AN INSULATION AND INSTALLATION FRAME FOR A SKYLIGHT WINDOW AND A METHOD FOR INSTALLATION OF A SKYLIGHT WINDOW BY USE OF SUCH A FRAME

Abstract: An insulation and installation frame for use in installing a skylight window in a pitched roof structure, comprising a roofing material, a batten structure serving as support therefor, a supporting arrangement of rafters (8) and an underroof placed on top of or between the rafters (8) and comprising at least one exterior, waterproof membrane (3) and an insulation layer (5), comprises top, bottom and side members (28, 29, 30) made from well insulating material and positioned in abutment against the upper side of the underroof and having a light opening (20) of the same size as a light opening made in the underroof (11a) but smaller than the exterior frame dimensions of the skylight window, such that the skylight window may be placed with its frame (11) in abutment against the upper side of the insulation and installation frame (20). At the mounting of the skylight window a marking-out of the window opening in the underroof is carried out by placing the insulation and installation frame (20) in abutment against the upper side of the underroof and by marking along the edges of the light opening (20a) of the frame (20).

Description: AN INSULATION AND INSTALLATION FRAME FOR A SKYLIGHT WINDOW AND A METHOD FOR INSTALLATION OF A SKYLIGHT WINDOW BY USE OF SUCH A FRAME The present invention relates to an insulation and installation frame for use in installing a skylight window in a pitched roof structure, comprising a roofing material, a batten structure serving as support therefor, a supporting arrangement of rafters and an underroof placed on top of or between the rafters and comprising at least one exterior, waterproof membrane and an insulation layer. The invention also relates to a method for installation of a skylight window in a pitched roof structure comprising a roofing material, a batten structure serving as support therefor, and an underroof placed on top of or between the rafters and comprising at least one exterior, waterproof membrane and an insulation layer, by use of such an insulation and installation frame. When installing skylight windows in pitched roof structures it is generally of great importance that the weather-protecting and insulating function of the structure is reestablished to the widest extent poss- ible at the transition between the frame structure of the skylight window and the surrounding roof construction. In the course of time, a number of in themselves good solutions with respect to establishing the neces- sary sealing between a skylight window and the roof structure has been proposed, i.a. through development of various types of flashing and connection skirts, with which the skylight window may be sealingly connected with the roofing material or the waterproof, weather-protecting external membrane in the underroof, as it is for instance known from EP-A-0 726 994, EP-A-0 730 698 and EP-A-0 756 569. These known solutions have not, however, to any appreciable extent aimed at reestablishing optimum insulation properties at the transition between the window and the roof structure, and it is in such installations a common phenomenon that thermal bridges through the frame and sash members of the window at big differences of temperature may cause visible formation of condensed water, in particular at the corners of the window light opening. The reasons for this may to a wide extent be due to the traditional craftsmanlike methods for installa- tion of skylight windows. By these known methods the external frame dimensions are measured first, following which a window opening of at least identical dimensions is cut out in the roof structure, room being left for the frame of the window to be countersunk at least partially in the window opening. At the installation a part of the roofing material is first removed, said material being slates, tiles or the like. Then a first rough measurement is performed of the load-bearing structure of batten members, which are situated within the area marked out for the window opening, and which now have to be removed. Subsequently, one more measurement on the underroof itself is performed, said underroof normally comprising an external waterproof membrane, for instance in form of reinforced, diffusion-tight or diffusion-open film, an underlying soft or hard insulation, a vapour sealing layer on the hot side of the insulation and usually an internal cover in form of for instance panels, boards, gypsum boards or the like, which are then finally cut out and removed. The last-mentioned measurement on the underroof very often causes problems, as it requires a correct measurement of the external dimensions of the window by use of several measuring tools up on the roof, before the cutting out of the window opening is commenced. The working conditions may contribute to the occurrence of errors during the measuring, in the most serious case such that the window opening becomes too big. The installation thus becomes difficult, time-consuming and resource-demanding. After the cutting out of the window opening, the actual installation of the window is performed, usually by use of a number of fittings, normally angle fit- tings, which are fastened both