Concrete Coatings Articles

“Lotus Power” Solves Condo’s Water Intrusion Problems

Photos courtesy of Prime South
Vendor Team

Edgewater Condominiums
Coatings client
Myrtle Beach, SC
(843) 390-1742

Premier Exteriors
Coatings contractor
Ridgeland, SC
(843) 645-6920

Prime South
General contractor
Wake Forest, NC
(919) 872-6711

Pyramid Scaffold Services
Equipment manufacturer
Princeton, NC
(919) 879-8930

Sto Corp.
Materials manufacturer
Atlanta, GA
(800) 221-2397

The coastal city of Myrtle Beach, S.C., is home to more than 33,000 people, of which a fortunate few reside at Edgewater Condominiums. A gated community located along the Intracoastal Waterway, Edgewater holds 260 units in its 10-building complex. While these buildings were completed about a decade ago, the Edgewater board of directors recently voted to replace the stucco in them due to significant water intrusion issues.

Jason Smith, AIA, senior architect with Construction Science and Engineering, assessed the situation and determined that the solution was a Level 4 Remove and Reclad — an extensive renovation program created by building materials manufacturer Sto Corp. in which all existing cladding is replaced with a sustainable wall cladding system. In terms of what system should be specified for the 10-building condo project, Smith went with approximately 250,000 square feet (23,225.8 m2) of StoTherm ci Lotusan, a continuous exterior insulation and finish system (EIFS) that provides air and weather tightness, long-lasting thermal performance, and durability.

The Power of Teamwork

In tandem with the Edgewater board of directors, particularly board director Chris Rush, Smith assembled a formidable team of contractors for the project. At the head of this team was Prime South, a local general contractor that had used Sto products since 1990 and completes an average of 30–50 EIFS projects, annually.

According to company owner Al Best, the bottom floors of the buildings were concrete, while the upper floors had oriented-stand board (OSB) sheathing, of which about 15 percent had deteriorated to the point of uselessness and needed to be refinished. He summed up Edgewater’s water intrusion issues thusly: “The exterior building envelope was failing on a systematic level. It had deteriorated to the point where [Edgewater board members] were having numerous homeowner complaints, and it was not practical, or efficient from a cost standpoint, to try to address all of the individual issues.”

To be sure, tackling a project of this size and scope — and with Edgewater residents on the premises, no less — would be a massive undertaking. Best estimated that there were 50 crew members at work during the 30-month-long project, of which about a dozen were involved with the applicators from Premier Exteriors. The coatings crew generally worked 10-hour shifts from Mondays to Thursdays, along with some occasional Fridays and Saturdays when weather delays forced them to make up for lost time.

In addition, this Level 4 project posed a number of unique architectural challenges, ranging from low-slope roof membranes and clay tile roofs to existing windows that had to be left in their openings, in accordance with local guidelines. “The building had a fairly intricate design,” Best said. “You have all these penetrations and details and dissimilar materials that all have to be joined and detailed. From a water intrusion standpoint, that’s very difficult to do.”

Initially, the project had been specified with a new hard coat stucco, but Best believed it would have resulted in a messy application process and have caused further delays. By contrast, the StoTherm ci Lotusan system was everything the crew could’ve hoped for. “The materials are lighter and not nearly as messy as conventional stucco, so we were able to control the [worksite] environment,” Best said. “It was a lot easier to keep the area clean and safe, and let the homeowners continue to come and go.”

Sticking to the System

The component parts of StoTherm ci Lotusan system include StoGuard, a fully adhered waterproof air and moisture barrier; StoTherm, an insulated cladding and drainage wall system; and StoLit Lotusan, a textured finish with self-cleaning properties that mimics the self-cleaning capabilities of the lotus leaf. Other manufacturer products used during the project were StoGuard Fabric, Sto TurboStick, Sto Primer-Adhesive B, and StoMesh.

First, the crew used a multi-step sequencing system that tilted windows in and out to flash their openings without removing them completely (and thus violating the aforementioned local guidelines). These windows were cut from the interior side of each condo unit, flashing installed, and openings wrapped with StoGuard Fabric. A similar procedure was also performed for wall and perimeter flashings.

Next came the StoGuard waterproof air barrier — or to refer to it by its brand name, the Sto Gold Coat. This product was roller applied in two coats until it was opaque to achieve 12–16 mils (304.8–406.4 microns) wet film thickness. Due to Edgewater’s sprawling size, crew members could work on flashings while their comrades came behind them to roll on the Gold Coat layers. “There were areas where the Gold Coat actually had to lap behind the steel flashings, so when they were put on, the last couple of inches had pieces of self-adhered paper left on,” Best said. “That allowed the Gold Coat people to lift it up, put the Gold Coat on, peel that paper off, and lap it down over the top of the flashing that then directed water out of the window.”

As the Gold Coat dried, StoTherm exterior wall claddings were applied in vertical ribbons to expanded polystyrene (EPS) boards using Sto TurboSticks, a ready-to-use, single component polyurethane foam adhesive that is dispensed through connected application pistols and hoses. These EPS boards — which Best estimated were about 0.5-inch (1.3 cm) foam and 0.5-inch trim — were adhered to the exterior walls. Additional insulation was applied in gaps and breaches not covered by the EPS boards.

A basecoat of Sto Primer/Adhesive-B was applied to the wall to an average of 1/16th of an inch (1.6 mm) with fiberglass Sto Mesh embedded into it. The coating was installed smooth to the point where the mesh pattern was invisible to the naked eye. To finish things off, a coat of StoLit Lotusan was applied to an average of 1/8th of an inch (3.2 mm), which had aggregate in it in order to control coating thickness. “The Lotusan has a chemical in it that allows natural rainwater and takes pollution, dirt, and dust with it as it rolls down the wall, which is the self-cleaning element to the finish coat,” Best explained. “This allows it to look new and clean longer.”

Safety has long been a Best practice for his jobsites, particularly when it comes to scaffolding. “It has always been my belief that the better the scaffolding set-up is, the more efficient, safer, and better the project is,” he said. To that end, the crew erected scaffolding, used system frames, built stairs, and had safety rails and netting — all courtesy of Pyramid Scaffolding Services. In addition, they wore safety harnesses, and there was 100 percent tie-off throughout the project.

Calm Before the Storm

Arguably the biggest challenge the crew faced was dealing with the unpredictability of Mother Nature. During the 30-month project, the Myrtle Beach area was hit by three named hurricanes: Florence, Michael, and Dorian. According to Best, two of the three hurricanes were predicted to be severe enough that the crew saw fit to remove walk boards and tie down equipment. And with high winds up to 75 miles per hour (120.7 km/hour), there was reason for concern. But aside from some damaged EPS boards, Best said the project emerged relatively unscathed. “I would say we were fortunate that they were all glancing blows.”

Best was there to experience these hurricanes firsthand, as he chose to live on-site for much of the project. What motivated that decision? “The idea about being there on-site, and sharing my cell number with the owners and letting them know where I was, was that if they had some issue, they would come directly to me with it, and it would be dealt with immediately,” he said. “The board thought I was crazy to give out my number, that I would be harassed and wouldn’t have a moment’s rest. That probably took place for the first month or two, but after that, it kinda set the tone and the residents, for the most part, were very cordial. They realized their issues were going to be dealt with, and I think it made them calm and reassured.”

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