Field of the invention

The invention relates to an insulation piece for insulating surfaces, in particular flat roofs, low-pitched roofs or floor constructions, wherein the insulation piece is made of a mineral wool slab mat or a mineral wool slab comprising fibers as defined in the preamble of the independent claim 1.

The invention also relates to a method for insulating flat roofs, low-pitched roofs or floor constructions using an insulation piece according to claim 1 as defined in the preamble of the independent claim 6.

The invention also relates to an insulation package comprising insulation pieces according to any of claims 1 to 5 as defined in the preamble of the independent claim 11.

This invention relates to insulating low-pitched roofs or flat roofs or even floor constructions where the insulation material is mineral wool. To be precise the invention relates to insulation pieces. The mineral wool comprises fiber glass, rock wool or stone wool.

One way for insulating low-pitched roofs or flat roofs is to put on top of a supporting structure two thick layers of mineral wool and on top of those two thick layers of mineral wool one thinner layer of mineral wool. In order to cope with the constant increase in insulation need, the two thick layers are normally each about 150 - 200 mm thick and the thinner layer is about 20 - 70 mm thick. The roof has a good strain resistance and the thinner layer has a better compressive strength. These layers together form a thick enough insulation layer for low-pitched or flat roofs. The mineral wool is typically in a plate form having the width of approximately 1200 mm and the height of about 1500 mm.

A drawback with this type of insulating sheet is the amount of work that has to be done when carrying the sheets to the roof and placing them. The workers have to install three layers of insulation sheets before reaching the required insulation level which takes a lot of working time.

An insulation layer for a roof is known from EP 0 682 161 Al where the insulation layer consists of at least two type of laid strips which are laid between a roof eaves or an eaves beam and a roof ridge. The one type of strip serves to absorb the roof load introduced via base battens serving as a bearing arrangement for the roof construction and the other type of strip serves purely for insulating purposes. The one type of strip which serves to absorb the roof load is provided with far higher compression strength and of many times narrower design compared to the other type of strip which servers to insulate and which is selected to have optimum properties in respect of thermal insulating capacity. The idea of the strips that serve to absorb the roof load is to eliminate the wooden beams as supporting elements in roofs or ceilings.

The insulation layer presented in EP 0 682 161 Al serves for reducing material in typical construction work when the wooden beams as supporting elements are replaced with insulation strips. The reduced thermal insulating capacity in the region of the load-absorbing strips as is said in the description of the publication makes the insulation properties different in different parts of the roof or the ceiling while the two types of insulation strips are used. In other words the insulation is the entire area of the ceiling or the roof is not the same but some areas have poorer insulation properties than the other areas.

A roof substructure built up of insulation elements is known from DE 36

15 109 where the insulation elements have a limited size of approximately 1120 x 600 mm. The insulation system introduced in DE 36 15 109 is for steep roofs. The insulation elements comprise on the upper side of the element a laminated surface, for example a folio.

A drawback with the insulation described in DE 36 15 109 is the size of the elements. Although the size is such that a person can carry it, it is still far too big for one person to carry several at a time.

In still another way to build insulation plates, it is known to produce composite boards with increased stiffness. For instance DE 23 07 577 describes a way to cut a fiber web into lamellas, which are turned by 90° and glued together to form again a web-like product which is then cut into boards where the fibers are oriented predominantly perpendicular to the surfaces of the boards.

The size and weight of the board elements remains as a drawback with this kind of insulation. Obj ective of the invention

The object of the invention is to provide an efficient and convenient way of insulating a low-pitched roof or a flat roof or a floor construction. Another object of the invention is to provide a new type of an insulation piece. Short description of the invention

The insulation piece of the invention is characterized by the definitions of the independent claim 1.

Preferred embodiments of the insulation piece are defined in the dependent claims 2 to 5.

The method for insulating flat roofs, low-pitched roofs or floor constructions using an insulation piece the invention is correspondingly characterized by the definitions of independent claim 6.

Preferred embodiments of the method are defined in the dependent claims 7 to 10.

The insulation package of the invention is defined in the independent claim 11.

The invention introduces a new way for insulating a low-pitched roof or a flat roof. The invention can also be used on floor constructions. A low-pitched roof has a moderate slope. A roof is regarded as a low-pitched roof when it has a slope 1 : 10 or less. A flat roof is a roof being in a horizontal or almost horizontal alignment.

