, and a secondary sheet of flexible material which is bonded face to face with the primary sheet or board, both the primary sheet or board and the secondary sheet being building materials, wherein at least adjacent one edge of the primary sheet or board, the secondary sheet is bonded to the primary sheet or board using-an adhesive which allows that area of the flexible sheet to be peeled away from the primary sheet without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet. 2. A laminated sheet or board as claimed in Claim 1, wherein the primary sheet or board is formed of rigid or substantially rigid material. 3. A laminated sheet or board as claimed in Claim 1 or Claim 2, wherein the secondary sheet has a water or water vapour control characteristic. 4. A laminated sheet or board as claimed in any one of the preceding claims, wherein the secondary sheet is bonded to the primary sheet or board using a pressure sensitive adhesive which allows the flexible sheet to be rebonded to any exposed area of the primary sheet or board which is not cut away, using a light pressure. 5. A laminated sheet or board as claimed in any one of the preceding claims, wherein the adhesive employed allows partial separation of the secondary sheet by manually peeling back the edge portion of the secondary sheet away from the adjacent area of the primary sheet or board. 6. A laminated sheet or board as claimed in any one of the preceding claims, wherein, during manufacture, the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board. 7. A laminated sheet or board as claimed-in any one of the preceding claims, wherein along at least one side edge of the primary sheet or board there is provided a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board. 8. A laminated sheet or board as claimed in Claim 7, wherein the tongue is one edge of a strip of rigid material which has water or water vapour control properties. 9. A method of manufacturing a laminated sheet or board as a building material, comprising bonding a secondary sheet of flexible material face to face with a primary sheet or board, wherein the method comprises employing an adhesive, at least adjacent one edge of the primary sheet or board, which allows that area of the flexible sheet to be peeled away from the primary sheet or board without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet. 10. A method as claimed in Claim 9, wherein the primary sheet or board is formed of rigid or substantially rigid material. 11. A method as claimed in Claim 9 or Claim 10, wherein the secondary sheet is provided for a water or water vapour control purpose. 12. A method as claimed in any one of Claims 9 to 11, wherein the adhesive employed is a pressure sensitive adhesive which allows the flexible sheet to be rebonded to any exposed area of the primary sheet or board which is not cut away, using a light pressure. 13. A method as claimed in any one-of Claims 9 to 12, wherein the adhesive employed allows partial separation of the secondary sheet by manually peeling back the edge portion of the secondary sheet away from the adjacent area of the primary sheet or board. 14. A method as claimed in any one of Claims 9 to 13, wherein the adhesive is applied to the facing surface of one of the secondary sheet or the primary sheet or board, or to both. 15. A method as claimed in any one of Claims 9 to 14, wherein the adhesive employed is contained in an aqueous medium, or an organic solvent. 16. A method as claimed in any one of Claims 9 to 15, wherein the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board. 17. A method as claimed in any one of Claims 9 to 16 wherein there is provided along at least one side edge of the primary sheet or board a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board. 18. A method as claimed in Claim 17, wherein the tongue is one edge of a strip of rigid material which has water or water vapour control properties. 19. A laminated sheet or board as a building material substantially as hereinbefore described with reference to and as shown in Figures 6 to 11 of the accompanying drawings. 20. A method of manufacturing a laminated sheet or board as a building material substantially as hereinbefore described with reference to Figures 6 to 11 of the accompanying drawings. Amendments to the claims have been filed as follows

1. A laminated sheet or board as a building material comprising a primary sheet or board, and a secondary sheet of flexible material which is bonded face to face with the primary sheet or board, both the primary sheet or board and the secondary sheet being building materials, wherein at least adjacent one edge of the primary sheet or board, the secondary sheet is bonded to the primary sheet or board using an adhesive which allows that area of the flexible sheet to be peeled away from the primary sheet without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet.

2. A laminated sheet or board as claimed in Claim 1, wherein the primary sheet or board is formed of rigid or substantially rigid material.

3. A laminated sheet or board as claimed in Claim 1 or Claim 2, wherein the secondary sheet has a water or water vapour control characteristic.

4. A laminated sheet or board as claimed in any one of the preceding claims, wherein the secondary sheet is bonded to the primary sheet or board using a pressure sensitive adhesive which allows the flexible sheet to be rebonded to any exposed area of the primary sheet or board which is not cut away, using a light pressure.

5. A laminated sheet or board as claimed in any one of the preceding claims, wherein the adhesive employed allows partial separation of the secondary sheet by

manually peeling back the edge portion of the secondary sheet away from the adjacent area of the primary sheet or board.

6. A laminated sheet or board as claimed in any one of the preceding claims, wherein the adhesive employed is contained in an aqueous medium or an organic solvent medium.

7. A laminated sheet or board as claimed in any one of Claims 1 to 5, wherein the adhesive employed is 100% solids.

8. A laminated sheet or board as claimed in any one of the preceding claims, wherein, during manufacture, the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board.

9. A laminated sheet or board as claimed in any one of the preceding claims, wherein along at least one side edge of the primary sheet or board there is provided a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board.

10. A laminated sheet or board as claimed in Claim 9, wherein the tongue is one edge of a strip of rigid material which has water or water vapour control properties.

11. A method of manufacturing a laminated sheet or board as a building material, comprising bonding a secondary sheet of flexible material face to face with a primary sheet or board, wherein the method comprises employing an adhesive, at least adjacent one edge of the primary sheet or board, which allows that area of

the flexible sheet to be peeled away from the primary sheet or board without fracture of the secondary sheet, and which allows the exposed part of the primary sheet or board to be cut through without loss of the continuous overlap with the secondary sheet.

12. A method as claimed in Claim 11, wherein the primary sheet or board is formed of rigid or substantially rigid material.

13. A method as claimed in Claim 11 or Claim 12, wherein the secondary sheet is provided for a water or water vapour control purpose.

14. A method as claimed in any one of Claims 11 to 13, wherein the adhesive employed is a pressure sensitive adhesive which allows the flexible sheet to be rebonded to any exposed area of the primary sheet or board which is not cut away, using a light pressure.

15. A method as claimed in any one of Claims 11 to 14, wherein the adhesive employed allows partial separation of the secondary sheet by manually peeling back the edge portion of the secondary sheet away from the adjacent area of the primary sheet or board.

16. A method as claimed in any one of Claims 11 to 15, wherein the adhesive is applied to the facing surface of one of the secondary sheet or the primary sheet or board, or to both.

17. A method as claimed in any one of Claims 11 to 16, wherein the adhesive employed is contained in an aqueous medium, or an organic solvent medium.

18. A method as claimed in any one of Claims 11 to 16, wherein the adhesive employed is 100% solids.

19. A method as claimed in any one of Claims 11 to 18, wherein the secondary sheet is bonded to the primary sheet or board with an overlap of the secondary sheet on at least one side edge of the primary sheet or board.

20. A method as claimed in any one of Claims 11 to 19, wherein there is provided along at least one side edge of the primary sheet or board a groove for reception of a tongue as a joint, in use, with the primary sheet or board of an adjacent laminated sheet or board.

21. A method as claimed in Claim 20, wherein the tongue is one edge of a strip of rigid material which has water or water vapour control properties.

22. A laminated sheet or board as a building material substantially as hereinbefore described with reference to and as shown in Figures 6 to 11 of the accompanying drawings.

23. A method of manufacturing a laminated sheet or board as a building material substantially as hereinbefore described with reference to Figures 6 to 11 of the accompanying drawings.