The present invention relates to an insulating member for use between a window and a load-bearing structure, to a window including such an insulating member, to a roof structure including such a window and to a method of insulating a window using such an insulating member.

The insulating member is intended primarily for use with windows mounted in an inclined roof structure comprising a load-bearing structure including a plurality of battens arranged on the load-bearing structure and a roofing material arranged on the battens. The joint between the window and the roof structure is sealed by means of a flashing frame, which may be a unitary frame, but which is usually composed of a number of flashing members. The flashing has a first leg lying substantially in the plane of the roof between the battens and the roofing and a second leg extending at an angle with respect to the first leg and lying substantially parallel to the outer side of the window.

EP-A1-0679773 discloses a window of this type, where an insulating member constitutes the upper outer part of the window frame. In this way the section of the window frame, which is above the rafters, and thus also above the roof insulation in the mounted state of the window, is insulated towards the exterior. This provides for far better properties with regards to insulation than when using a traditional all-wooden frame. The total frame width is, however, relatively large, which entails that the ratio of dimensions between the effective pane area contributing to letting light into the building and the size of the hole, which must be made in the roof, is relatively small.

Another way of achieving an insulation of a roof window is known for example from EP-B1-1706557, where an insulating frame is applied on the outer side of the window, and from PL-B1-205441, where additional insulation is part of the flashing. These solutions suffer from the disadvantage that a gap corresponding in size to the height of the battens and counter battens is present between the additional insulation and the roof insulation. This gap is usually filled manually with a deformable insulating material such as mineral wool, but it is also possible to provide supplementary insulating frames as taught in EP-B1-1706557. EP 2 182 132 A2 and EP 1 550 777 A1 disclose also insulating members for insulation of skylights.

The latter solution to the problem is very efficient but necessitates the removal of the ends of the battens closest to the window to make room for the insulating frame(s) and the mounting of combinations of insulating frames implies a risk of erroneous mounting. The risk of faulty work also exists when using mineral wool, since craftsmen are often tempted to skip this work or do it without applying the necessary care.

It is therefore the object of the invention to provide for easy insulation of windows, where the insulation properties are improved without necessitating a smaller effective pane area.

This object is achieved with an insulating member as defined in claim 1. The compressible insulating material of the second insulating element is capable of adapting to the shape of the load-bearing structure. This means that it is not necessary to cut away the ends of the battens and the window can be made so that its frame corresponds in the size to the hole in the roof. The compressible insulating material will give way and make room for the battens, while filling out the space between them, and will similarly adapt to other variations in the roof structure. This leads to an efficient insulation all the way down to the rafters, counter battens or underroof depending on the construction of the roof.

If the second insulating element is simply a strip of compressible insulating material, the compression above the battens will tend to pull the sections of the second insulating element neighbouring the batten away from the window frame. This has a negative impact on the insulating properties and might potentially course a displacement of the entire insulating member. In that case the second insulating element should therefore be attached to the window frame or the batten, preferably at level with the upper side of the batten.

To increase the ability of the second insulating element to adapt to the roof structure and solve the problems associated with using a simple strip of insulation material described above, the second insulating element is made from a slit material. The slits are arranged so that they extend in the height direction from the lower side and preferably in a plane, which is substantially perpendicular to a length axis of the insulating member. Such slits allow different sections of the insulating material to be displaced in relation to each other and allow one section to be fully compressed above a batten, while the neighbouring section is fully expanded and following the sides of the batten all the way down.

Likewise, slits extending from the lower side and in a plane, which is substantially parallel to a length axis of the insulating member, the ability of the second insulating element to fill out the space, which is often found between the end of a batten and the window frame, is increased.

It is of course also possible to have two sets of intersecting slits. This will provide optimal adaptability, but also involves a more complicated manufacturing process and hence makes the product more expensive. Likewise, weakening sections may be provided instead of the slits, said weakening sections, which form a series of weak walls in the material, being broken in appropriate places when the material is compressed. If choosing to use such a more complex material, it is preferred that slits and/or weakening sections are arranged so that they do not form straight lines through the material. When the material is compressed, such lines may be opened and thus form thermal bridges having a negative impact on the insulating properties. Using several second insulating members arranged close to one another still further from the window frame and having different or off-set patterns of slits and/or weakening sections is an effective way of preventing such lines.

For achieving optimal insulation the second insulating element should be at least as high as the batten. In typical European roof structures the battens are from 14 to 38 mm thick and it is therefore preferred that the second insulating element has a height seen in the height direction of 20-60 mm, preferably 50 mm. Even thicker battens do occur, examples being those of 45 mm used in Denmark and those of 60 mm used in some Swiss and Austrian buildings. To accommodate these, the second insulating element should have a height of 70-75 mm and slits of 60-65 mm, but as these sizes are rarely used it is presently considered advantageous to provide a specialized product of increased height for these purposes.

