Damp-proofing and/or corrosion-protecting membrane for building structures

Abstract: A method of producing a damp-proofing and/or corrosion-protecting membrane (M) on building structures (1), such as roofs, bridges or pipelines, and where the membrane comprises at least one material layer (2, 4). A layer of cold flow, damp-proofing and/or corrosion-protecting, reaction-setting, bitumen-based adhesive mixture (3) is layed in situ on a first material layer (2) already placed on the building structure (1), optionally merely directly on the building structure, said layer of adhesive mixture being layed in a thickness ( t ) corresponding to 10 to 80% of the total thickness ( d ) of the membrane (M). The latter thickness is in the range of 2 to 16 mm, and the adhesive mixture (3) is of a thick pasty consistency. Before the adhesive layer has set, a second material layer (4) is subsequently layed on the top side of said adhesive layer (3). As a result, the security risks are reduced as well as it is possible to improve the working environment in connection with the production in situ of the membrane, i.e. a reduced release of possible injurious vapours or fumes is provided. In addition, the membrane is very resilient and resistant to formation of cracks.

Description: A method of producing a damp-proofing and/or corrosion-protecting membrane on building structures, such as on roofs, bridges or pipelines, said membrane comprising at least a first material layer of for instance roof felt, a layer of cold flow, damp-proofing and/or corrosion-protecting, reaction-setting, bitumen-based adhesive mixture placed in situ on the first material layer and a second material layer placed on top of the layer of adhesive mixture prior to the setting of the latter, the layer of adhesive mixture being of a thick pasty consistancy as it is laid. A stripe-shaped covering material is known for the production of joints or sealings and which can form a resistant layer on the outside of building structures. The covering material comprises a coating layer and an "adhesive layer" applied thereon. The adhesive layer is formed by a structure layer, such as of woven fabric, impregnated with reactive bitumen-based adhesive. During the production on a factory, the covering material is subjected to a drying at 30 to 90°C. The ready-made covering material is stored on rolls and kept dry. When the covering material is to be layed out, the roll of covering material is transported to the building structure to be coated, and the bottom side of the covering material is subsequently coated with an activating agent or provided with the second component of a two-component adhesive. As an alternative, the covering material can be subjected to heat. In other words and unlike the present invention, a ready-made, cold flow, damp-proofing adhesive layer is not layed in situ on the building structure to be coated. The production of the known covering material is encumbered with the draw-back that the vapours resulting from the drying of the adhesive at the factory may cause environmental problems. In any case the vapours are very injurious to the persons carrying out the various operations involved in the production of the covering material. It is also known to produce a damp proof of the above type, which necessitates the use of open fire, which in turn involves considerable environmental problems and unnecessary risks. US-A-4 820 578 discloses a damp-proofing and corrosion-protecting membrane on building structures. The membrane consists of one material layer (a non-woven material of polyketone) on top of which a layer of corrosion-protecting, reaction-setting, bitumen-based adhesive mixture (hot-mopped asphalt) is placed (in situ). While being placed, the adhesive mixture is of a thick pasty consistancy. On top of the adhesive mixture, a second material layer is laid prior to the setting of the latter. As adhesive mixture it is inter alia suggested to use hot bitumen composed of at least 85-95 wt% asphalt and 15-5 wt% of a SEBS (styrene-epoxy-butadiene-styrene) rubber. The adhesive mixture may also contain toluene. The object of the present invention is to provide a method of producing a membrane of the above type which reduces the security risks and ensures an improved working environment in connection with the in situ production of the membrane, i.e. avoids the release of possible injurious vapours or fumes, and which in addition is particularly resilient so as to resist formation of cracks. The method according to the invention is characterised in the features mentioned in the characterising clause of claim 1. As a result, a membrane is obtained which is very lenient to the working environment because when it is laid it will give no rise to injurious vapours from the adhesive applied onto said material layer. The adhesive mixture is often considered the most injurious matter, but the inventive adhesive mixture will not give off vapours of any