GB2610638A

GB2610638A - An assembly and a method for providing insulation below the floor of a building

Info

Publication number: GB2610638A
Application number: GB2113070.3A
Authority: GB
Inventors: Wesley Collings Stephen
Original assignee: Devana Properties Ltd
Current assignee: Devana Properties Ltd
Priority date: 2021-09-14
Filing date: 2021-09-14
Publication date: 2023-03-15
Also published as: GB202113070D0

Abstract

An assembly to provide insulation below a suspended floor of a building. The assembly includes a set of pairs of hangers (24), wherein each hanger includes an upwardly extending body portion and a support portion, the body portion has a rear surface for engagement with a supporting structure, the rear surface lies in a body portion plane, and the support portion extends laterally below the floor away from the body portion plane on the opposite side of the body portion to its rear surface. Each of a set of elongate supports (26) is carried by one of a respective pair of hangers, and the elongate supports are arranged so as to extend laterally below the floor between the body portion planes of the respective hangers. Insulating material is provided in the space defined between the set of elongate supports and the floor.

Description

Title: An Assembly And A Method For Providing Insulation Below The Floor Of A Building

Field of the invention

The present invention relates to installation of insulation below a suspended floor of a building. More particularly, it refers to an assembly and method suitable for providing such insulation in a retro-fitting procedure.

Background to the invention

In Britain, millions of residential properties were built in the 19th century and the first part of the 20th century with suspended timber ground floors. The void under the floor is vented by air bricks in the external walls to avoid damp rising from the ground into the floor and rooms. However, this does mean that the floors can be remarkably cold.

The void is at external temperatures and draughty. Gaps between the floorboards and around the edges of rooms under the skirting board allow this cold air to flow freely into the room. During cold weather, this makes it difficult to efficiently maintain a comfortable temperature in the room.

Given the increasing need to enhance the energy efficiency of older homes in the face of climate change, it is desirable to improve the insulation of such homes as much as possible.

Summary of the invention

The present invention provides an assembly arranged to provide insulation below a suspended floor of a building, the assembly comprising: a set of pairs of hangers, wherein each hanger includes an upwardly extending $0 body portion and a support portion, the body portion has a rear surface for engagement with a supporting structure, the rear surface lies in a body portion plane, and the support portion extends laterally below the floor away from the body portion plane on the opposite side of the body portion to its rear surface; a set of elongate supports, wherein each end of each elongate support is carried by one of a respective pair of hangers, and the elongate supports are arranged so as to extend laterally below the floor between the body portion planes of the respective hangers, and be vertically spaced from the floor; and insulating material provided in the space defined between the set of elongate supports and the floor.

The assembly may be installed from above the suspended floor, which is beneficial as this may in some cases be the only way to access the void below the floor. The installation may be carried out by removing only a few of the boards. This avoids the need to remove the entire floor and possibly also the skirting boards around the perimeter of the floor which might otherwise require redecoration of the room once the floor has been reinstated.

The assembly may support insulating material which extends beneath the joists. The insulating material may also extend between the joists. The insulating material may substantially fill the space defined between the set of elongate supports and the floor. The insulating material may be rigid Alternatively, it may be non-rigid. For example, it may be a fibrous material.

As the set of elongate supports is vertically spaced from the undersides of the joists, it defines a space between the set and the floor structure to be filled with insulating material. As a result, the space to be filled with the insulating material may extend continuously beneath the joists from one side of the room to the other. An unbroken layer of insulating material may be provided in the space over the floor area of the room. Providing a layer of insulating material which extends continuously below the joists, significantly improves the thermal resistance provided by the insulation, compared to only providing insulating material between the joists.

3o Since the assembly is suspended below the floor, the set of elongate supports can be spaced from the ground below to still allow circulation of air below the insulated floor structure in accordance with building regulations.

The elongate supports are preferably arranged to extend in a direction perpendicular to the body portion planes of the respective hangers.

The insulating material preferably comprises cellulose fibre and/or mineral wool fibre. This material may provide good insulation and also minimise penetration of cold air flow through to the underside of the floor. It may be preferable to use mineral wool fibre in installations where the insulation may be exposed to damp, due to its moisture resistance.

io The insulating material may be directly supported by the elongate supports alone. In some implementations, the assembly may include a support layer carried by the set of supports to support the insulating material. The support layer may support and/or contain the insulating material in the space between the underside of the floor and the set of elongate supports.