The dimensionally stable insulating material is located at the upper and most exposed part of the window, which may be subject to weather-induced loads and impacts originating from traffic on the roof, for instance in connection with maintenance work. Apart from being able to withstand these factors, the use of a dimensionally stable material allows for the attachment and support of flashing members and it may also contribute to the load-bearing properties of the window. The first insulating element may even be made so sufficiently strong that it can transfer the weight of the window to the rafter, making traditional mounting brackets for anchoring the window to the load-bearing structure unnecessary.

Another advantage of using a first insulating element of a dimensionally stable insulating material is that such materials are generally less sensitive to moisture and heat, which are factors having greater influence at the upper outer side than at the lower side, where the second insulating element is located.

The special properties of the second insulating elements are particularly useful at those sides of the window, which are arranged at an angle to the battens. Second insulating elements may therefore be provided only at the sides of rectangular windows and not at the top and bottom. Likewise, different insulating frame pieces may have different second insulating elements depending on their intended use, an example being that the second insulating element may be reduced in size at the bottom of the window.

The insulating members may be delivered and mounted individually and it is even possible to make them in situ by interconnecting the first and second insulating members by hand. Particularly the task of providing a proper interconnection at the corners of the window will, however, be relatively cumbersome. It may therefore be advantageous to deliver pre-assembled frames or sets of frame components, especially when intended for use on windows of standardized sizes.

In this, the use of the insulating member is described with relation to a roof window, but it will be understood that it may also be used for insulating façade windows etc. whenever these are mounted in an uneven structure.

The fastening means may be any suitable means for connecting the insulating member to the window or the load-bearing structure so that it is kept close alongside the window. Examples are adhesives, such as a pressure sensitive adhesive applied during manufacture, a hot-melt adhesive applied in situ or a double sided tape applied to the first insulating element with a cover foil to be removed immediately prior to attachment. Other examples are nails driven through the first insulating element and into the window frame or load-bearing structure, or brackets attached to the first insulating member, possibly being embedded in the material thereof. Still further examples are interlocking means with matching members on the window or load-bearing structure, which could be simply a recess matching a corresponding projection on the window frame or load-bearing structure, but which might also be a hook and loop system like Velcro®.

When using brackets, these may serve as mounting brackets for transferring loads from the window to the load-bearing structure, but this makes heavy demands on the properties of the material used for the first insulating element and is therefore rarely expedient. Instead the window will be attached directly to the load-bearing structure in a traditional manner using a separate set of mounting brackets. In this case the first and/or second insulating elements may be provided with recesses accommodating at least a part of the mounting brackets. Some types of mounting brackets are post-fitted at the installation site and the recesses may therefore be provided as tear-away parts of the insulating frame pieces or provided with plugs when not in use. This also allows for a wider of use of the insulating frame pieces, since they may be designed for use in windows demanding many brackets and still be used in windows demanding fewer brackets, a suitable number of recesses being prepared in each case.

Other elements to be attached to the window or to the load-bearing structure in the close vicinity of the window may also be provided as part of the insulating member, examples being flashing members, sealing strips, vapour barriers and underroof collars. These are preferably attached to the first insulating member by means of an adhesive, but mechanical means such as staples may also be employed as well as several other means readily imaginable to the skilled person.

Vapour barriers and underroof collars are made from relatively wide sheets of material, which may be difficult to handle if delivered in the intended state of use. It is therefore preferred that these are provided in a folded state, where they are located along the side of the insulating member, so that they do not project below the lower side of the insulating member. A small projection may, however, be acceptable as long as it does not interfere with the mounting of the insulating member. Once the insulating member has been attached in its intended position, any vapour barriers and underroof collars may be unfolded to their position of use and a separate attachment of these at the window frame is no longer necessary.

The advantageous properties of the second insulating element described above may also be utilized at other places, e.g. at the joint between the flashing and the roofing. It is customary to provide a sealing element made from a compressible insulating material and attached to the first leg of the flashing member on the side facing the roofing. See for example WO03/048478. This prevents birds, leaves, precipitation etc. to enter underneath the roofing, which is particularly important when using tiles or like roofing materials of irregular shape. By using a sealing element, which is substantially identical to the second insulating element, the number of different components needed for the manufacture of the window is kept at a minimum and the excellent capability for adaptation described above may be utilized once more.

