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Show METHOD OF STOPPING LEA."., Concrete-Waterproofing Work Is Da scribed by Correspondent of the Engineering Record. The method of stopping leaks In concrete, described by a correspond' ent of the Engineering Record, con. sists in plastering the wet, leaking surface of the concrete with water proofed mortar. The mortar is kept from being washed away by suitable bracing against a properly constructed gasket. Assuming that a leak is to be repaired re-paired in a basement wall, Pig. 1, one foot or more above the floor, tha loose material should be scraped oi dug away, leaving a saucer-shaped cavity as large in, diameter as necessary. neces-sary. If the holes through which tha water Is leaking are large enough they can be stopped with plugs coy-wed coy-wed with patches of burlap driven In tightly. The form Is then prepared. In case the diameter of the saucer-shaped hole is six inches, a board, A, Fig. 2, two inches thick and eight lnchel square, will be required. A ona fourth-inch twisted-burlap rope, B, il tacked on the board and the lattel nailed to a brace C. Enough one-to-two mortar, water proofed, is prepared, to which haa been added, Just before leaving tha mixing box, bichromate of soda to the amount of one or two per cent, of tha cement. This Is added to make tha mortar quick setting. The mortar la placed on the board In a cone-shaped mass and then thrust quickly and firmly with a twisting motion Into the cavity. The brace Is driven Into place at the same time. The process is illustrated In Fig. 3. The twisting motion aids in forcing the mortar Into the smallest crevices and drives away such parts of the mortar as may have been squeezed out between the concrete con-crete and the gasket. A very simple application of tha method is shown In Fig. 4. A mora difficult application, but not impracticable, imprac-ticable, Is one where it is desired to fie. 4 F16.2 ,fi V J Concrete Work. plaster large areas. A little experience experi-ence and patience makes the mattei easy. A good waterproofing mixture la made as follows: Concentrated lya, one-third pound; powdered alum, three-fourths pound, which should ba mixed in one gallon of water at least one hour before using. All of this mixture is used to one sack of cement, and Is poured in at the same time aa the water used to temper the mortar. |