The assembly preferably includes a support layer carried by the set of supports to support the insulating material. The support layer may be formed of flexible, semirigid or rigid material. It may be formed from vapour permeable sheet material, such as a fabric or board material. A flexible material may more readily be inserted into the space below the floor where access may be restricted if only selected floorboards have been removed. At least one edge of the support layer may be fastened in position using an adhesive.

In some implementations, the assembly may include spacer members which extend vertically between sleeper walls that are adjacent to external walls of the building and floorboards of the suspended floor, wherein the spacer members are spaced laterally from the external walls so as to define an air gap between the spacer members and the external walls Each spacer member extends over an opening defined by a sleeper wall, and floorboards and joists of the suspended floor, and may be a friction fit in the 3o corresponding opening. The spacer members may comprise rigid insulating material.

The spacer members may act to contain the insulating material within a volume which is spaced from an adjacent external wall of the building to allow air to flow to and circulate around a space between the insulation and the ground beneath In further examples, the assembly may include supporting spacers which extend between sleeper walls that are adjacent to an external wall of the building and the external wall, wherein the supporting spacers extend laterally from an upper surface of the respective sleeper wall to the external wall, and include a spacer portion which is spaced laterally from the external wall so as to define an air gap between the spacer io portion and the external wall. Such a configuration may be desirable where a sleeper wall is spaced by a significant distance (for example, more than around 35mm) from the adjacent external wall. The supporting spacers may enable insulating material to still be provided beneath the floor which extends laterally almost to the external wall, but is spaced therefrom to provide the air gap and thereby facilitate circulation of air beneath the insulation In a preferred example, the supporting spacers carry rigid material which extends between a sleeper wall and floorboards and joists of the floor, and is spaced laterally from the external wall of the building. The rigid material may comprise rigid insulating material. The supporting spacers, in combination with the rigid material, may contain the insulating material within a volume which is spaced from an adjacent external wall of the building to allow air to flow to and circulate around a space between the insulation and the ground beneath.

The present invention further provides a method of installing an assembly arranged to provide insulation below a suspended floor of a building, the method comprising the steps of.

removing at least one floorboard to provide access to the space below the suspended floor; mounting pairs of hangers below the floor; coupling each of a set of elongate supports to respective pairs of hangers so that the supports extend laterally below the floor and are vertically spaced from the floor; and inserting insulating material into the space defined between the set of elongate supports and the floor.

In carrying out the method, the components of the assembly may all be inserted into a void below a suspended floor via the opening(s) created by removing at least one floorboard. The installation may be carried out by only removing selected floorboards, thereby reducing disruption of the existing floor structure and reducing the time taken to carry out the installation.

io Each hanger may include an upwardly extending body portion, wherein the body portion has a rear surface for engagement with a support structure, the rear surface lies in a body portion plane, each end of each elongate support is carried by one of a respective pair of hangers, and the elongate supports are arranged so as to extend between the body portion planes of the respective hangers.

The installation method may include a step of laying a support layer over the set of elongate supports prior to the step of inserting the insulating material The support layer may be formed of flexible material.

In some preferred implementations, the step of inserting insulating material comprises blowing insulating material into the space defined between the set of elongate supports and the floor. This may allow the insulating material to be packed into the space whilst only having limited access to the space.

Each hanger may include an engagement portion for engaging with an upwardly facing surface of a supporting structure, with the engagement portion extending laterally away from the body portion plane on the same side of the body portion as its rear surface The supporting structure may be an existing sleeper wall which supports the joists of the suspended floor.

Preferably, the elongate supports of the first subset are substantially C-shaped in transverse cross-section. Each of the supports may consist of a central planar portion which extends lengthways along the support, and a pair of flanges which extend lengthways along the support and substantially perpendicularly to the plane of the central planar portion, from each edge thereof The present invention also provides a kit of parts for forming an assembly providing insulation below a suspended floor as described herein.