In the following the window according to the present invention will be described in further detail with reference to embodiments shown on the accompanying drawing, where:

• Fig. 1 depicts a window mounted in an inclined roof,
• Fig. 2 is a cross-sectional perspective view of the side of a window according to the invention mounted in a roof structure,
• Fig. 3 shows the window in Fig. 2 seen from the side,
• Fig. 4, new is a cross-sectional view of the bottom of a window according to the invention mounted in a roof structure,
• Fig. 5 is a cross-sectional view of a second embodiment of the side of a window according to the invention,
• Fig. 6 shows the joint between flashing and roofing at the top of the window, and
• Fig. 7 is a cross-sectional view of a third embodiment of the side of a window according to the invention.

Like reference numbers will be used throughout the drawing for parts having similar or analogous function, but this is not to be taken as an indication that such parts found in different figures are necessarily identical.

A roof window 1 mounted in an inclined roof 2 is shown in Fig. 1. Here, the roofing 3 is of a flat type, but as will be explained later with reference to the other figures, other types of roofing may also be used.

The window comprises a window frame having a plurality of frame pieces. In order to provide a weather-tight transition between the window and the surrounding roofing, these are covered by a number of flashing members 11-14, cover members 21-24 and cladding members 31-34 and are therefore not visible in Fig. 1. In all of the embodiments shown in the drawing, the window is rectangular and the window frame comprises four frame pieces, where only the right-hand frame piece 41 only is visible in Fig. 2, the bottom frame piece 42 in Fig. 4 and the lefthand frame piece 43 in Fig. 5. The window furthermore comprises a window sash 5, which is openable with respect to the window frame.

Each cover member 21-24, although of different configuration, has a first leg for covering the upper side of the corresponding frame piece and a second leg covering a part of the outer side of the frame piece. Throughout the description the term "inner side" is used about the side of window frame pieces, insulating members etc. which faces the opening in the window frame, while the term "outer side" is used about a side facing away from the opening. Likewise, the term "upper side" is used to indicate a side facing upwards in the mounted position, i.e. towards the exterior of a building, and the term "lower side" is used to indicate a side facing downwards, i.e. towards the interior of a building.

In the embodiment shown, the flashing frame includes four flashing members 11-14, each having a first leg lying substantially in the plane of the roof and a second leg extending at an angle with respect to the first leg covering a part of the outer side of the frame piece and being partly overlapped by the second leg of the corresponding cover member. At the intersection between adjoining flashing members, the flashing members may be connected with each other in any suitable manner, e.g. by folding, welding or by any other method and the same applies to the cover members. In Fig. 1 the flashing members are shown with integrated corner sections, but it is also possible to provide a plurality of separate flashing corner members for connection of adjoining flashing members. Water gathered at the top of the window is led down along the sides of the window and further down to the roofing below the window via a skirt 15 in a manner known per se. Here the flashing is composed of several members, but a unitary flashing may of course also be utilized, just as the number and arrangement of cladding and covering members may vary.

Figs. 2 and 3 show simplified views in cross-sectional perspective as indicated by the line II-II in Fig. 1 and from the side, respectively, where the window is represented only by the right-hand frame piece 41 and where roofing and flashing have been removed to lay open the roof structure 20 and the insulation.

In the embodiment shown the roof structure 20 is composed of a series of rafters 6, only one of which is shown, an underroof 7 clamped between the rafter and a counter batten 8 above each rafter, and finally a series of battens 9 arranged perpendicularly to the rafters and counter battens.

The window 1 may be secured to the load-bearing rafters or the counter battens by means of traditional mounting brackets (not shown) provided at the side frame member or at the corners between adjoining frame pieces.

An insulating member 10 according to the invention comprising a first insulating element 101 and a second insulating element 102 is attached to the outer side of the window frame piece 41 by means of screws 103 and it is further attached to the battens 9 by means of a bracket 104. In this way the attachment of the insulating member 10 will contribute to the attachment of the window itself and if the first insulating element 101 is sufficiently strong, traditional mounting brackets may be left out entirely. The more usual situation, however, will be that the insulating member 10 is attached either to the window frame piece 41 or to the battens 9 instead of to both as depicted here.

The bracket 104 on the insulating member 10 is depicted as an L-profile extending over the entire length of the insulating member. This substantially eliminates the risk of erroneous mounting, since the bracket 104 will not be misplaced in relation to the battens 9, and provides strength and stiffness, but it is also possible to use smaller brackets located at each or some of the battens.

In an even more simple embodiment, the first insulating element 101 is simply provided with an adhesive 109 (see Fig. 5) on the side facing the window frame piece 41. In this way the insulating member may be attached either before or after mounting of the window, which is kept in place using traditional mounting brackets.