The insulation material according to the invention is a strip-type mineral wool piece. The piece is made from a mineral wool slab mat such that in the production line when the mineral wool is produced to the desired product thickness, thus generally after a mat of mineral wool fibers with a binder has been thermally set or "cured" and then cooled down, the slab mat is cut into slabs across the width of the production line and the slab is cut into several insulation pieces. The insulation pieces are cut such that the pieces are quite narrow but long and the cutting width can be adjusted. By way of illustration such pieces can have a ratio of length over width of at least 5 : 1 , or length over height whichever is bigger. The insulation piece is cut from the slab so that the cutting width of the insulation piece is preferably approximately 50 - 600 mm and the length of the insulation piece is preferably the same as the slab's length which is in the range of 500 mm - 2500 mm.

The fibers in a mineral wool slab mat are intertwined like a cotton candy but they generally have a certain main direction and that is the production line direction. This is because, the fibers which are produced are collected on a sucking conveyor and are laid down on the flat surface of the conveyor. At this point, a mat of mineral wool is obtained which contains fibers lying in a series of planes or surfaces, substantially parallel to the main outer surfaces (those of bigger extension) of the mat. As a result, the slab mat is quite compressible in the direction perpendicular to the main surfaces. Some steps are possible, often referred to as crimping, and used to modify the orientation of the fibers and increase the compressive strength in this direction. Nevertheless the fibers thus remain generally organized in layers, just the layers are no longer planar but become pleated or folded. As used in the present description, the main orientation of the fibers is the direction aligned with those layers of fibers. As a consequence the compressive strength of the slab mat is higher in the direction parallel to the main outer surfaces, than in the direction perpendicular to the main surfaces. By way of illustration, the compressive strength in the direction parallel to the main surfaces is about 1 ,3 to 2 times higher than the compressive strength in the direction perpendicular to the main surfaces. The insulation pieces of the invention cut out from the slab are cut the same way like normal mineral wool sheets or plates, but the pieces are narrower than normal mineral wool sheets or plates. When the pieces are used according to the invention to insulate a roof, a ceiling or a floor the pieces are used in a different way than the normal mineral wool sheets or plates.

The insulation pieces have a parallelepiped shape with two first main outer planar faces defining the intended length L and thickness T; of the installed piece, where the fibers run predominantly parallel to the surface of said planar faces, said outer planar faces being parallel and spaced by a distance defining the width Wi of the installed piece. The two first main outer planar faces are preferably the largest planar faces in the insulation piece. Those planar faces are defined by the length L of the insulation piece, which is preferably the same as the slab's length, and by the cutting width W _c of the insulation piece cut from the slab which is the same as the thickness Tj of the installed piece, said planar faces being spaced by a distance defining the production thickness T _p of the slab which is the same as the width Wi of the installed piece.

The length L of the insulation piece, which is preferably the same as the length of the slab, and width Wi of the installed piece, which is the same as the thickness T _p of the slab, define two front faces where the fibers run predominantly transverse to the planes of the front faces.

According to the invention, the pieces are such that L > Tj > Wi. Preferably the ratio L > Tj is at least 2, preferably at least 3, or even 4 or more. Preferably the ratio Tj > Wi is between 1,3 and 2,8.

The insulation piece according to the invention is in the form of an elongated piece having a first outer planar face and a second outer planar face, which the second outer planar face is in the opposite side of the insulation piece than the first outer planar face. The first and second outer planar faces are formed from the main outer surfaces of the mineral wool slab mat or a mineral wool slab from which the insulation piece is cut. The main direction of the fibers inside the insulation piece run essentially parallel to said first and second outer planar faces of the insulation piece. The insulation piece is an elongated piece, such that when the insulation piece is cut from the mineral wool slab mat or mineral wool slab, the ratio of length L to width W _c is at least 3 : 1, preferably 5 : 1.

By way of illustration, the compressive strength in the direction perpendicular to the front faces is about 1 ,3 to 2 times higher than the compressive strength in the direction perpendicular to the main outer planar faces. For instance, it can be about 50 kPa in the direction perpendicular to the front faces versus 30 kPa in the direction perpendicular to the main outer planar faces for a glass wool piece of the invention.

Thus preferably a slab is formed by cutting a slab mat across the width of the production line and the slab is then cut into insulation pieces along the production line. The cuts can be carried-out on line, or the slabs can be stored and sent to a transformation place where they are cut into pieces on demand.

