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<br /> <br />clear coatings depended on their ability to coat and penetrate the wall as <br />they were applied by spray or brush. Penetration of the coatings was uncer- <br />tain on a vertical wall, even when the wall was soaked and excess coatings <br />allowed to run down the wall. All of the cubes with the clear coatings leaked <br />when filled with water. The coated walls did not leak as much as an untreated <br />wall, but did leak excessively. The clear coatings were very effective at <br />beading and repelling rainwater, but they did not keep the cube from leaking <br />even against a small head of water. In general, the results of the clear <br />coating tests were unsatisfactory. <br />Cementitious coat inKs <br />Five cementitious coatings (coatings 4-8) were obtained for testing. <br />Four of these were proprietary products, and one was a formulation prepared <br />by the author at the US Army Engineer Waterways Experiment Station (WES). <br />There are many cementitious coatings which may make brick-veneer walls resis- <br />tant to water penetration; however, the above coatings were the ones initially <br />found for testing. Use of these coatings for testing does not constitute a <br />preference over other coatings not tested. The cementitious coatings devel- <br />oped a good bond with the brick-veneer wall. In general, the cementitious <br />materials made the walls relatively impermeable to a waterhead for heights <br />which are of interest in making homes resistant to floodwaters but some of <br />the coatings tested were not durable. Two coatings (5 and 8) have been suc- <br />cessful over an 8-year period of time subjected to the climate in Vicksburg, <br />Mississippi. <br />There were two procedures by which the various cementitious materials <br />could be applied to the surface of a brick-veneer wall. One of the five coat- <br />ings had to be troweled on the wall, while the others could be mixed to the <br />consistency of paint and brushed on the wall. Troweling on the coating was <br />time-consuming and thus increased the expense. It is highly desirable to use <br />a material which can be brushed on the wall. The troweled-on coating (coat- <br />ing 4) sealed the cube against a waterhead with only a small leak mainly at <br />the cube-foundation interface (Figure 45). Coating 4 was unsuccessful in <br />terms of durability. It expanded, cracked, and began to come off the wall <br />3 months after it was applied and had essentially come off the wall in 3 years <br />(Figure 46). <br />Three years after application of the brush-on coatings, coatings 6 and 7 <br />showed some cracking. Coating 7 lost its bond to the brick surface and peeled <br /> <br />52 <br />