to the frame of the window and to members in the roof structure, for instance rafters or battens in such a way that the upper side of the window after the installation is positioned in a plane in parallel with and often above the plane of the roofing material. During this phase of the installation process an error may occur, for instance due to a wry position of the window relative to the plane of the roofing material, just as the work itself is difficult, time- consuming and resource-demanding. Finally, an external flashing of the window is carried out relative to the roof structure with a view to reestablishing the original "tight" roof structure, following which i.a. a reestablishing or internal reinsulation is made with a view to replacing insulation material which might be missing due to the cutting out of the window opening in oversize relative to the frame. If desired, an internal flashing by lining panels may be made with a view to creating a nice and functional transition to the wall covering of the room as such. During this phase of the installation process errors may occur i.a. in form of insufficient reinsu- lation, which typically entails a too big thermal loss through the window arrangement . The object of the invention is partly to provide a substantial improvement of the installation of a skylight window with a view to overcoming the above- mentioned problems in respect of thermal loss and formation of condensed water, partly to provide a substantially more simple and more specific installation process. In view of this the insulation and installation frame of the invention is characterized in comprising a frame with top, bottom and side members made from well insulating material and positioned in abutment against the upper side of the underroof and having a light opening similar to a window opening made in the underroof, but smaller than the exterior frame dimen- sions of the skylight window, such that the skylight window may be placed with its frame in abutment against the upper side of the insulation and installation frame . With such an insulation and installation frame a substantially better connection between the frame structure of the skylight window and the soft or hard insulation layer in the underroof around the window opening is obtained. By isothermal measurement and thermography such a displacement of isotherms away from the light opening of the window has been demonstrated that even at a difference of 35° between room temperature and outside temperature no visible formation of condensed water takes place at the corners of the light area. Advantageous embodiments of the insulation and installation frame appear from the dependent claims 2- 12. The method according to the invention is characterized in that after removal of the roofing material and said batten structure in an area corresponding to the external dimensions of the frame the insulation and installation frame is placed in abutment against the upper side of the underroof, following which indications are made for cutting out a window opening in the underroof of the same size as the light opening of the frame, the window opening is cut out, the insulation and installation frame is fastened in abutment against the upper side of the underroof, the light opening in alignment with the window opening, and the skylight window is mounted with its frame structure in abutment against the upper side of the insulation and mounting frame . On account of this a very exact and quick cutting out of the window opening in the underroof is obtained, such that the normally existing need for reestablishing the thermal insulation through reinsulation after the installation of the window no longer exists, and possible subsequent mounting of the internal linings may be made in direct continuation of the installation of the window. Advantageous embodiments of the method appear from claims 14 and 15. The invention will now be described in detail in the following with reference to the schematic drawing, in which Fig. 1 is a perspective and partially sectional view of the construction of a roof structure with conventional installation of a skylight window, Fig. 2 is a perspective and schematical view of a part of a window opening cut out in an underroof and an embodiment of an insulation and installation frame according to the invention placed in alignment therewith, Figs 3 and 4 are sectional views, perpendicular and parallel to, respectively, the rafters of a roof structure with a skylight window with associated lining panels built in by means of the insulation and installation frame according to the invention, Figs 5 - 7 are advantageous embodiments of the frame members in the insulation and mounting frame, Figs 8 and 9 illustrate the improvement obtained through the invention of the thermal insulation property at the transition between the skylight window and the surrounding roof structure, and Figs 10 and 11 illustrate the marking of a window opening prior to the installation of the skylight window . In Fig. 1 an example is shown of a roof structure without roofing material, which may usually consist of tiles, slates or the like roofing materials, and it is carried by a structure which in the example shown consist of battens 1 placed perpendicularly to the rafters 8, of which only cuts are shown in the figure, and counter-battens 2 extending in parallel with the rafters 8. 