The pieces are then put together in a package. Preferably they are arranged side by side, laying on one of their front face with the main outer planar face of a piece contacting the main outer planar face of the next piece. The group of pieces is enclosed in a packaging film, without any glue to attach the pieces together, and they may be together under compression, and a number of groups can be stacked on a pallet support and further enclosed in a protective wrapping foil. The insulation package comprises insulation pieces such that the insulation pieces are laid next to each other with one first or second outer planar face of a piece contacting a first or second outer planar face of the next insulation piece and the insulation pieces are included in a packaging film.

The pieces are laid on top of the supporting structure which has, if needed, other layers such as vapour barrier and/or smoothing concrete laid to a layer between the supporting structure and the insulation layer. The pieces are laid on one of their front face, such that they are turned 90 ⁰ in longitudinal direction from original mat, so that the main outer planar faces of the piece, formerly top side and bottom side of the mat, are now side parts facing to the next piece laid next to the previous piece. The main fiber orientation is now turned 90 ⁰ from the typical fiber orientation in a normal insulation sheet, therefore mainly vertical. The thickness of the mineral wool slab mat now determines the width of the piece which is in the range of 50 - 600 mm, preferably 200 - 250 mm.

The insulation piece is arranged to the surface to be insulated such that the main fiber orientation inside the insulation piece is essentially perpendicular to the surface to be insulated. The surface to be insulated is essentially in a horizontal plane, such as a horizontal floor or almost horizontal roof, such as a low-pitched roof with roof pitch at the maximum 1 :10 and at the minimum 1 :80 and preferably 1 :40. The insulation piece is preferably turned 90° in a longitudinal direction before arranging it to the surface to be insulated. One or more other layers can be arranged between the supporting structure and the layer of insulation pieces. The insulation pieces are arranged next to each other to form a square after which same amount of insulation pieces are arranged in a direction 90 ⁰ from the earlier direction to form another square. The insulation piece has a first outer planar face and a second outer planar face and the first outer planar face of an insulation piece is arranged next to the second outer planar face of the next insulation piece.

The pieces are preferably laid such that several pieces, e.g. 6 - 8 pieces, are laid next to each other and then the next same amount of pieces are laid in a direction of 90 ⁰ to the other direction and so on so that the pattern of the pieces laid next to each other will look like a checker board pattern. The number of pieces laid next to each other depends on the length L and width Wi of the installed piece, the width Wi of the installed piece coming from the thickness T _p of the slab and originally from the slab mat. For example if the length L of the piece is 1575 mm and the width Wi of the installed piece is 225 mm then 7 pieces are to be put next to each other in the same direction. The pieces can also be set in other formation than the checker board pattern; the pieces can be set for example imbricated.

Another way arranging insulation pieces to the surface to be insulated is to put them in the same way as bricks are placed when the bonding of bricks is used. This means that all the insulation pieces are not put to start at the same place but imbricated so that the same pattern as in brick walls is achieved..

While the covering coming on top of the insulation pieces, such as a water proof membrane, is attached to the supporting structure, for example by means of fastening screws drilled through the covering and insulation layer, the set of insulation pieces is at the same time attached to it. Pieces can also be attached temporarily if needed and glue may also be used for attaching them on the roof until receiving the covering.

If the roof structure or floor structure that will have the pieces above it has any obstacles, it is easy to make adjustments to the pieces because of the size of the piece. That way the amount of waste coming from insulation in the construction site can be minimized as well. Above the ready made piece structure a thin layer of mineral wool can be set if needed. When the insulation layer is put to the roof a water proof membrane layer will be set above the insulation layer. When having the insulation layer inside the floor structure, there can be for example concrete or casting above it.

The invention is meant for roofs or floors that are in a horizontal or almost horizontal plane. Almost horizontal plane means that the roof pitch is at the maximum 1 : 10. Preferably the roof pitch in a low-pitched roof is 1 :40 and typically the minimum roof pitch for low-pitched roof is 1 :80. This all applies for floor constructions as well if needed for some purpose.

