US2283573A - Method of waterproofing and preventing efflorescence of mortar in masonry - Google Patents

Description

106. COMPOSWONS,

COATING OR PLASTlC Patented May 19, 1942 VENTING E IN MASONRY ramb NITED STATES PATENT OFFICE METHOD OF ATERPROOFIN AND PRE- I MORTAR James B. Pierce, Jr., Charleston, W. Va., assignor to Standard Ultramarine Company, Huntington, W. Va., a corporation of West Virginia No Drawing. Application December 24, 1938, Serial No. 247,645

5 Claims.

of either calcium, aluminum and ammomum "have been' mployed' 'foFth'Fpurpose of rndsrmg masonry walls waterproof. While these products are highly water-repellent and therefore adapted for retarding the penetration of moisture through a masonry wall, whether the same be due to faulty coping, bad flashing or otherwise, nevertheless, they are wholly ineffective for preventing the efllorescence of the mortar employed in laying up brick, tile and other masonry walls since they are incapable of fixing sulphates of alkali and alkaline earth metals, which salts are the prime cause of such eillorescence. Moreover the waterproofing ac- ,situ in the mortar of such brick, tile Or like masonry walls while the moisture will collect on the surface of the wall as an innocuous film which evaporates without leaving a trace of efflorescence.

As an example of the preferred manner of waterproofing and preventing eiilorescence of mortar in brick, tile and other masonry walls laid up with mortar, the following is submitted: Equi-molecular proportions of solid stearic acid is added, with constant stirring, to concentrated barium ul hide 1i r of from 10% to 20% BaS content whereupon the same react to form insoluble barium stearate in the form of a flocculent reci ta s and gi ls eai lnhi sm with standar tion of stearates of calcium, aluminum and ammonium, however, is not by any means perfect and even when considerable quantities of these stearates are added to the mortar, for example up to 3%, some moisture will pass through the mortar, after the same is set, especially after severe weather conditions and when this occurs elllorescence in the wall is bound to appear.

My investigations have led to the discovery that barium s ossess all the desirable waterproofing qualities of the aforesaid stearates and in addition thereto, reacts with the sulphates of alkali and alkaline earth metals to form msoluble barium suI Kate and the corresponding alkali or a a ine ear arate thereby functioning as an e ective eillorescence reventativg,

besides serving as swam rproo g compound, when incorporated with e mor ar 0 suc wa prior to the laying up of the wall. Furthermore, although the barium stearate may not be, under the most severe conditions, an absolute waterproofing agent for masonry, nevertheless whatever moisture passes through a wall, which has been subjected to the hereinafter described treatment with barium stearate, "will not act as a carrier or vehicle for soluble efllorescence-producing sulphates, such as aforesaid, due to the fact that such sulphates react with the waterproofing and efiiorescence-prevention agent and, as a consequence, insoluble barium sulphate and the corresponding alkali and alkaline earth stearates will be formed The precipitate is thoroughly washed with water to free the same from occluded HzS, then filtered, dried and powdered in accordance processinEfi'tlTtTd's'T' In the treatment of mortar intended for use in the laying up of masonry walls of the aforesaid types, an amount of barium steargg produced as aforesaid, equal to to 3%by weight of the amount of mortar, whether lime mortar or Portland or other cement mortar be employed in laying up the wall, 18 mtimately' admixed with the mortar, while the latter is in the usual sloppy state and such mortar while still fresh is then employed to lay up the desired brick, tile or like masonry wall. But about of barium stearate is usually efiective in preventing subsequent efllorescence in the wall so laid up with the mortar treated as aforesaid but an amount of 3% of such stearate will insure absolute protection against any such efilorescence even under the most severe conditions. However, except in those cases where the coping and/or flashing is poor and very severe weather conditions are experienced accompanied by alternate freezing and thawing over several months at a time, the smaller amount of barium stearate, namely but about /z%, usually suflices to afford very satisfactory protection. In addition to serving as an effective efllorescence preventative in an outside wall, such barium stearate can also be advantageously employed as an ingredient in the mortar of the back-up tile or other similar lining material of a wall, since whatever moisture may enter the masonry wall will pass into the mortar of the back-up tile and, when the wall again dries, since the outer wall dries first, it will pull the moisture outwardly into itself whence it passes outwardly and evaporates, thus effectively protecting the back-up tile against being disin colored or disfigured by ugly effiorescence stains.