Brief description of the drawings

A known suspended floor construction and examples of the present invention will io now be described with reference to the accompanying schematic drawings, wherein: Figure 1 is a plan view of a suspended timber ground floor of a building; Figure 2 is a partial view of the floor shown in Figure 1, with the floorboards and wall-plates removed; Figure 3 shows the view of Figure 2 with the wall-plates in position; Figure 4 shows the view of Figure 3 with joists installed over the wall-plates; Figure 5 is a plan view of a suspended timber ground floor of a building with selected floorboards removed, Figure 6 is a plan view of the room shown in Figure 5 with all of the floorboards removed to show the wall-plates carrying hangers and elongate supports from an assembly according to an example of the present disclosure; Figure 7 is a cross-sectional view of an assembly according to an example of the present disclosure prior to insertion of insulating material, Figure 8 shows the view of Figure 7 following the insertion of insulating material, Figures 9 to 11 are front sectional, side sectional and plan views, respectively, of a hanger according to an example of the present disclosure; Figures 12 and 13 are partial perspective and end views, respectively, of an elongate support according to an example of the present disclosure, Figure 14 is a front cross-sectional view of a hanger and elongate support carried by 3o the hanger; Figure 15 is a front view of a hanger and elongate support during location of the elongate support onto the hanger, Figure 16 is an enlarged view of part of the assembly shown in Figure 7; Figure 17 is a partial plan view of the hanger and elongate support shown in Figure 16; Figure 18 is a front view of part of an assembly according to an example of the present disclosure where it meet an internal wall of a building; Figure 19 shows the view of Figure 18 following the insertion of insulating material; Figure 20 is a cross-sectional side view of a further assembly according to an example of the present disclosure prior to insertion of insulating material; Figure 21 shows the view of Figure 20 following the insertion of insulating material; Figure 22 is a cross-sectional view of another assembly according to an example of io the present disclosure prior to insertion of insulating material; Figure 23 shows a view of Figure 22 following the insertion of insulating material; Figures 24 to 26 show front, side and plan views, respectively, of a supporting spacer; and Figures 27 and 28 are partial front and plan views, respectively, of the example shown in Figure 22

Detailed description

Figure 1 shows a plan view of a suspended timber floor in one room of a building.

The building has external walls 2 and 4 with a width corresponding to that of two bricks. The dimensions of the floor are defined by two internal walls 6 and 8 which are a single brick wide. The floor 10 is formed from a plurality of parallel floorboards 12, each of which extends from one side of the room to the other.

Figures 2 to 4 show the construction of the building below the floorboards. As shown in Figure 2, sleeper walls 14, 16 of brick construction are provided below the floorboards in a direction parallel to the length of the floorboards. An end sleeper wall 14 is adjacent to external wall 2 and intermediate sleeper wall 16 is parallel to sleeper wall 14 and located partway across the room. As depicted in Figure 3, end 3o and intermediate wall-plates 18 and 20 are bedded on sleeper walls 14 and 16, respectively. Each wall-plate may be formed from a length of timber having a 4x2 inch cross-section. Figure 4 shows a plurality of joists 22 fixed onto the tops of the wall-plates and extending perpendicular thereto Each joist may have a 4x2 inch cross-section, for example Figure 5 shows a typical room with six boards lifted to enable installation of an assembly according to the present disclosure. The room includes a solid fireplace 15. In this example, only six boards need to be removed to provide sufficient access to the wall-plates 18, 20 beneath the floor. The wall-plates are visible in the view of Figure 6, in which all of the floorboards have been removed for the purposes of illustration. The location of the joists 22 is shown in Figure 6 using dashed lines The view of Figure 6 also includes hangers 24 and elongate supports 26 of an assembly according to an example of the present disclosure which are installed on the wall-plates. Each elongate support is carried at each end by one of a respective pair of hangers. Each hanger is in turn carried by a wall-plate. The elongate supports are arranged perpendicular to the wall-plates and are evenly spaced along the length of each wall-plate.

An enlarged cross-sectional side view of part of an assembly according to an example of the present disclosure is shown in Figure 7. A flexible membrane 28 is included which extends from one side of the room to the other. Each end 30 of the membrane is fastened to a joist 22 and rests on the elongate supports 26 between the joists. The membrane is fastened onto an inwardly facing surface 32 of a joist at each end. In this way, an air gap is provided between the membrane and the external wall 2, to allow circulation of air between the membrane and the external wall, and beneath the membrane, above the underlying ground 34.

The hangers 24 may be located on a wall-plate 18 at intervals of around 400mm. This dimension is not critical and is selected to control the degree to which the membrane sags between each elongate support. It may also be varied to fit between existing joist locations, as can be seen in Figure 6. The use of a flexible membrane, rather than rigid boards of a given size, provides greater flexibility in the location of the hangers and elongate supports.