7An underroof construction positioned below the batten structure 1, 2, comprises in the example shown a 5 -layer construction which at the exterior comprises a waterproof membrane 3, which may consist of roofing felt, reinforced plastic sheeting or aluminium film and being either diffusion-tight , in which case suitable ventilation devices for airing the underroof may be mounted in the membrane, or open for diffusion of vapour . Below the membrane 3 a flashing 4 may, as shown, be placed on top of the rafters 8, said flashing typically consisting of boards or veneer sheets, and an insulation layer 5 at a certain distance from there and between the rafters 8, said layer being soft or hard and consisting of mineral wool, glass wool, wood concrete, plastic foam or the like. On the interior side the underroof may end in a vapour seal 6 in form of a plastic or alu foil laminate and on top of that an interior covering 7 which may consist of boards, panels gypsum boards or the like known covering materials. Other underroof constructions are of course also possible. The flashing 4 may for instance be left out, and, depending on the degree of hardness of the insulation material chosen, the insulation layer 5 may be positioned to support the membrane 3 completely or partially. In the roof structure shown in Fig. 1 the underroof is placed between the rafters 8, but it may also, as shown in Figs 3 and 4 , be placed on the very top of the rafters, such that the rafters are exposed on the interior side of the roof construction. In a window opening cut out in the underroof after removal of a suitable part of the batten structure 1, 2, a frame 11 for a skylight window has been mounted, which frame in a conventional manner is fastened to the roof construction, for instance as shown, to two counter battens 2 or to supporting battens 13 or through the construction and to the rafters 8, by means of fittings 12 in form of a traditional angle fitting, which may be nailed or screwed to both the frame 11 and the members shown in the roof construction. Above the frame 11, a water drain piece 9 inform of a substantially U-shaped profiled rail. In case of underroofs with a hard insulation layer the water drain piece 9 may be fastened directly thereto, as shown in Fig. 4, whereas in case of soft underroofs fastening may be made to the batten structure, for instance to the upper side of a batten 1. In the perspective partial view of Fig. 2 a part of the roof construction is shown schematically for illustration of the window opening 11a cut out in the underroof and the insulation and installation frame 20 according to the invention mounted around the window opening, the more detailed design and way of function- ing of which frame will be explained in the following. As shown by a dash-dot-line 22 the frame 20 is adjusted in height, such that its upper side is in alignment with the upper side of the batten 2. The planes of the two surfaces do not, however, necessarily have to converge, but may in some cases, for instance if the existing roof pitch is very small, advantageously intersect one another at a given angle to ensure the drainage of water from the window arrangement . In such cases a piece of the insulation and installation frame may be cut out to provide space for mounting fittings. The insulation and installation frame 20 is, as will further be seen from Figs 3 and 4, placed in abutment against the upper side of the exterior weather-shielding membrane 3 of the underroof. This underroof may besides be built up as shown and described, and as described before with a soft or hard insulation layer 5 lying and supporting said membrane 3 directly or at a certain distance therefrom. If the insulation layer 5 does not support the membrane 3, it is preferred that the insulation and installation frame 20 rests either on the rafters 8 or on thereto fastened lists or boards to ensure that the frame is placed in a well-defined position. The insulation and installation frame 20 has a light opening 20a in alignment with the window opening 11a in the underroof, whereas the light opening 20a has smaller dimensions than the exterior dimensions of the frame 11 of the skylight window, such that it may be mounted in abutment against the upper side of the insulation and installation frame 20. The insulation and installation frame 20 is according to the invention made as a frame body of well insulating material, preferably moulded mineral wool, wood concrete or the like. The frame may either be prefabricated in its finished shape, adapted to various types of windows or it may be delivered in form of profile lists, which may be adapted to different types of windows and assembled on location to a finished frame . Whether prefabricated or assembled on location, the frame 20 normally has a plane shape or contour fitting the frame of the window which it is to support and which is to be installed therein. Normally, the frame is thus rectangular or quadratic, but other shapes are possible too, for instance circular, semicircular, triangular, pentagonal, trapezoidal, etc. The frame 20 has preferably a substantially plane surface on the side facing the frame of the window. Also the