The benefits of the invention are that the insulation layer is quicker ready, there will be at a maximum two type of mineral wool pieces and one type of insulation pieces in one layer. The insulation pieces have better load resistance, because the fiber structure is vertical. Also the ergonomic aspects in the construction side are important since the pieces are easy to carry because of the size and weight. The benefit of the invention is also that when producing the insulation pieces from fiberglass the consumption of the raw material is less than when producing insulation sheets since the insulation pieces are made having a density between 40 - 80 kg/m and preferably about 40 - 60 kg/m while the normal insulation sheet have a density of 60 - 100 kg/m ^J . The same applies when the insulation pieces are produced from rock wool or stone wool although the density of the rock wool is bigger but the benefit is still that the consumption of the raw material is less than when producing insulation sheets, namely the density of a normal slab of stone wool insulation would

3 3

be around 110 kg/m , and can be reduced to 70-80 kg/m with pieces of the invention. List of figures

In the following the invention will be described in more detail by referring to the figures, in which figure 1 shows a prior art insulation above a roof supporting structure, figure 2 shows a mineral wool slab and a cut insulation piece according to the invention, figure 3 shows an insulation above the roof supporting structure according to the invention, and figure 4 shows one way of setting insulation pieces to the mounting surface.

Detailed description of the invention

The figure 1 is a cross-section of an insulated roof structure and shows a prior art way of insulating a roof such that the insulation sheets 4.1 , 4.2 are laid above a roof supporting structure 1. The roof in this example is a flat roof and as a supporting structure 1 is a hollow-core concrete slab. Above the supporting structure 1 is in this example a smoothing concrete layer 2. Above the smoothing concrete layer 2 is a vapor barrier 3, for example an insulation membrane. Above the vapor barrier 3 are two insulation sheets 4.1 , 4.2 in two layers which are laid as usual one above the other. Each insulation sheet 4.1, 4.2 is about 150 - 200 mm thick and preferably 200 mm thick so that they form together about 400 mm thick insulation level above the roof supporting structure 1. The pattern inside the insulation sheet 4.1 , 4.2 reflects the alignment of the insulation sheet 4.1, 4.2 such that the top part 9a of the pattern inside the insulation sheet 4.1, 4.2 reflects the top side of the mineral wool slab mat from which the insulation sheet 4.1, 4.2 was cut and the bottom part 9b of the pattern inside the insulation sheet 4.1 , 4.2 reflects the bottom side of the mineral wool slab mat from which the insulation sheet 4.1, 4.2 was cut. Fibers inside the insulation sheets 4.1, 4.2 have a main direction which in this figure is perpendicular to the cross section, i.e. in the same direction as the pattern ridge. Above the two layers of insulation sheets 4.1 , 4.2 is a thin insulation sheet 5 which is about 50 mm thick and is there to form a good strain resistance layer. On top of all the layers is a water proof roof membrane layer 6.

The figure 2 is a partial view of a production line and shows the end of a production line where a mineral wool slab 8 is formed by cutting the slab mat across the width of the production line and the slab 8 is cut into insulation pieces 7. The part of the production line which is not shown includes a fiberizing chamber where the mineral wool fibers are produced and sprayed with a binder, and the binder sprayed fibers are collected on a foraminated conveyor in the form of a mineral wool mat, which goes through a curing oven where the binder is thermally set so as to give the final shape of the mineral wool slab mat. A piece of the slab mat, i.e. a slab 8, is then cut after the mat has cooled down, with an appropriate cutting tool across the full width of the production line. The lines showing a pattern on the front face of the slab 8 visible along the cut line reflects the alignment of the slab 8 such that the top part 9a of the pattern is there to point out the top side of the slab 8 and the bottom part 9b of the pattern is to point out the bottom part of the slab 8. The same goes for the insulation piece 7 where the top part 9a of the pattern is to point out the former top part of the insulation slab 8 which now forms main first outer planar face 7a of the piece 7 and the bottom part 9b of the pattern is to point out the former bottom part of the insulation slab 8, which now forms main second outer planar face 7b of the piece 7. The insulation pieces 7 are cut from the mineral wool slab 8 into strip-like insulation pieces 7 that are narrow but long. The main fiber orientation, i.e. the main fiber direction, is the same direction as the production line direction. In the insulation piece 7 the main fiber orientation is the not in the longitudinal direction of the insulation piece 7 but the transverse direction during the time when the piece is cut but not turned to the mounting position. In the mounting position the main fiber orientation is vertical.