Figure 8 shows a similar view of Figure 7, following insertion of insulating material 40 between the membrane 28 and the floor 10. The insulating material forms a homogenous layer which extends under the joists, to reduce the thermal bridging of the joists themselves, as well as filling the space between the joists. A fibrous insulation material may be used for example, such as cellulose-fibre or mineral wool fibre insulation. The insulating material may be blown into the space via a tube or hose inserted through the openings in the floor created by removal of the selected floorboards. This approach provides a relatively airtight layer of insulation, filling the available space relatively quickly. The insulating material may form a continuous io layer extending over the intermediate wall-plates and below the joists.

Figure 11 shows a plan view of a hanger 24. A cross-sectional front view along line B-B marked on Figure 11 is shown in Figure 9. A cross-sectional side view along line A-A marked in Figure 11 is shown in Figure 10.

The hanger 24 has a planar body portion 42. The body portion includes a rear surface 44. A planar engagement portion 46 of the hanger extends from one end of the body portion, on the same side as the rear surface 44, in a direction perpendicular to the plane of the body portion. A planar support portion 48 extends from the opposite end of the body portion to the engagement portion 46, in a direction perpendicular to the plane of the body portion, on the opposite side to the engagement portion.

The hanger 24 may be shaped to define one or two ribs 50 which extends around the intersection between the body and support portions and partway along the body and support portions. The or each rib acts to increase the resistance of the hanger to bending at this intersection, allowing the use of thinner sheet material for a given rigidity and thereby reducing material costs.

In an alternative example of the hanger 24, the raised ribs 50 may be omitted to $0 simplify fabrication of the hanger. It may then be necessary to form the hanger from thicker sheet material in order to provide similar rigidity at the junction between the portions 42 and 48 as in the configuration including ribs. For example, sheet steel material having a thickness of 3mm may be appropriate if no ribs are present, whereas the thickness may be reduced to 1 5mm if ribs are included.

A pair of holes 52 is defined in the engagement portion to facilitate fastening of the hanger to a supporting structure. A further hole 54 is formed in the support portion and its purpose will be described in more detail below.

Figures 12 and 13 show a perspective view of an end portion, and an end view, of an elongate support 26, respectively. The support comprises a planar, central portion 60.

io Planar side portions 62 and 64 extend to the same side of the central portion, from each longitudinally extending edge of the central portion, in a direction perpendicular to the plane of the central portion. A narrow flange 66, 68 extends inwardly from the distal edge of each side portion, in a direction parallel to the plane of the central portion An elongate support 26 is shown resting on the support portion 48 of a hanger 24 in Figure 14. Each elongate support may be carried by the support portions of the respective hangers. Preferably, the dimensions of these components are selected such that the width, w, of the support portion 48 is slightly greater than the transverse spacing, s, between the opposed flanges 66 and 68 of the elongate support 26. The width, w, of the support portion is in turn slightly less than the transverse distance, d, between the side portions 62, 64 of the elongate support. Accordingly, it is possible to locate the support portion of the hanger within the volume of the elongate support by initially rotating the elongate support about its longitudinal axis as shown in Figure 15, and then rotating the elongate support in the opposite direction so that both edges of the support portion are within the volume of the elongate support. Then, with the central portion 60 of the elongate support parallel to and resting on the planar support portion 48, the support portion is loosely captive within the elongate support due to the small difference between the width, w, of the support portion and the width, d, of io the elongate support.

Figure 16 shows an enlarged view of a left-hand portion of Figure 7. Figure 17 shows a plan view of the hanger 24 of Figure 16. A fastener 70 (in the form of a fir tree plug, for example) has been inserted through the hole 54 formed in the support portion 48 of the hanger 24. The fastener holds the elongate support 26 in place against the support portion. The fastener also fixes the membrane 28 to the hanger and can be used to hold the membrane in a tensioned state between the hanger and other hangers.

Arrow V in Figure 16 illustrates the flow of air from an air brick in the external wall 2 to the space below the assembly.