The second insulating element 102 extends from the lower side of the first element to the upper side of the counter battens 8 and has been compressed above the battens 9. According to European building traditions most battens have a height h of 14-38 mm depending amongst others on the type of roofing used. To be able to adapt to this, the second insulating is made with a height of 50 mm. Larger sizes may, however, occur. According to the invention, the second insulting element 102 is provided with slits 105 allowing different sections of the element to be compressed independently. These slits should of course be at least as deep as the height h of the battens, here 40 mm.

Referring now to Fig. 7, the second insulating element may also fill out a space between the end of the batten and the window frame and even extend underneath the window frame. To achieve this, the second insulating member may be provided with slits (not shown) extending substantially parallel to a length axis of the insulating member or a combination of slits both perpendicular and parallel to the length axis. Slits at other angles are of course also a possibility and so is the use of any other material allowing different sections to move independently. An example could be a honeycomb structure, where the different cells are interconnected by relatively weak walls that can be easily broken, thereby allowing the cells to move in relation the each other.

Regardless of the orientation of the slits, there is a risk that the compression results in the one or more slits in the material next to a batten or other projection being pulled slightly open. This provides a direct channel through the insulation, which of course affects the insulating properties negatively. It is therefore considered advantageous to use a material having several series of slits or weak walls, which are off-set in relation to each other, so that any opening formed will be non-straight, preferably forming a labyrinth. This may be achieved with complex patterns of cuts and/or weak walls. It is, however, also possible to provide two or more separate second insulating elements arranged side-by-side, one at the window frame and another on the outer side of the insulating member, and with slits/walls off-set in relation to each other.

In the embodiment shown in Figs. 2, 3 and 5, the first insulating member 101 has a height of approximately 90 mm, which allows for the window to be mounted relatively high in the roof. If it is desired to have the window mounted deeper in the roof, the height of the first insulating member should be reduced and it may therefore be provided lines or other markings indicating where to cut or with tear-off means. It is of course also possible to use a smaller height and leave the uppermost part of the frame un-insulated when mounting the window in a high position. This is, however, less preferred since it will not only make the window less well insulated but also entail a complication of the total shape of the window with insulation, which may complicate mounting, particularly of the flashing and covering members.

The upper side of the insulating member 10 need not be flush with the upper side of the window frame and it may advantageously be made with a small inclination, for example 15 degrees, away from the window frame in order to facilitate drainage as shown in Fig. 5.

It is also possible to use a first insulating element 101 of a triangular cross-sectional shape (not shown), so that its width is zero at the level for the upper side of the window frame, or of a more complex shape, for example with an upper half having a curved outer side. The shape should, however, not be made unnecessarily complicated as this will usually influence the shape of flashing and covering members.

In the above the first and second insulating elements have been described as being located one above the other. It is, however, to be understood that one or both may be provided with projecting parts extending along the other, so that for example a projecting part of the first insulating element 101 is sandwiched between the window frame and the second insulating element 102.

The insulating members 10 may in principle have any extent in the longitudinal direction, but it is advantageous if the insulating member extends over substantially the entire length of the corresponding window frame piece.

As may be seen in Fig. 4 there is not much space for insulation at the bottom of a typical roof window and in this embodiment the first insulating element has therefore been left out entirely.

As described above, the window can be secured to the underlying roof structure by means of mounting brackets, which are typically angular and attached to the side pieces of the window frame by means of a first leg. In order to accommodate this leg, the insulating members may, at least at the side pieces, be provided with recesses. One possible design of forming such recesses is that the inner side of the insulating member, is provided with a number of weakening lines in the height direction. The weakening lines may e.g. be provided as perforations extending to a predetermined depth in the width direction of the insulating member. It is to be understood that a corresponding section of the material of the insulating member is only fastened to the remaining section thereof along these weakening lines. A suitable distance between the weakening lines is chosen such that one or two sections of material between adjacent weakening lines are torn away in order to provide a recess to accommodate the first leg of the mounting bracket. It is of course also conceivable to form the insulating element without potential recesses, and to form the recesses manually. Eventually, the insulating frame may be used without recesses altogether.

The first and second insulating elements 101, 102 may be made from polyethylene (PE) foam, which combines advantages with regards to handling, price and environmental consideration, but any other suitable material may be used, including polypropylene (PP), polyvinylchloride (PVC), expanded polystyrene (EPS), extruded polystyrene (XPS) or mineral wool. Using the same material of a difference density or different surface characteristics for both the first and the second insulating element has the advantage that the two elements will have substantially the same properties and do not tend to degrade each other chemically, but combinations of materials are also within the scope of the invention.