So when the insulation pieces 7 are cut from the mineral wool slab 8 the cut width W _c of the insulation piece 7 will define the thickness of the insulation layer, i.e. the thickness T; of the insulation piece 7 when installed, i.e. when the insulation piece is arranged to the mounting position not like when compared to the prior art sheets where the width of the sheet actually defined the width of the insulation sheet nothing else. In other words the cutting width W _c of the insulation piece 7 is the same as the thickness Tj of the installed insulation piece 7. The insulation pieces 7 are according to the invention cut from the mineral wool slab 8 preferably approximately 50 - 600 mm wide, but in this example the pieces are cut preferably 350 - 450 mm wide so that one insulation piece 7 makes the full or almost full thickness of the insulation layer. The width of the insulation piece 7 as laid to the roof surface, i.e. the width Wi of the installed piece 7, is the thickness T _p of the original mineral wool slab before cut to insulation pieces 7 and it varies in the range of 50 - 500 mm. The length L of the insulation piece 7 is the same as the length L of the slab 8.

The figure 3 is a cross-section of an insulated roof structure and shows the insulation piece 7 according to the invention which is laid above the roof supporting structure 1. In this example the roof is a flat roof and the supporting structure 1 is a hollow-core concrete slab as in the figure 1 when examining the prior art insulation. Other supporting structures 1 are of course possible too. The roof type can vary inside the scope of the invention and it can be for example a low-pitched roof as well. Using the insulation piece 7 above a supporting structure 1 is not limited to a hollow-core concrete slab supporting structure 1 but instead whatever supporting structure 1 that is suitable for a flat roof or a low-pitched roof can be used together with the insulation piece 7 according to the invention. A smoothing concrete layer 2 is applied on top of the supporting structure 1. The smoothing concrete layer 2 is not obligatory and it is not always needed so in those cases when it is not needed it can be left out. On top of the smoothing concrete layer 2 is a vapor barrier 3. The insulation piece 7 according to the invention is laid above the vapor barrier 3 such that the insulation pieces 7 are put next to each other. In this figure there are four insulation pieces 7 shown which are arranged next to each other. The insulation layer comprises preferably only one type of thick insulation pieces 7 laid next to each other such that the width Wi of the insulation piece 7 as installed is the former thickness T _p of the slab 8 during the production line phase. Now the thickness T; of the installed piece is the same as the cutting width W _c of the insulation piece 7 in the end of the production line as shown in figure 2. The length L of the installed piece 7 is the same as the length of the slab 8. Above the thick insulation piece 7 layer is preferably a thin insulation piece 5 layer and above the thin insulation piece 5 layer is a water proof roof membrane layer 6, such as a rubberized bitumen layer.

The figure 4 is a view from above the insulation layer made of insulation pieces 7 and shows one example of arranging insulation pieces 7 next to each other to form an insulation layer. As earlier explained the insulation piece 7 is cut in the end of the production line from a slab 8 and the cutting width W _c is the same as the thickness Tj of the installed insulation piece 7 (this is not shown in this figure). The thickness T _p of the slab 8 during the production phase is the same as the width Wi of the installed insulation piece 7. The main orientation of the fibers in the slab mat during the production line phase is generally parallel as the layers of the insulation slab mat forming the thickness of the slab mat. Now when the insulation piece 7 is installed and the width Wi of the installed insulation piece 7 is the same as the thickness T _p of the slab 8 the main fiber orientation in the installed insulation piece 7 is perpendicular or substantially perpendicular to the roof supporting structure. The insulation piece 7 as installed has a first outer planar face 7a and a second outer planar face 7b which are a result from the production line phase where the first outer planar face 7a is a top side 9a of the mineral wool slab 8 and the second outer planar face 7b is the bottom side 9b of the mineral wool slab 8 before being cut into insulation pieces 7. The width Wi of the insulation piece 7 as laid to the roof surface is the thickness T _p of the original mineral wool slab 8 before cut to insulation pieces 7 and it varies in the range of 50 - 500 mm.

The pieces 7 are laid to the insulation layer such that the first outer planar face 7a of an insulation piece 7 is put next to a second outer planar face 7b of the next insulation piece 7 or the first outer planar face 7a of an insulation piece 7 is put next to a first outer planar face 7a of the next insulation piece 7. The pieces 7 can be laid such that they form a checker board pattern like in figure 3 or they can be laid differently such as imbricated or otherwise.

The insulation piece 7 is used for insulating a horizontal surface and or the insulation piece 7 is used for insulating a almost horizontal surface having a pitch at a maximum 1 : 10, preferably 1 :40 and at a minimum 1 :10.

It is apparent to a person skilled in the art that as technology advanced, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.