A sequence of steps in a process to install an assembly according to an example of the lo present disclosure will now be described. The assembly is suitable for use in a retrofitting procedure, requiring removal of only a small number of the floorboards as an initial step, as illustrated by Figure 5, Hangers 24 are then passed through the openings in the floor and fastened to the wall plates at the required locations, using screws for example. The elongate supports 26 are cut to the desired length and then located on the respective hangers. Each elongate support should be long enough to bear adequately on the respective hangers without covering the holes 54 used by the fasteners 70. A membrane, such as a scrim fabric for example, is then spread over the elongate supports. One side is taken up a sleeper wall 14 and stapled to the wall-plate 18 on top of the sleeper wall. Fasteners 70 are then inserted to hold an edge of the membrane. The membrane is then stretched taut across the elongate supports and fasteners then pushed into the opposite set of hangers. The opposite side the membrane is then taken up the second sleeper wall and stapled to its wall-plate.

With regard to the remaining two sides of the membrane, where wall 2 is an external wall, the side of the membrane is then stapled to an inwardly facing surface 72 of a respective joist, as can be seen in Figure 16 This maintains a flow path V from outside the building to below the insulation. Where wall 2 is an internal dividing wall, the membrane is lapped up the wall enabling the insulation to extend up to the wall without an airgap between the membrane and the wall. This is illustrated in $0 Figures 18 and 19. The membrane may be self-supporting against the wall in this configuration if it is sufficiently stiff and the nearest bearer is sufficiently close to the wall. Alternatively, an adhesive may be used to fasten the membrane to the surface of the wall, for example.

Insulating material may then be inserted into the space defined between the flexible membrane arid the underside of the floorboards and may substantially fill the space A fibrous insulation material may be used for example, such as cellulose-fibre or mineral wool fibre insulation. The insulating material may be blown into the space via a tube or hose inserted through the openings in the floor created by removal of the selected floorboards. This approach provides a relatively airtight layer of insulation. The insulating material may form a continuous layer extending over the intermediate wall-plates and below the joists In preferred examples, an airgap is provided between the insulating material of the assembly and external walls of the building. This is to reduce the risk of moisture build-up below the suspended floor, which might otherwise lead to mould and decay building materials. Figures 20 and 21 illustrate a way to achieve such an airgap in a construction where a sleeper wall is relatively close to an adjacent external wall.

Figures 22 to 28 show an alternative approach suitable for a construction where a sleeper wall is a greater distance from an adjacent external wall.

In the example of Figures 20 and 21, a spacer member in the form of a length of rigid, breathable insulation material 80 (such as Acoustic Rockfloor material from Rockwool Limited) is inserted between a wall-plate 18 and the underside of the floorboards 12. The spacer member may be sized to be a friction fit in the corresponding aperture. A holder component 82 is provided to retain the insulation material 80 at a predetermined spacing (preferably around 20mm) from the external wall. One end of the holder component rests against the external wall whilst its other end is fastened to the insulation material. For example, the holder component may pass through the insulation material and include retainers 84 which are held in fixed positions on the holder component, in engagement with opposite sides of the insulating material. The retainers may be disc-shaped for example. The configuration 3o of Figure 20 is shown in Figure 21 following insertion of blown insulation material 40 beneath the floorboards.

The configuration of Figures 22 to 28 uses supporting spacers or straps 90 to bridge the horizontal distance between a sleeper wall 14 and an adjacent external wall 2. The configuration of Figure 22 is shown in Figure 23 following insertion of blown insulation material 40 beneath the floorboards.

A suitable supporting spacer is shown in Figures 24 to 26. It is formed from a strip of rigid material which is bent to form a base portion 92, a spacer portion 96 and a wall engaging portion 98. The spacer portion is perpendicular to the base portion. The wall engaging portion extends from the opposite end of the spacer portion to the base portion, in the opposite direction to the base portion. A hole 100 is formed in the base portion to enable it to be fastened to an upper surface of a wall-plate, using a screw for example. Further holes 102 and 104 are formed in the base portion and the spacer portion, respectively, to enable two lengths 106 and 108 of rigid insulation material (such as Acoustic Rockfloor material from Rockwool Limited) to be fastened to the supporting spacer as shown in Figure 22. This may be achieved using fasteners in the form of fir tree plugs, for example.

The base portion 92 of the supporting spacer 90 may be made sufficiently long to accommodate a predetermined range of spacings between a sleeper wall and the adjacent external wall.

The rigid insulation material may be arranged to close off the opening formed between the sleeper wall and the underside of the floorboards whilst defining an air gap 110 between the insulation and the external wall The width of the airgap may be defined by the length of the wall engaging portion 98 which dictates how far the spacer portion is located from the external wall.

