Method of improving the thermal insulating ability of a building construction

Abstract

 In a building having a layer of thermal insulating material, for example mineral wool, the wind stop outside of the insulating material and the steam stop inside the thermal insulating material are united to completely airtight enclose the insulating material. All joints in the stops and between the stops are cemented to provide for airtightness. Both the steam stop (the diffusion stop) and the wind stop are made up by strong tough paper. Jointing tape having thermal cement coating on one side and an electric iron are used for making the airtight joints. The wind stop of the walls and the roof are preferably united to form one single layer for the entire building.

Description

[0001] The invention relates to a method of improving the thermal insulating ability of a building construction that has a layer of a thermal insulating material, wherein a diffusion stonping layer is used inside of the insulating material and a wind stop is used outside of the insulating material.

[0002] The thermal insulation is reduced in rior art constructions since the constructions are not tight enough. Light constructions in particular tend to be untight in the long run because of the continaual variations in outdoor temperature and humidity. For example, hard board sheets nailed to a wooden framework tend to be untight in the joints because of the thermal and humidity movements in the board itself. It should also be noted that a brick wall, whether used as tne bearing wall or as a panel, is not sufficient as a wind stop because of it pores. Therefore also in prior art constructions where material with excellent thermal insulating properties are used, for example mineral wool, the thermal insulation is not very good due to the lack of tightness.

[0003] Thus, it is an object of the invention to provide for an improved thermal insulation. This is accomplished by improving the tightness defined in the claims.

[0004] The invention will further described with reference to tne accompanying drawings.

Figure 1 is a schematic and fragmentary section tnrougn a new 1

storey nouse to whcih the invention is applied.

Figure 2 s ov-s details of Fig. 1 on a larger scale.

Figure 3 shows a roof truss that is also partly shown in Fig. 1.

Figure 4 is a schematic and fragmentary section through an existing house to which the invention is applied during reconditioning.

Figure 5 shows details of Fig. 4 on a larger scale.

Figure 6 shows a connection stripused to tighten against door and window frames.

Figure 7 shows a collar for electric joint boxes.

Figure 8 shows an end strip used to- tighten against a wall.

[0005] Fig. 1 shows schematically the invention applied to a new house in light construction, that is, a house with wood frame work walls and a layer of mineral wool between the wood battens of the frame work. The house has a foundation in the form of a concrete slab that rests on a layer of a non-illustrated thermal insulating material on the ground. The frame work of the walls is not shorn. A roof truss 14 is shorn separately in fig. 3. It comprises raf.ters 15, a tie 16 and a top batten 17. The rafters do not extend outside the walls and they do not make the roof top, but the roof is a separate construction that rests on the rafters 15 and forms the eaves 13 and the roof top 18. Wind stonping paper is attached to the roof truss 14 around the tie and the rafters at their connection and sealingly cemented to a strip 20 of paper.

[0006] Wind stopping paper 22 from a roll is mounted by means of staples to the outside of the frame work of the walls and roof, i.e. outside of the mineral wool 21. The strips of the wind stopping paper 22 overlap and the strips are stitched so that the staples are covered by the overlap of the next strip. All the joints are tightened by jointing paper tapes that have one side coated with a thermal cement so that they can be affized to the wind stopping paper by means of an electric iron. The cement is not adhesive before being heated. The rind stopping paper 22 is shown with dash lines in the figures. The unconventional construction of the trusses permits the wind stopping paper 22 of the walls and of the roof to be integral without rafters extending through the paper which reduces the risk of untightness. The wind stopping paper is cemented to the paper strips of the trusses by means of jointing tape as previously described.