significance. Solvents have been completely avoided and the remaining components are only very slowly volatile, if volatile at all. As open fire is not used either, no injurious fumes are released. The provided efficient adhering ensures that the ready-made membrane is free of bulges and blisters. In addition, the membrane is very resilient and resistant to cracks and weather conditions. According to the invention the adhesive mixture may in addition to bitumen comprise blocked bitumen-compatible polyol compounds and a reaction-initiating component in form of polyisocyanate compounds or polyisocyanate prepolymers, which results in a particularly advantageous embodiment of the membrane. It is advantageous when, according to the invention, the adhesive mixture in addition to bitumen also comprises blocked polyisocyanate compounds or polyisocyanate prepolymers and a reaction-initiating component in form of bitumen-compatible polyoles. A further advantageous embodiment of the method according to the invention is characterised in that in addition to bitumen the adhesive mixture comprises blocked polyisocyanate and/or blocked amines and/or blocked amine compounds, such as ketimines or alkanol amines with α-β-unsaturated carbonyl compounds, and bitumen-compatible polyisocyanate compounds or polyisocyanate prepolymers or epoxy and/or epoxypolyurethane compounds as reaction-initiating component. Moreover according to the invention the second material layer may on its bottom side be provided with a reinforcement preferably made of woven or felted bitumen-compatible products, such as polyester tissue, possessing a high resistance to weather effects, and the reinforcement may optionally be impregnated with the same material as the material of the second material layer. As a result the ready-made membrane possesses an improved strength and resistance to weather effects. Furthermore according to the invention the first material layer may on its top be provided with a second reinforcement preferably made of woven or felted bitumen-compatible products, such as polyester tissue, possessing a high resistance to weather effects, and the reinforcement may optionally be impregnated with the same material as the material of the second material layer. In this manner it is ensured that the ready-made membrane is additionally strengthened and resistant to weather effects. According to the invention the first material layer may be constituted by an old covering material, such as roof felt, placed a long time ago on the structure where the membrane is to be produced with the result that the membrane according to the invention is particularly lenient to the environment as the old roof felt is reused instead of being discarded and taking up room on a dumping ground. According to the invention the adhesive mixture may be layed out in a thickness of 30 to 70% of the total thickness of the membrane, whereby the membrane is suitably strong without requiring much material. Moreover according to the invention the adhesive mixture may be layed in a thickness of 45 to 55%, preferably approximately 50%, of the total thickness of the membrane, which turned out to be particularly advantageous in practice. According to the invention the total thickness of the membrane may be in the range of 6 to 11 mm, preferably 5 to 10 mm and especially 8 mm. Further, according to the invention the first material layer and the second material layer are advantageously made of bitumen such as styrene-butadiene-styrene modified bitumen or oxide bitumen. Finally, according to the invention said "one material layer" is advantageously avoided and the layer of adhesive mixture is placed directly on the building structure. The invention is described below with reference to the accompanying drawing, in which Figure 1 is a vertical sectional view of a damp-proofing and/or corrosion-protecting membrane according to the invention, Figure 2 is a cross-sectional view of an embodiment of the membrane, where the layer of adhesive mixture is layed directly on the building structure, Figure 3 illustrates a membrane corresponding to Figure 1, but whereby the second material layer has been provided with a reinforcement on its bottom side, Figure 4 illustrates a membrane corresponding to Figure 1, but whereby the first material layer has been provided with a reinforcement on its top side, Figure 5 illustrates a membrane corresponding to Figure 1, but whereby both the top side of the first material layer and the bottom side of the second material layer have been provided with a reinforcement, and Figure 6 illustrates a membrane corresponding to Figure 2, but whereby the second material layer has been provided with a reinforcement on its bottom side. The membrane M shown Figure 1 is produced by a first material layer 2 in form of for instance roof felt being layed out on a portion of a building structure 1, such as for instance a roof, a bridge or a pipeline. The first