GB2393456A

GB2393456A - A breathable wall sheathing panel

Info

Publication number: GB2393456A
Application number: GB0222349A
Authority: GB
Inventors: Jean Richardson
Original assignee: TRADE FABRICATION SYSTEMS Ltd
Current assignee: TRADE FABRICATION SYSTEMS Ltd
Priority date: 2002-09-26
Filing date: 2002-09-26
Publication date: 2004-03-31
Anticipated expiration: 2022-09-26
Also published as: GB2393456B; GB0222349D0

Abstract

A wall panel comprises a sheathing board 2 to which is laminated a breathable membrane 4, the membrane being bonded to the sheathing board by a discontinuous layer of adhesive (5, fig 2). The adhesive (5) may be a hot melt adhesive applied to either the sheathing panel or the membrane by a plurality of nozzles. The wall panel may also include a thermally insulating layer 3 and a plurality of timber studs 1. A method is disclosed wherein the hot melt glue may be applied by a spraying system in a predetermined pattern. Preferably, the membrane permits moisture to pass in one direction only. The areas of the wall panel (6, fig 2) between the adhesive (5) are preferably breathable.

Description

A WALL PANEL

The present invention relates to a wall panel for a timber frame construction such as a building and, more particularly, to a breathable wall sheathing panel.

Buildings constructed with a timber frame generally comprise a composite wall supported by a base plate, a top plate and vertical timber studs. A typical wall panel for such an application comprises an inner layer of plasterboard, an intermediate layer of insulation material for reduction of heat losses and an outer layer of sheathing material such as plywood or oriented strand board that provides the strength and rigidity. Such sheathing materials are generally covered by a breathable membrane to protect them against the penetration of moisture from the external environment particularly during construction of the building whilst allowing water vapour (from for example interstitial condensation) to pass from the inside to the outside. The membrane is supplied on a roll to the construction site or to the factory (where the wall panels are assembled) where it is applied to the exterior of the sheathing panels by unrolling and fixing it with staples and nails that pass through the panels to the studs. This is both time consuming and costly. In a factory environment this adds an additional production stage. Where the membrane is fitted on site there is the need for stock to be transported to the site and managed whilst it is there. The membranes are often damaged during transportation or fitting. Moreover, a significant volume of membrane material is disposed as waste in the form of off-cuts or leftover material on the roll.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages. According to a first aspect of the present invention there is provided a wall panel comprising a sheathing board to which is laminated a breather membrane, the membrane being bonded to the sheathing board by a discontinuous layer of adhesive.

The discontinuities (i.e. areas where the adhesive is not present) allow the membrane to remain breathable whilst not compromising the security of the fixing of the membrane to the sheathing board.

The adhesive is preferably applied to the sheathing panel or the membrane in a predetermined pattern that comprises areas of adhesive interspersed with areas clear of

adhesive. Example patterns include a spider's web configuration, hatching, cries-cross or dotting.

The adhesive is preferably a hot melt adhesive that is applied using a plurality of nozzles.

The wall panel preferably further comprises a thermally insulating layer and a plurality of timber studs.

According to a second aspect of the present invention there is provided a method of constructing a laminated wall panel comprising the steps of bonding a breather membrane to a sheathing panel by applying a discontinuous layer of adhesive to said membrane or said sheathing panel and juxtaposing one on the other.

A breather membrane will be recognised by those in the art as a membrane manufactured from a material that allows moisture to pass in one direction but not in the other. In particular it will allow condensation and vapour to pass in one direction out of the sheathing panel but prevent rainwater to pass into the panel.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of part of a wall structure including a wall panel of the present invention; Figure 2 is a sectioned view through a wall panel of the present invention; and Figures 2a), b) and c) are plan views of a breather membrane coated with an adhesive in different patterns in accordance with the present invention.