[0007] Inside of the mineral wool 21, that is, on the inner side of the frame work of the walls and roof,a diffusion stopping paper 23 (the steam stop) is mounted in the same way as the rind stopping paper (the wind stop). The diffusion stopping paper 23 is shorn with dash-and-dot lines. This diffusion stopping paper 23 is tightly cemented to the paper around the raffers 15 and ties 16 by means of jointing tape 25 in the same way as previously described. The window frames and door frames and possible other frames are mounted to the frame work before the two paper layers 22,23 are mounted. In fig. 1, a window frane 24 is shown. Before the frames are mounted, a connection strip 25 of paper is attached to each frame by means of laths 27 that are nailed to the frame as shown in fig. 6. The connection strip 25 has a wide rubber sealing list that has sealing portions 28,29 on both sides of the nails. The frames are affixed to the frame work by the laths 27 that are nailed to the frame work. When the diffusion stopping paper 23 and the wind stopping paper 22 are mounted as described above, the connection strip 25 of the frame 24 is cemented to both these paper layers by means of a jointing strip 30 of the kind used also for jointing the paper strips as described. The paper of the connection strip 25 around the frame 24 has to be cut at the corners in order to permit for it to be bent against the papers 22,23, and these cuts are lapped by 'pieces of the jointing strip. A layer of diffusion stopping paper 31 is suitably put on the concrete slab 11 if an overfloor c nstruction (non-illustrated) is to be laid on the slab. A comparatively thin layer of mineral wool 32 may or may not be used in the overfloor construction above the diffusion stopping paper.

[0008] It is important that there are no leaks neither in the wind stopping layer nor in the diffusion stopping layer. Therefore, one must seal off very carefully against all elements extending through one or both stops 22,23. A pre-fabricated collar 33 of paper can be used for electric joint boxes, pipes etc. It is cemented against the diffusion stopping paper by means of a jointing strip 30 of the kind previously described and its collar 34 of crepe paper is sealed off against the box by means of a tightening band 35.

[0009] As shown in Figs. 1-3 and described above, walls and roof will be enclosed by a completely tight wind-stopping layer, the paper 22. Further, the layer of mineral wool 21 will be completely tightly 'enclosed between this wind stopping paper 22 and the diffusion stopping paper 23. The diffusion stopping paper 23 should be 10 times more diffusion stopping than the paper 22 when the construction is completely airtight as illustrated in order to avoid moisture in the mineral wool. Laths are nailed on both sides of the illustrated construction, that is, outside of the papers 22,23 and the outer and inner panel can be nailed to the latns. A sealing list of tne kind shown in fig. 6 can be placed under the laths on tne outside of the wall in order to seal off around tne nails. Tne panel need not be afiixeu to the wall construction, a more or less free standing brick wall can be used as a panel.

[0010] As described, paper is only cemented against paper. It would be possible to cement the paper 22 directly to the outside of the window frame 24 in Figs. 1-2 and cement the paper 23 directly to the inside of the frame 24. It is, however, likely that a cemented joint between paper and wood does not last as long as a cemented joint between paper and paper. It will be possible to guarantee the tightness of a joint between paper and paper for a period of 50 years if a suitable cement is used.

[0011] In fig. 4. an example is shown of the possibility of applying the invention to an existing building when the walls are insulated on their outside. In this case, there is mostly not possible to join the diffusion stop in the walls with the diffusion stop in tne roof, neither is it possible to join the wind stop in the walls with the wind stop in the roof even when walls and roof are insulated at the same time.

[0012] The additional insulation of the walls are carried out as follows

[0013] If the wall has a removable outer panel, the panel at shall first be removed. Then, diffusion stopping paper 23 is mounted on the existing wall and battens are nailed or secured in any other way to the vail. Mineral wool is now put in place to completely fill the space between the battens. Outside of the mineral wool, a wind stopping paper 22 is altached to the baltens and sealingly connected to tne difiusion paper at the end of the mineral wool at the roof and at the foundation. Further, the insulation construction is sealed off against tne existing wall by means of sealing strips as indicated with numerals 57 and 30 on Fig. 5. A sealing strip 25 of the kind shown in fig. 6 has been used at 37 and it is affixed to the existing wall by means of a nailed lath-27. The strip 25 is cemented by means of jointing strips 30 to the two paper layers 22 and 23. All joints are cemented to be tight as previously described.