material layer may be in form of many other materials too. The material layer 2 is applied in a conventional manner either mechanically or by means of adhesive onto the building structure. A layer of cold flow, damp-proofing and/or corrosion-protecting, reaction-setting bitumen-based adhesive mixture 3 is layed in situ directly on the first material layer 2. The adhesive mixture 3 is of a thickness t corresponding to 10 to 80% of the total thickness d of the membrane M, the latter thickness being in the range of from 2 to 16 mm. The adhesive mixture is of a thick to pasty consistency. Subsequently, a second material layer 4 is layed directly on the layer 3 of adhesive mixture 3, said second material layer for instance also being made of roof felt. The second material layer 4 must be layed out before the layer 3 has set. As illustrated in Figure 2, the first material layer 2 may be omitted. It is possible to lay the layer of adhesive mixture directly on the building structure 1 and then lay the second material layer 4. The adhesive mixture used for the layer 3 comprises at least one reaction-initiating component being added to the adhesive mixture before the latter is to be layed out. The adhesive mixture may for instance comprise 63.7% by weight of bitumen and 33.5% by weight of hydroxyl-terminated polybutadiene of an average molecular weight of 2000 to 6000 as well as 2.7% by weight of polydiphenylmethane-4,4-diisocyanate as reaction-initiating component. The layer 3 is never subjected to a flame because such a procedure may cause an injurious formation of fumes. However, assisting heat may be provided by means of electric heaters, such as an electric heat carpet, being moved around on the structure. The adhesive mixture 3 can in addition to bitumen also comprise blocked bitumen-compatible polyol compounds and a reaction-initiating component in form of polyisocyanate compounds or polyisocyanate prepolymers. It is also possible that the used adhesive mixture 3 in addition to bitumen can comprise blocked polyisocyanate compounds or polyisocyanate prepolymers and a reaction-initiating component in form of bitumen-compatible polyoles. In order to control the setting time which can last from minutes to hours, it is furthermore advantageous that the used adhesive mixture in addition to bitumen can comprise both blocked polyisocyanates and/or blocked amines or blocked amine compounds, such as ketimines or alkanol amines with α-β-unsaturated carbonyl compounds, and bitumen-compatible polyisocyanate compounds or polyisocyanate prepolymers or epoxy and/or epoxypolyurethane compounds as reaction-initiating component. The adhesive mixture comprises for instance 11.1% by weight of bitumen, 10.0% by weight of ketimine, 11.1% by weight of process oil, 1.1% by weight of accelerator, and 44.5% by weight of blocked polyisocyanate together with 22.2% by weight of unmodified epoxy resin as reaction-initiating component. As illustrated in Figure 3, the second material layer 4 can on its bottom side be provided with a reinforcement 5 a , preferably of woven or felted bitumen-compatible products, such as polyester tissue, possessing a high resistance to weather effects. Figure 4 illustrates how the first material layer 2 can be provided on its top side with a second reinforcement 5 b , preferably of woven or felted bitumen-compatible products, which like the reinforcement 5 a is preferably made of polyester tissue possessing a high resistance to weather effects. Figure 5 illustrates how both the second material layer 4 and the first material layer 2 can be provided with reinforcements 5 a and 5 b . These reinforcements are preferably also of polyester tissue. Figure 6 illustrates how the bottom side of the second material layer 4 can be provided with a reinforcement 5 a . In the modifications of the membrane M illustrated in Figures 1, 3, 4, and 5, the first material layer 2 can be an old roof felt layed a long time ago on the building structure 1. Accordingly, the old roof felt is thereby reused. The layer 3 of adhesive mixture is preferably layed out in a thickness t of 30 to 70% of the total thickness d of the membrane M, especially in a thickness t of 45 to 55% of d , and particularly preferred in a thickness t of approximately 50% of d . The total thickness d of the membrane M is advantageously in the range 6 to 11 mm, preferably 5 to 10 mm, and especially 8 mm. The material layer 2 can comprise 1 to 4 mm of SBS bitumen, on top of which polyester felt of a % by weight of 60 to 250 g/m² can be placed as reinforcement 5 b . The material layer 4 can comprise 1 to 6 mm SBS bitumen, below which a reinforcement 5 b of a % by weight of 60 to 250 g/m² can be provided. The reinforcements 5 a and 5 b may optionally be impregnated with the bitumen of the layers 2 and 4. The second material layer 4 can be provided with minerals strewn on its top side. The term "reaction-setting" refers both to chemical and to physical processes.