Figure I of the drawings shows a timber-framed wall structure for a building fitted with a wall panel of the present invention. Parallel vertical timber studs 1 are spaced at regular intervals and a plurality of sheathing panels 2 are secured thereto on the exterior side of the building. The sheathing panels 2 are typically manufactured from oriented strand board, Sterling Board, plywood or other similar wood. An example of such a product is sold under the trade mark Smartply by Louisiana-

Pacific Corporation.

The region between adjacent studs I and behind the sheathing panels 2 can be filled with a thermally insulating material layer 3. On the interior side of the building the wall structure may be lined with plasterboard or the like (not shown). Some or all

of the components of this structure may be supplied on site as a prefabricated composite panel.

The exterior of the sheathing panel 2 is laminated with a breather membrane 4.

Such membranes are well known in the art for providing resistance to the ingress of water and moisture whilst allowing moisture to egress from the building structure. A membrane of this kind is sold under the trade mark Tyvek.

In the present invention the breather membrane is applied to the sheathing panel in a particular manner that provides many advantages.

After the membranes 4 have been cut to size during the manufacturing process they are conveyed to an adhesive spraying station where hot melt adhesive is sprayed on to them in a predetermined pattern that provides for a application of a discontinuous layer of hot melt adhesive 5 (see figures 2 and 3). A sheathing panel 2 of the same dimensions is then laid over the adhesive and bonded to the membrane 4.

The membrane 4 adheres to the panel 2 where the adhesive is present but does not adhere at the discontinuities 6. This method provides for secure fixing of the membrane to the panel but does not compromise the breathability of the membrane as it is able to breathe through the areas where the hot melt adhesive is not present.

The hot melt adhesive is heated by a DYNAMELT _ unit and applied by a DYNAFIBER _ applicator. The hot melt adhesive is of the kind that is commonly used in the packaging of foodstuffs and for gluing book spines. The supply unit comprises a plurality of hoppers that are configured to melt the adhesive on demand and supply it in a controlled volumetric dose to the applicator. The applicator comprises a plurality of nozzles fixed to a carriage that is disposed over the panel to be treated. The adhesive is pumped to the nozzles where it egresses in the form of a spray and applies it in a predetermined pattern with precise control of the adhesive fibre size. Example patterns are illustrated in figures 3a), b) and c). In figure 3a the adhesive is applied in a spider's web configuration, in figure 3b in a cries-cross pattern and in figure 3c as a plurality of spaced dots. Other patterns may be used to achieve the same effect.

The application of the membrane to the panel in this fashion provides for a sheathing panel that is pre-laminated with the breather membrane and thus eliminates

the need for separate application of the membrane as part of the construction process whether in a factory environment, where wall panels are prefabricated, or on site. This much simplifies the construction process and reduces damage and waste.

It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims. For example, the hot melt adhesive may be applied to the sheathing panel rather than the membrane prior to lamination.

Claims

1. A wall panel comprising a sheathing board to which is laminated a breather membrane, the membrane being bonded to the sheathing board by a discontinuous layer of adhesive.

2. A wall panel according to claim 1, wherein the adhesive is applied to the sheathing panel or the membrane in a predetermined pattern comprising areas of adhesive interspersed with areas clear of adhesive.

3. A wall panel according to claim 1 or 2, wherein the adhesive is a hot melt adhesive that is applied using a plurality of nozzles.

4. A wall panel according to any preceding claim, further comprising a thermally insulating layer and a plurality of timber studs.

5. A method of constructing a laminated wall panel comprising the steps of bonding a breather membrane to a sheathing panel by applying a discontinuous layer of adhesive to said membrane or said sheathing panel and juxtaposing one on the other.

6. A method according to claim 5, wherein the adhesive is applied by a hot melt spraying system.

7. A method according to claim 6, wherein the adhesive is applied using a predetermined pattern.

8. A wall panel substantially as hereinbefore described with reference to the accompanying drawings.

9. A method of constructing a laminated wall panel substantially as hereinbefore described with reference to the accompanying drawings.