If using a material suitable for extrusion, the insulating elements 101, 102 may e.g. be produced as a coherent string of extruded material that is cut into appropriate lengths. These pieces of material may then be attached to each other in pairs so as to serve as first and second insulating elements, respectively, but depending on the material(s) used it is also possible to coextruded them.

The insulating members 10 can be simply attached at each side of the window frame but it is preferred that they are interconnected to form an insulating frame. This may be done using any kind of joint, e.g. mitred joints, and the frame may be made in situ or delivered in the assembled state. It is also possible to provide a unitary insulating frame made from a single insulating member, which has been bent into shape.

Other elements may also be included in the insulating member according to the invention as shown in Fig. 5. One example is the sealing strip 106 for sealing the joint between the upper sides of the first insulating element 101 and the frame 43 or for sealing directly against the pane (not shown). Such a sealing strip 106 can be co-extruded, added using a caulking gun, attached using a pressure sensitive glue or in any other suitable manner.

Other examples are attachment means for attachment of an underroof 7, an underroof collar 71 or a vapour barrier 72. In Fig. 5 the vapour barrier 72 is attached by means of an adhesive 107 and the underroof collar 71 is attached in a groove 108. Here, the groove is made in the first insulating element and is relatively narrow so that it clamps the edge of the underroof collar by the resilience of the material. The groove could, however, also have been made in the joint between the first 101 and second 102 insulating elements and/or the clamping effect could have been achieved by forcing a string, rod or list (not shown) into the groove as will be readily conceivable to the skilled person.

The underroof collar 71 and/or vapour barrier 72 could also have been integrated in the insulating member. In one embodiment the first 101 and second 102 insulating elements are made separately and interconnected by a gluing process where also the underroof collar and vapour barrier are attached in the glue joint. Another option is to embed the edge thereof in the material of one of the insulating members.

Having the underroof collar 71 and vapour barrier 72 in their position of use as depicted in Fig. 5 when mounting the insulating member 10 would make the work relatively difficult, since particularly the vapour barrier would tend to get in the way. It is therefore preferred that, in the state of delivery, the underroof collar 71 and vapour barrier 72 are in a folded state, where they lay along the outer and inner sides of the insulating member, respectively, and do not project below the lower side thereof. Once the insulating member 10 have been attached, the underroof collar and vapour barrier are unfolded to the position shown in Fig. 5, where the bends represent longitudinal folds. It is of course also possible to provide the underroof collar and/or vapour barrier in a rolled up state.

At the top of the window, the roofing 3, which is here tiles, overlaps the top flashing member 14, which is partially cut away in Fig. 6, so that water is led from the roofing above the window 1 via the flashing and back onto the roofing below the window. When using tiles or like roofing materials the top flashing member is usually provided with a tile support on which the lower ends of the tiles rest so that they are kept level with the tiles in the same row next to the window. This tile support may be embodied in the same way as the insulating member 10 according to the invention, but mounted upside-down as shown in Fig. 6. The dimensionally stable material 101', which is here attached to the top flashing member 14, has a height corresponding substantially to the height of the battens and works in substantially the same way as a traditional tile support. Cutting lines or tear-off means may be provided for allowing an easy adaptation of the height.

The compressible material 102' on top, which is facing with the slits 105' upwards, is able to adapt to the shape of the roofing material so that snow, bird etc. is prevented from coming up underneath the roofing. Fig. 6 shows how tiles depress sections of the compressible material, while leaving other sections substantially unaffected. It will be understood that the height of the compressible material should correspond at least to the dept of the hollows found in the roofing material in order to work properly and that this height may differ from that of the second insulating element 102 described above. It is of course also possible to use a material without slits, particularly when using tiles which represent relatively soft curves.

A similar effect may be achieved at the side members of the flashing, but here there is usually no need for elevating the roofing material, and the dimensionally stable material may therefore be left out entirely.

Sealing members for use between the roofing material and the flashing members as described above is preferably attached to the flashing members in the state of delivery, but may also be post-fitted. In the latter case or when using a fully or partially unitary flashing, the top and side sealing members may be made as one coherent member. Attachment may be achieved using double sided tape or any other suitable means for attachment. It may, however, be advantageous that the sealing members are attached using the same means for attachment as those used for attaching the insulating members and/or for interconnecting the first and second insulating members, particularly when using sealing members identical to the second insulating element.

The invention should not be regarded as being limited to the embodiments shown. On the contrary, various modifications and combinations will be within the scope of the appended claim.