METHOD FOR THE MAKING OF SELF-PLUGGING AND/OR NON-DRIPPING ROOFING CONSTRUCTION

Abstract: In order to make a roofing construction leak proof it is provided with a layer containing hydrophilic polymers and/or known inorganic viscosity-increasing and/or gel-forming hydrophilic substances. The layer may be incorporated the construction in the form of a membrane or a coating or it may be distributed as a powder. Due to this layer the roofing construction will become self-plugging.

Description: Method for the making of self-plugging and/or non-dripping roofing construction. The invention relates to the making of self-plugging and/or non-dripping roofing construction. A modern roof design normally includes a structure to carry loads, insulation to control heat flow, a barrier to control air and vapour flow, and a roofing element to prevent water penetration. Problems connected with leaks and dripping are known to occur with more or less all types of roofs, but are more prevalent with some roof designs than with others. There are such factors as roof angle, type of insulation or no insulation, type of roofing material and obviously the climate outside and inside which have significant bearing on the tendency for leaks and dripping from condensation of a particular building. Buildings with flat or low-angle roofs in climates with snow during winter or with heavy rains and high humidity are particularly prone to develop leaks. Industrial buildings with a production process entailing high humidity are particularly prone to dripping from condensation. On buildings with flat low-angle the roofs socalled "built-up roofing" is the most common roofing type used. Built-up roofing is a continous membrane covering manufactures on site from alternate layers of bitumen, bitumen-saturated felts or asphalt-impregnated glass mats, saturated and coated felts, and surfacings. New materials have " lately led to roofing materials of single-ply or limited-ply membranes consisting of e.g. a single-ply sheet of an ealstomeric or plastic material. Roofing membranes can also be liquid-applied as a single or two-component system with polymeric fabrics or glass-fibre reinforments. « hatever the type of roof and roofing construction and material used, water leaks and condensation can occur, particu¬ larly in the spring in cold climates when the snow on the roof 2MPI is melting, or during so heavy rain falls that the roof-gutters cannot cope with the amount of water on the roof. Water leakage and dripping for roofing constructions can have considerable economic consequences, even when the amount of water is small, for instance because the leakage site is of very small size, perhaps only a small nail hole. It is also extremely difficult to locate such leakage sites, the more dif¬ ficult the smaller the leak. Similar problems can also be caused by condensation as a result of not sufficiently effective insulation or ventilation. The object of the invention is to solve the above mentioned problems and to provide a method which makes it pos¬ sible to achieve a self-plugging, i.e. a self acting leak-stop¬ ping and/or non-dripping roofing construction. This object is achieved by a method in which a layer is incorporated in the roofing construction, which layer contains hydrophilic polymers and/or known inorganic viscosity- increasing and/or gel-forming hydrophilic substances. The invention also relates to a roofing construction provided with a layer of the above type. " The present invention solves these problems in a simple and economic way by making use of the special properties which hydrophilic polymers and/or certain hydrophilic inorganic sub¬ stances possess for increasing the viscosity of water to such an extent that it will not drip from the roofing construction, and/or to bind the water in the form and consistency of a gel. Such polymers and inorganic substances can also by water be brought to swell to such an extent that a leakage is stopped by itself. The hydrophilic polymers which can be used with the method, can either be water-soluble or water-swellable, or a combination of both. The same applies for the inorganic subs¬ tances. Water-soluble polymers and/or water-soluble inorganic substances of the mention type can be made non water-soluble through partial cross-linking, i.e. cross-linking which leaves a number of hydrophilic groups free to bind water molecules. The hydrophilic polymers and/or inorganic hydrophfeic sub¬ stances can be incorporated in many different ways in the OMP roofing construction: 1) either be applied to the deck as a coating, or 2) applied as a coat on the overside or the underside of the membrane, e.g. organic felt, asbestos ply felt, fiber-glass mats or base sheets, shingles, elastomeric or plastic film and sheeting etc. , or on another component of the roofing construc¬ tion, or 3) in the form of a film, sheet, mat, loose powder etc. be laid out over or under another component of the roofing con¬ struction, or ' 4) be incorporated in the membrane whatever the type, e.g. in a felt or sheet, or 5) be applied on or in other ways attached to other compo¬ nents which are part of the roofing construction. As an example of hydrophilic polymers which can be used for the method can be mentioned natural hydrophilic polymers such as gum arabic, traganth and karaya, semi-synthetic hydro¬ philic polymers such as carboxymethylcellulose, methylcellulose and other cellulose ether ' s, lignin derivates, various kinds of modified starches (ethers and acetates), and synthetic hydro¬ philic polymers such as polyacrylic acids, polyacrylamides, and polyethylenoxide, polyvinyl pyrrolidone, polyethylenimine and others, as well as combinations of such polymers or with other substances. As examples of inorganic substances, which can either be used alone to bind water in the form of a gel or a highly vis¬ cous fluid, can be mentioned water glass, alumina, magnesia, betonite etc. and mixtures of such inorganic hydrophilic sub¬ stances or mixtures of these and hydrophilic polymers. The mentioned hydrophilic polymers and/or hydrophilic inorganic substances can eventually be cross-linked, either in the form of a pre-crosslinked film or sheet or similar or a layer cross-linked in situ. As an example of the former can be mentioned "Dow Water Absorbent Laminate" and of the latter a mixture of lignosulfonate and dichromate. • There is an extensive patent and other literature treating viscosity-increasing or gel-forming polymers and inorganic substances, particularly within the fields of grouting and oil drilling . The may be major part of such polymers and inorganic substances could f ind application with the method of the pre¬ sent invention with the necessary adjustments .

Claims: P a t n t C l a i m s 1. Method for making of self-plugging and/or non-dripping roofing construction, c h a r a c t e r i z e d in h a t a layer is incorporated in the roofing construction which contains hydrophilic polymers and/or known inorganic vis¬ cosity-increasing and/or gel-forming hydrophilic substances. 2. Method in accordance with claim 1, c h a r a c t e ¬ r i z e d i n t h a t the hydrophilic layer is in the form of a membrane or similar. 3. Method in accrodance with claim 1, c h a r a c t e ¬ r i z e d i n t h a t the hydrophilic layer is in the form of a coat on another component of the roofing construc¬ tion. 4. Method in accrodance with claim 1, c h a r a c t e ¬ r i z e d i n t h a t the layer is distributed onto the roofing construction in the form of a powder. 5. .Roofing construction c h a r a c t e r i z e d b y a layer containing hydrophilic polymers and/or known inorganic viscosity-increasing and/or gel-forming hydrophilic substances.

Inventors: RASMUSSEN OEYSTEIN E, RASMUSSEN, OEYSTEIN, E.
Applicants: RASMUSSEN OEYSTEIN, RASMUSSEN, OEYSTEIN, E.
Application year: 1984
Main classification: C09K3
IPC codes: E04D7, E04D11, E04D13