Claims: A method of producing a damp-proofing and/or corrosion-protecting membrane (M) on building structures (1), such as roofs, bridges or pipelines, said membrane comprising at least one material layer (2, 4) of for instance roof felt, a layer of cold flow, damp-proofing and/or corrosion-protecting, reaction-setting, bitumen-based adhesive mixture (3) placed in situ on the first material layer (2), and a second material layer (4) placed on top of the layer (3) of adhesive mixture prior to the setting of the latter, the layer of adhesive mixture being of a thick pasty consistancy as it is laid, characterised in that the layer of adhesive mixture (3) has a thickness ( t ) corresponding to 10 to 80% of the total thickness ( d ) of the membrane (M), the latter thickness being in the range of 2 to 16 mm, the adhesive mixture (3) further comprising at least one blocked component X and at least one reaction-initiating component Y, the latter being added to the adhesive mixture just before the latter is to be layed out, X being selected from the group consisting of blocked bitumen-compatible polyol compounds, blocked polyisocyanate compounds, blocked polyisocyanate prepolymers, blocked polyisocyanates, blocked amines, blocked amine compounds, and mixtures thereof, and Y being selected from a group consisting of polyisocyanate compounds, polyisocyanate prepolymers, bitumen-compatible polyoles, bitumen-compatible polyisocyanate compounds, bitumen-compatible polyisocyanate prepolymers, bitumen-compatible epoxy compounds, bitumen-compatible epoxy polyurethane compounds, and mixtures thereof. A method as claimed in claim 1, characterised in that the blocked component of the adhesive mixture (3) comprises blocked bitumen-compatible polyol compounds and that the reaction-initiating component of the adhesive mixture comprises polyisocyanate compounds or polyisocyanate prepolymers. A method as claimed in claim 1, characterised in that the blocked component of the adhesive mixture (3) comprises blocked polyisocyanate compounds or polyisocyanate prepolymers and that the reaction-initiating component comprises bitumen-compatible polyoles. A method as claimed in claim 1, characterised in that the blocked component of the adhesive mixture (3) comprises blocked polyisocyanate and/or blocked amines and/or blocked amine compounds, such as ketimines or alkanol amines with α-β-unsaturated carbonyl compounds, and that the reaction-initiating component comprises bitumen-compatible polyisocyanate compounds or polyisocyanate prepolymers or epoxy and/or epoxypolyurethane compounds. A method as claimed in claim 1, characterised in that the second material layer (4) is provided on its bottom side with a reinforcement (5 a ) preferably made of woven or felted bitumen-compatible products, such as polyester tissue, possessing a high resistance to weather effects, and that the reinforcement has optionally been impregnated with the same material as the material of the second material layer (2). A method as claimed in claim 1, characterised in that the first material layer (2) is provided on its top side with a second reinforcement (5 b ) preferably made of woven or felted bitumen-compatible products, such as polyester tissue, possessing a high resistance to weather effects, and that the reinforcement has optionally been impregnated with the same material as the material of the second material layer. A method as claimed in claim 1 or 6, characterised in that the first material layer (2) is constituted by an old covering material, such as roof felt, used for a long time on the structure where the membrane is to be produced. A method as claimed in one or more of the preceding claims 1 to 7, characterised in that the adhesive mixture (3) has a thickness ( t ) of 30 to 70% of the total thickness ( d ) of the membrane. A method as claimed in one or more of the preceding claims 1 to 8, characterised in that the adhesive mixture (3) has a thickness ( t ) of 45 to 55%, preferably approximately 50%, of the total thickness ( d ) of the membrane. A method as claimed in one or more of the preceding claims 1 to 9, characterised in that the total thickness ( d ) of the membrane is in the range of 6 to 11 mm, preferably 5 to 10 mm, and especially 8 mm. A method as claimed in one or more of the preceding claims 1 to 10, characterised in that the first material layer (2) and the second material layer (4) are made of bitumen, such as styrene-butadiene-styrene modified bitumen or oxide bitumen. A method as claimed in one or more of the preceding claims 1 to 11 characterised in that said "one material layer" is avoided and the layer of adhesive mixture is placed directly on the building structure.

Inventors: HANSEN PELLE J, JESSEN ERLING, JORGENSEN HANS ERIK, HANSEN, PELLE J., JESSEN, ERLING, JORGENSEN, HANS ERIK
Applicants: PHONIX CONTRACTORS AS, AS PHONIX CONTRACTORS
Application year: 1991
Main classification: E04D7
IPC codes: F16L58, E04D7, E04D11