[0014] At the bottom of Fig. 5, a sealing strip 39 has been used at 38. It is also shown in fig, 8 and it comprises a strip of wind stopping paper 40 to which is cemented a closed pocket 41 of crepe paper. The pocket is filled with elastic mineral wool 42 that acts as a spring to expand the pocket so that the crepe paper seals also against uneven surfaces. The sealing strip 39 at 38 in fig 5 is clamped together with a strip 43 of wind stopping paper against the existing wall by means of a nailed lath 48. The strip 43 is cemented to the layers 22 and 23 by means of jointing tape 30 in the same way as previously described so that the mineral wool insulation will be completely tightly enclosed.

[0015] In order for insulating the floor that is shown as a joist construction above a ventilated space towards the ground, the old flooring and the old insulating material is removed. Then, wind stopping paper 22 is laid in the bottom around all the joists 44 and up along the wall where an end strip 45 for instance of the kind shown in fig. 8 is used to seal against the wall. The wind stopping paper is carefully tightened in all joints by means of jointing strips as previously described. Then, the mineral wool or other insulation is placed between the joi sts and a diffusion stopping paper 23 is placed above the insulation. The paper 23 is also jointed by means of jointing strips to a completely tight layer that is jointed to the wind stopping paper by means of a jointing strip 30 as shown in fig. 5. The mineral wool of the floor will therefore also be completely tightly enclosed by the wind stopping paper 23 and the diffusion stopping paper 22.

[0016] The roof is insulated in the same way as the floor and the wind stopping paper 23 is sealed off against the wall by means of a strip 46 of the kind shown in fig. 8.

[0017] The ending strips 45 and 46 are suitably so placed as to be covered by the ceiling list and floor list respectively. In combination with the wall lining, for example wall paper, they provide an additional draft preventing layer that prevent draft through the existing wall.

[0018] An open clearance that should always be between the wind stopping layer and the roof is indicated by arrows in fig. 5 as well as in fig. 2.

[0019] In a new building with a bearing wall in a heavy construction, for example a brick wall, the insulating construction is preferably mounted on the outer side of the wall in the same way as shown in Figs. 4 and 5. The wind stopping paper of the walls and the roof should then be united in the same way as shown in Figs. 1 and 2.

[0020] In the figures, the wind stopping layer and the diffusion stopping layer has been shown as being of strong tough paper. Alternatively, hard board sheets can be used if their joints are tightened by means of jointing strips of the kind described.

Claims

1. Method of improving the thermal insulating ability of a building construction that has a layer of a thermal insulating material, wherein a diffusion stopping layer is used inside of the insulating material and a wind stopping layer is used outside of the insulating material,
characterized in that
the diffusion stopping layer as well as the wind stopping layer is cemented in its joints and that the two stopping layers are connected to completely sealingly enclose the thermal insulating layer between them.

2. Method according to claim 1, characterized in that the diffusion stopping layer or the wind stopping layer is sealed off against the building construction at the place where the respective layer begins or ends.

3. Method according to claim 1 or 2, characterized in that the two stopping layers are united by being cemented together.

4. Method according to any one of the preceding claims, characterized in that a connection strip is sealingly affixed to a frame of a window, door or the like or to the construction andthat the two stopping layers are air tight cemented to the connection strip.

5. Method according to claim 4, characterized in that a connection strip is used which comprises a sealing list that is clamped against the frame or construction.

6. Method according to claim 5, characterized in that the sealing list is clamped against the frame or construction by means of nailed laths.

7. Method according to claim 6, characterized in that a sealing list is used that has a sealing function on both sides of the nails in the lath.

8. Method according to any one of the preceding claims, characterized in that paper coated with a thermal cement and an electric iron are used for tightening joints in the layers.

9. Method according to any one of the preceding claims, characterized in that paper is used both as wind stopping layer and diffusion stopping layer.

Drawing