surface of the frame 20 facing the underroof may be substantially plane, so that positioning and close fixation to the underrof may be carried out simply and quickly without the use of bigger amounts of glue or the like. To reduce the number of different types of frames, in particular in case of prefabricated ones, the frame 20 may be manufactured with a height corresponding to a maximum height of the batten structure 1, 2 and is therefore bigger than necessary in many cases of installation, the height adjustment to the roof con- struction in question being then possible during the installation by cutting off a piece of the under side of the frame. Alternatively, the frame 20 may be delivered adapted in size to the different types of windows in order thereby to reduce the consumption of material. The cross-section of the top, bottom and side members 28, 29 and 30 of the frame 20 or the therefor used profile lists may be substantially quadrangular, pentagonal or of other advantageous geometrical shapes . The frame cross section may in particular be made with a pitch, i.e. a wedge shape at the top member 28 and the bottom member 29 of the frame. Such a pitch of the top and bottom member 28, 29 ensures optimum insulation properties in the cases, where, out of consideration to the placing of the horizontal linings at the top of the window frame and vertical linings in the bottom, an oblique cut is made in the longitudinal direction of the bottom and top members of the frame 20, to provide space for the linings. In the embodiment shown in Figs 3 and 4 the frame 20 is around the light opening 20a provided with a circumferential rebate 25 for receiving and supporting the frame 11. The rebate 25 is in the embodiment shown on the side facing away from the light opening 20a defined by a list 24 protruding from the upper side of the frame, said list being cast integrally with the rectangular frame cross-section. As shown in Fig. 5 the list 24 may, however, advantageously be designed as a separate list of the same material, for instance moulded plastic foam, as the frame body itself for that matter, and retained in a groove 31 in the upper side of the insulation and installation frame 20, if said members 20, 24 are made from standard block elements, as it is only necessary to cut the keyway 31 and not necessary to remove material from both sides of the list for the formation of the groove. Besides, the list 24 does not have to follow the periphery of the light opening 20a all the way round, but may for instance be limited by angle members for defining corners for the rebate 25. In view of use in connection with skylight windows, in which the frame 11 as shown in Figs 3 and 4 at its under side is provided with grooves 26 for receiving linings 17, the rebate 25 may advantageously have a width which is smaller than the distance from the external side of the frame members to the groove 26. Between the external side of the insulation and installation frame 20 and the outer side of the list 24 protruding from the upper side of the frame a reinforc- ing and supporting list 21 may be provided, as shown in Figs 3 - 6, said list being manufactured for instance from solid wood or plywood, plastics or fibre-reinforced concrete plastics or the like - for reinforcing the frame body and preferably fastened thereto, for instance by gluing. The list 21 is made in such a way that it follows the frame pieces and may be used for fixing the individual frame members relative to each other, for instance by means of screws. The mounting of such a list further entails an advantageous equalizing of the pressure load acting on the frame 20, when it by means of screws is fixed to the underlying rafter structure . The reinforcing and supporting list 21 will normally be made from solid wood or plywood and in the same lengths as the frame members 28 - 30, but may possibly also be made in shorter pieces. The lists must, however, be of such a length that they can also serve as supporting list for the fittings 12 for the frame 11, if these are fastened to the frame 11, the list 21 and the batten structure 1, 2, respectively, by means of screws . In view of the afore-mentioned height adjustment of the insulation and installation frame to the distance between the upper side of the underroof and the upper side of the uppermost battens in the batten structure 1, 2 in an existing roof construction the frame members 28 -3 0 or the profile members used therefor may, as shown in Figs 5 and 6, be made with prefabricated or premarked recesses 32 on the interior and the exterior sides, which faces/faces away from, respectively, the light opening 20, such that a height adjustment as shown in Fig. 6 in a simple manner may be performed by breaking off material from the frame cross-section. These recesses 32 may as illustrated be slightly downwards inclining from the middle and outwards or extend substantially plane relative to a frame with a plane bottom, and may besides advantageously serve as guides for instance for a cutting tool in connection with the cutting work involved in the height adjustment. The insulation and installation frame 20 may normally be made with a plane underside for abutment against the upper side of the underroof, but as shown in Fig. 6 it may in view of placing a