CoatingsPro Magazine

MAY 2016

CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.

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Page 67 of 84

COATINGSPRO MAY 2016 67 Figure 2. Excessive water leak coming through bulkhead above window The only section of wall that had been recoated had excessive blistering to most of the mortar joints. When the blisters were popped, they were full of water. Te elastomeric wall coating was applied and, to the dismay of everyone, the water leaks were not corrected. Tis was the second time the exterior walls had been coated. Everyone was at a loss. W here was the water coming from? After several meetings, it was agreed that the condominium property manager would have the coating work inspected by an independent third-party coatings inspector (me). Tese fndings were quite difer- ent from those of the contractor and material supplier, which had showed that there was sufcient dry flm thick- ness (DFT) and that the wall coating system had been applied properly. Instead of what the contractor and material rep found, I found that the water leaks were a direct result of an improperly applied elastomeric wall coating system. If You See Something… Te inspections began with a visual assessment of the entire building exterior. Te visual assessment revealed excessive pinholing to all areas of the building. It appeared that many large areas had been sprayed and not backrolled. In fact, it appeared that very little backrolling had been done at all. Te coating was so thin in some areas that you could see through it. In one location, water was observed to be running out of the CMU. Te only section of wall that had been recoated had excessive blistering to most of the mortar joints. W hen the blisters were popped, they were full of water. Te coating in these areas was easily removed by fngernails. A scissor lift was used to inspect the top portion of this wall. Tere were multiple mortar joints where the coating had completely delaminated. Some of the delamina- tions were 10 feet (3.1 m) in length. Te CMU at the top of the wall just under the fashing had little to no coating applied to it. Tere were masonry joints on the top of the wall with numerous holes and gaps. One joint had no mortar in it at all. An ultrasonic thickness gage was used to measure the DFTs of the applied coating. Te readings were 3.0 to 6.0 mils (76.2–152.4 microns). Te elasto- meric wall coating was scraped of in several locations to reveal the exist- ing coating. Te DFTs of the existing coating were between 2.0 and 3.0 mils (50.8–76.2 microns). Tis meant that the elastomeric coating was only 1.0- to 3.0-mils (25.4–76.2 microns) thick, which is well below the minimum of the average thickness of 8.0 mils (203.2 microns) required by the manufacturer. I was also able to easily remove the coating from the split face CMU with my fngernails where multiple coats had been applied. W here the coating was removed or blisters were broken, there was moisture. Te CMU was completely saturated. A spring micrometer was used to measure the thickness of the coating removed from these areas. Te DFTs were between 15.0 and 16.0 mils (381.0–406.4 microns). Tis exceeded the maximum average of the 12.0-mils (304.8 microns) thick stated on the manufacturer's product data sheet. Te contractor's documentation revealed a serious faw in his appli- cation procedure. Te exterior of the building had been power washed, which had undoubtedly put moisture into the CMU. Te coating should not have been applied to a damp surface and, once the coating was applied, it trapped the moisture inside the wall. Applying multiple coats to the lower portion of the wall without sealing the top made the problem even worse because the wall was flling up with moisture. To make matters worse, this was a south-facing wall, which meant that while the hot sun was trying to draw the moisture out of the wall, the thick flm of the coating prevented the moisture from passing through Elastomeric Wall Coating

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