The sub-assembly comprising the supporting spacers 90 and the lengths of rigid insulation material 106 and 108 is preferably formed by passing its components into 3o the space beneath the floor and then assembling the parts before locating the subassembly in the required position. This avoids having to remove further floorboards in order to pass a completed sub-assembly through the floor.

The hangers, elongate supports and/or supporting spacers of the assembly may be formed of galvanised steel, for example.

It will be appreciated that references herein to perpendicular or parallel relative orientations and the like are to be interpreted as defining perpendicular or parallel relationships between components within practical tolerances Such a tolerance may be +/-5° for example.

Claims

Claims I. An assembly arranged to provide insulation below a suspended floor of a building, the assembly comprising: a set of pairs of hangers, wherein each hanger includes an upwardly extending body portion and a support portion, the body portion has a rear surface for engagement with a supporting structure, the rear surface lies in a body portion plane, and the support portion extends laterally below the floor away from the body portion plane on the opposite side of the body portion to its rear surface; to a set of elongate supports, wherein each end of each elongate support is carried by one of a respective pair of hangers, and the elongate supports are arranged so as to extend laterally below the floor between the body portion planes of the respective hangers, and be vertically spaced from the floor; and insulating material provided in the space defined between the set of elongate supports and the floor.
2. An assembly of claim 1 including a support layer carried by the set of supports to support the insulating material.
3. An assembly of claim 2, wherein the support layer is formed of flexible material.
4. An assembly of any preceding claim including spacer members which extend vertically between sleeper walls that are adjacent to external walls of the building and floorboards of the suspended floor, wherein the spacer members are spaced laterally from the external walls so as to define an air gap between the spacer members and the external walls.
5. An assembly of claim 4, wherein each spacer member extends over an opening 3o defined by a sleeper wall, and floorboards and joists of the suspended floor.
6. An assembly of claim 4 or claim 5, wherein the spacer members comprise rigid insulating material.
7 An assembly of any preceding claim including supporting spacers which extend between sleeper walls that are adjacent to an external wall of the building and the external wall, wherein the supporting spacers extend laterally from an upper surface of the respective sleeper wall to the external wall, and include a spacer portion which is spaced laterally from the external wall so as to define an air gap between the spacer portion and the external wall.
8. An assembly of claim 7, wherein the supporting spacers carry rigid material which extends between a sleeper wall and floorboards and joists of the floor, and is spaced laterally from the external wall of the building.
9. An assembly of claim 8, wherein the rigid material comprises rigid insulating material.
10. A method of installing an assembly arranged to provide insulation below a suspended floor of a building, the method comprising the steps of: removing at least one floorboard to provide access to the space below the suspended floor; mounting pairs of hangers below the floor; coupling each of a set of elongate supports to respective pairs of hangers so that the supports extend laterally below the floor and are vertically spaced from the floor; and inserting insulating material into the space defined between the set of elongate supports and the floor.
11. A method of claim 10, wherein each hanger includes an upwardly extending body portion, the body portion has a rear surface for engagement with a support structure, the rear surface lies in a body portion plane, each end of each elongate $0 support is carried by one of a respective pair of hangers, and the elongate supports are arranged so as to extend between the body portion planes of the respective hangers.
12 A method of claim 10 or claim 11, including a step of laying a support layer over the set of elongate supports prior to the step of inserting the insulating material.
13. A method of any of claims 10 to 12, wherein the step of inserting insulating material comprises blowing insulating material into the space defined between the set of elongate supports and the floor.
14. An assembly of any of claims 1 to 9 or a method of any of claims 10 to 13, wherein each hanger includes an engagement portion for engaging with an upwardly io facing surface of a supporting structure, and the engagement portion extends laterally away from the body portion plane on the same side of the body portion as its rear surface.
15. An assembly of any of claims 1 to 9 or 14, or a method of any of claims 10 to Is 13 or 14, wherein the elongate supports of the first subset are substantially C-shaped in transverse cross-section.
16 An assembly of any of claims 1 to 9 or 14 or 15, or a method of any of claims to 13 or 14 or 15, wherein the insulating material comprises cellulose fibre and/or mineral wool fibre.
17. A kit of parts for forming an assembly of any of claims 1 to 9 or 14 to 16.