sealing strip 33, for instance of bitumen or impregnated polyurethane foam, in order to prevent humidity from penetrating between the insulation and installation frame and the underroof, be advantageous to design the underside of the frame as a slightly V-shaped groove 34. As mentioned in the preceding it may with a view to avoiding manufacture of solid-cast insulation and installation frames according to the invention in a number of different sizes and dimensions corresponding to the existing dimensions of skylight windows be advantageous to manufacture the frame on location by cutting off the frame pieces from profile lists made for that purpose and subsequently assemble the frame pieces. The joints may be made as per se conventional mitre joints, but for the attainment of optimum tight- ness of the joints and in order to facilitate the work involved in cutting and assembling the frame members, it may as shown in Fig. 7 be advantageous, if the frame pieces for the top and bottom members 28, 29 of the frame are made in finished length corresponding to the existing width measure of skylight windows, such that adjustment by cutting off the profile lists is alone made in respect of the frame members, which are to form the side members 30. The frame members 28, 29 may in this connection be provided with recesses 35, 36 for shape-matching abutment against planely cut end faces of the side frame members 30, which are manufactured in desired length by cutting from the above profile lists. For illustration of the improvement obtained of the heat insulation property at the transition between a skylight window and the surrounding roof structure, such that formation of condensed water also at the lower corners of the pane area of the window to a wide extent is avoided even in case of big differences of temperature between the interior surface and the exterior surface of the window, the isothermic course is shown in Figs 8 and 9 of a skylight window built into a roof structure according to conventional installation technique, and by use of the insulation and installation frame according to the invention, respectively. As will be seen the insulation and installation frame typically entails at a room temperature of 20 °C and an outdoor temperature of -15°C that the 10° isotherm is moved outside of the pane area of the window to the frame and sash structure . This improved insulating property is mainly due to the fact that the insulation and installation frame according to the invention makes a substantially more exact cutting of the window opening 11a in the insulation layer 5 of the underroof possible with side walls in alignment with the interior side faces of the insulation and installation frame facing the light opening 20a. Thereby, the need for reestablishing the insulation property by a reinsulaton after the mounting of the window does not exist . The exact making of the window opening 11 is obtained by the method according to the invention by starting, as usual, by removing the roofing material in the area necessary opposite the desired window opening. Then a rough measurement is performed before removal of the batten and counter batten members 1, 2. A precise measurement of the window opening to be established in the underroof may now be made by placing the insulation and installation frame 20 as shown in Fig. 10 in direct abutment against the upper side of the underroof, whereby an exact marking of the edge of the window opening may be made through the light opening 20a of the frame. After removal of the frame 20, the window opening 11a may be cut exactly in accordance with the marking made by traditional cutting tools. The possibility of making mistakes during the measuring process does not substantially exist. Depending on the actual construction of the underroof the insulation and mounting frame is then fixed to underroof, for instance by means of glue, tape or sealing strip. In case of the exterior layer of the underroof 3 being constituted by a diffusion-tight membrane, tight connection therewith may be established in a manner known per se by means of a sleeve or a collar, for instance as disclosed in the above-mentioned EP-A-0 756 569, which sleeve or collar is fixed partly to the frame of the window partly to the dif- fusion-tight membrane. In case of a diffusion-open membrane it may be sufficient to use ordinary water drain pieces placed above the window as shown in Fig. 1. After fastening of the insulation and installation frame 20 the window frame 11 can be mounted without any problems on the frame and besides be fastened in the usual way to the rafters or the battens in the roof structure by means of the fittings 12. After the mounting a broad gummed tape 37 may be provided all along the window frame, said tape being fastened to the exterior side of the frame 11 and the upper side of the insulation and mounting frame as shown in Figs 3 and 4 for sealing the transition between the frame and the sash 20. Due to the very exact and quick cutting of the window opening, the subsequent internal mounting of the linings 17 in Figs 3 and 4 may be performed immediately and in direct continuation of the installation of the window, the traditional reestablishing of the insula- tion layer by reinsulation not being necessary any longer.

