US1925214A - Method for waterproofing - Google Patents

Description

Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE No Drawing. Application July 3, 1930 erial No. 465,792

1 Claim.

This invention relates to waterproofing, and particularly to the application of a layer of waterproofing or dampproofing material on build- 5 ing structures such as walls, partitions and the like.

The object of the invention is to provide a method for applying waterproofing material, such as asphalt, tar or the like, effectively and expeditiously, so as to give a very tenacious and 30 durable bond between the waterproofing material and the surface to which it is applied.

A further object of the invention is to provide a method whereby the waterproofing material may be applied in heated condition as a spray formed, for instance, by air from an air gun or the like projecting the hot material against the surface in divided form and at high velocities.

The waterproofing medium is preferably asphalt but may be tar or other waterproofing medium adapted to be applied in liquid form and to harden or solidify after application to the surface to be waterproof. The asphalt is of the semi-mastic type out back with asoftening agent, preferably volatilizing on exposure so that the applied asphalt will tend to harden in place.

For many purposes I prefer to mix the waterproofing medium, asbestos fibres or other filler to add to the body of the applied material, the

fibres being of medium length and applied in proportions of lbs. of asbestos fibre to 50 gallons of asphalt although these proportions may be widely varied. The asphalt or mixture of asphalt and asbestos or the like is supplied from a container, air pressure being applied to force the material through a pipe or hose to the air gun. The asphalt material may be heated in the' tank or in the hose connection or both, the object being to have it in sufliciently heated condition to be effectively sprayed and applied by the air gun. In practice the material leaving the gun may be around 300 F. for instance, and on contact with the wall or masonry may be at over 220 F.

This heating liquefies the asphalt and reduces its viscosity to such an extent that it is divided by the air blast of the air gun and projected in drops at high velocity so as to spatter and spread on the surface being treated and enter the crevices and pores of the surface so as to form a continuous, tightly clinging layer. Preferably the air gun nozzle is positioned within a few feet of the surface to force the material directly on to the surface and into the interstices thereof. The thickness of the layer may vary, and for instance at the rate of application of 15 to 20 square feet of wall surface per minute a coating to of an inch may be sufiicient for usual conditions, and a plurality of successive layers may be applied if desired.

The fluid asphalt in its heated condition also acts as a carrier and lubricant for the asbestos 01' other filler and permits the fibre to leave the nozzle of the spray gun without any clogging The spray gun is preferably of the type used for heavy liquids, such for instance as emulsions, and it is usual to supply the liquid to this type of gun under pressure. In cold weather and wherever desirable to overcome the cooling effect of the expanding air jet, I may heat the air supply to the gun sufficiently to avoid any over-chilling of the asphalt. This heating as well as the heating of the asphalt may be accomplished in any convenient manner, for instance by passing a current through the metal lining of a hose, this current being of sufficient amperage to give the desired heating effect and being controllable so as to control the temperature of the asphalt and the air as desired. In practice, I have found a pressure from 30 to 4.0 lbs. on the asphalt container is amply sufiicient, and a similar pressure for the air gun jet so that a single compressor can readily be used to supply both the asphalt container and the air gun.

While I have used the term waterproofing in the specification, I mean to have it understood in a very general sense of waterproofing, dampproofing or in any wise coating against moisture. The particular spray means is also immaterial providing that it gives the desired result of dividing the asphalt material in heated condition and projecting it against the surface. A centrifugal spraying means might be used as well as the air gun method above described in detail.

By the method of this invention the waterproofing material is applied by projection against the wall at any desired angle to the surface, preferably substantially normal to the surface; there is no substantial movement of the asphalt along the surface and each drop and particle of asphalt tends to cling in the position it strikes the surface. The hot asphalt also penetrates deeply into the masonry joints and brick masonry, and any porous material against which it is projected, giving not a mere film but an outer layer of any desired thickness securely anchored and bound to the supporting surface which is being waterproofed. This heating of the waterproofing medium also dispenses with thinning by any extra solvent, making the final layer in its originally admixture of over forty pounds of asbestos fiber to fifty gallons of the asphalt, heating said mixture and applying pressure thereto so that the hot asphalt acts as a carrier and lubricant for the fiber, and spraying said mixture at high velocity onto the surface to be waterproofed so that the asphalt and asbestos will form a continuous tightly clinging layer containing over 90% of waterproof material and the solvent will volatilize and cause the mixture to harden in place as a final completely waterproof coating of asphalt and asbestos.

WALTER H. STORM.