The wet or sloppy mortar mix herein referred rom slaked lime,

to is that commonly prepared f either water or air-slaked lime or from Portland or like cement in admixture with the requisite amount of water and sand crushed marble or other inert granular martin common y'employed to form a mortar of the usual consistency and lime or cement content. As is well known in the case of ordinary lime mortar, the calcium hydrate is essentially converted on aging to calcium carbonate.

ficial tile, sincesuch barium stearate'is' equally effective in preventing efliorescence in such blocks or slabs, as well as mortar, provided it is not heated to a temperature in excess of its decom position point.

While I have specified certain preferred proportions of ingredients in the production of the barium stearate and in carrying out the aforesaid treatment for proventing efllorescence in masonry walls, various changes in such proportions and in the exact method of procedure, herein outlined, may be made without departing from the spirit of my invention as embraced within the scope of the appended claims.

Having thus described my invention, what I claim and desire to obtain by United States Letters Patent is:

1. The method of making a highly waterrepellent and substantially non-efllorescent mortar for masonry, comprising incorporating with a mortar, belonging to the group consisting of lime mortar and Portland cement mortar and containing an appreciable amount of a water-soluble, efllorescence-forming compound belonging to the group consisting of an alkali metal sulphate and an alkaline earth metal sulphate, an amount of barium stearate which is at least substantially the chemical equivalent of any such watersoluble compound and efiecting thereby the precipitation in situ in such mortar of barium sulphate and calcium stearate.

2. The methodof making a highly waterrepellent and substantially non-efllorescent mortar for masonary, comprising incorporating with a mortar, belonging to the group consisting of lime mortar and Portland cement mortar and containing an appreciable amount of a.watersoluble, efllorescence-forming compound belonging to the group consisting of an alkali metal sulphate and an alkaline earth metal sulphate, an amount of barium stearate which is from 4% to 5% of the weight of the solid content of the mortar and which is at least substantially the chemical equivalent of any such watersoluble compound and efiecting thereby the precipitation in situ in such mortar of barium sulphate and calcium stearate.

3. A waterproof and substantially non-efllorescent mortar belonging to the group consisting of lime mortar and Portland cement mortar and containing barium sulphate and calcium stearate each precipitated in situ therein, the amount of the stearate radical in such precipitated calcium stearate being the chemical equivalent of an amount of barium stearate equal to from to 5% by weight of the solid content of the mortar but not substantially exceeding the chemical equivalent of the barium radical in such precipitated barium sulphate and substantially the sole waterproofing agent present in said mortar comprising a stearate of an alkaline earth metal.

4. A waterproof and substantially non-efllorescent mortar belonging to the group consisting of lime mortar and Portland cement mortar and containing barium sulphate and calcium stearate each precipitated in situ therein, the amount of the stearate radical in such precipitated calcium stearate being the chemical equivalent of an amount of barium stearate equal to from to 3% by weight of the solid content of the mortar but not substantially exceeding the chemical equivalent of the barium radical in such precipitated'barium sulphate and substantially the sole waterproofing agent present in said mortar comprising a stearate of an alkaline earth metal.

5. A waterproof and substantially non-efllorescent mortar belonging to the group consisting of lime mortar and Portland cement mortar and containing barium sulphate and calcium stearate each precipitated in situ therein, the amount of the stearate radical in such precipitated calcium stearate being the chemical equivalent of an amount of barium stearate equal to about by weight of the solid content of the mortar but not substantially exceeding the chemical equivalent of the barium radical in such precipitated barium sulphate and substantially the sole waterproofing agent present in said mortar comprising a stearate of an alkaline earth metal.

JAMES B. PIERCE, JR.