Claims: P A T E N T C L A I M S 1. An insulation and installation frame for use in installing a skylight window in a pitched roof structure, comprising a roofing material, a batten structure serving as support therefor, a supporting arrangement of rafters (8) and an underroof placed on top of or between the rafters (8) and comprising at least one exterior, waterproof membrane (3) and an insulation layer (5), c h a r a c t e r i z e d in comprising a frame (20) with top, bottom and side members (28, 29, 30) made from well insulating material and positioned in abutment against the upper side of the underroof and having a light opening (20) similar to a window opening made in the underroof (11a) , but smaller than the exterior frame dimensions of the skylight window, such that the skylight window may be placed with its frame (11) in abutment against the upper side of the insulation and installation frame (20) . 2. An insulation and installation frame according to claim 1, c h a r a c t e r i z e d in that at the upper side of the frame (20) around its light opening (20a) a rebate (25) is provided for receiving the main frame of the skylight window (11) . 3. An insulation and installation frame according to claim 2, c h a r a c t e r i z e d in that said rebate (25) is defined by a list (24) protruding from the upper side of the frame (20) and being made from a good heat-insulating material. 4. An insulation and installation frame according to claim 3, c h a r a c t e r i z e d in that said strip (24) is made as a separate strip retained in a groove (31) in the upper side of the frame (20) . 5. An insulation and installation frame according to claim 2, 3 or 4 , for a skylight window, the frame members of which at the underside are provided with longitudinal grooves (26) for receiving lining panels (17) , c h a r a c t e r i z e d in that said rebate (25) has a width which is smaller than the distance between said grooves (26) and the exterior sides of the frame members . 6. An insulation and installation frame according to any of the preceding claims, c h a r a c t e r i z e d in that a supporting list (21) is fastened to the upper side of the of the frame members (28, 29, 30) for supporting said well insulating material and for supporting and fastening of mounting fittings (12) for the skylight window. 7. An insulation and installation frame according to claim 6, c h a r a c t e r i z e d in that said supporting list (21) is placed between the exterior side of said protruding list (24) and the exterior side of the insulation and installation frame (20) . 8. An insulation and installation frame according to any of the preceding claims, c h a r a c t e r - i z e d in that in the side faces of the frame members (28, 29, 30) notches (32) are provided substantially in parallel with the under side of the frame members for use in reducing the height of the frame (20) by removal of material from the frame members in view of adjusting the height of the frame to an existing roof construction, such that the upper side of the insulation and installation frame may be arranged in alignment with the upper side of the batten members (1, 2) positioned closest to the underside of the exterior roofing. 9. An insulation and installation frame according to any of the preceding claims, c h a r a c t e r i z e d in that the underside of the frame members (28, 29, 30) is designed as a groove, the cross-section of which is slightly V-shaped, for receiving a sealing strip (33) . 10. Insulation and installation frame according to any of the preceding claims, c h a r a c t e r i z e d in that it is made from moulded plastic foam material. 11. Insulation and installation frame according to any of the preceding claims, c h a r a c t e r i z e d in that it is assembled on location from profile lists for the formation of frame members. 12. Insulation and installation frame according to claim 6, c h a r a c t e r i z e d in that profile lists (34) for the formation of the top and bottom members (28, 29) are manufactured in finished lengths corresponding to the width dimensions of skylight windows and with end recesses (35) , the shape of which is adapted to be assembled with plane, cut end surfaces of profile lists (36) for the side members of the frame, which are made in lengths corresponding to the biggest window height for a given window width, but which may when shortened be adapted to lower window heights . 13. A method for installation of a skylight window in a pitched roof structure comprising a roofing material, a batten structure serving as support therefor, a supporting arrangement of rafters (8) and an underroof placed on top of or between the rafters (8) and com- prising at least one exterior, waterproof membrane (3) and an insulation layer (5) by use of an insulation and installation frame (20) according to one of the preceding claims, c h a r a c t e r i z e d in that after removal of the roofing material and said batten struc- ture in an area corresponding to the external dimensions of the frame (20) the insulation and installation frame (20) is placed in abutment against the upper side of the underroof, following which markings are made for cutting out a window opening (11a) in the underroof of the same size as the light opening (20a) of the frame, the window opening (11a) is cut out, the insulation and installation frame (20) is fastened in abutment against the upper side of the underroof with the light opening (20a) in alignment with the window opening (lla) , and the skylight window is mounted with its frame structure (11) in abutment against the upper side of the insulation and mounting frame (20) . 14. A method according to claim 13, c h a r a c - t e r i z e d in that between the underside of the insulation and installation frame (20) and the upper side of the underroof a sealing strip (33) is provided. 15. A method according to claim 13 or 14, c h a ra c t e r i z e d in that the upper and lower side of the window opening (lla) made in the underroof is adapted for the mounting of lining panels (17) in a horizontal and a vertical plane.

Inventors: ALKJAER PETER, SOERENSEN PETER, ALKJAER, PETER, SOERENSEN, PETER
Applicants: ALKJAER PETER, RASMUSSEN KANN IND AS, SOERENSEN PETER, ALKJAER, PETER, SOERENSEN, PETER, V. KANN RASMUSSEN INDUSTRI A/S
Application year: 1997
Main classification: E04D13
IPC codes: E04D13