Article No: 79
Facing Down Hurricanes
By: Carole McMichael
Plantation Inc., a construction firm that builds along the North Carolina Coast, is very aware of the awesome and destructive power of hurricanes. According to David Spetrino, owner and vice president of Plantation, a large number of their clients have come to them specifically requesting ICF-built houses because they want to avoid the costly structural damage hurricanes and tropical storms can cause. One of their clients, who lived through Hurricane Andrew, wanted no more of stick-built houses.
Photo courtesy of Plantation, Inc.
Plantation is currently building a development on the coast called "Avenir." The site goes from relatively high ground with trees down to the end of a salt marsh. Chris Yerkes, an independent designer and special projects manager with Plantation, designed all of the houses in Avenir to be built from ICFs.
"We tried to design Avenir so the houses would have a European cottage feel," Yerkes said, "with steep pitched roofs, bump-out bays, and a number of dormers. All of the houses have a substantial front porch, 6 to 9 feet. Instead of just chopping the site into 16 parcels, we are grouping the houses in a village clustered around a green. Then we can leave larger areas of undeveloped land for communal use. We have a wetland park area and a community garden with grape arbors, and mature pecan and fig trees. Here people will have their own plots for planting vegetables or flowers.
"The houses offer a townhouse-type of ownership, including a small property buffer around the house and a private walled garden. If the owners want, they can pave the garden or put a pool in or an Asian water feature. The houses are designed so neighbors cannot look into other private gardens. On the neighbors' side, there are skylights instead of windows. All the front yards are maintained by the development association.
Yerkes, an engineer by training, built his first ICF house about 10 years ago. Because he lived on the hurricane coast, he was looking around for a product that was going to deliver the ultimate in exterior walls. Something that was going to be strong, energy-efficient, and at same time cost-effective and easy to build with. ICFs seemed to make the most sense. He came out of a background of industrial and commercial construction, so vertical concrete was not a radical departure or new technology that hadn't been tried in the market. According to Yerkes, using a form made out of the insulating material is really just an adaptation of what contractors have been doing all along.
"The first house was a combination of steel framing for the interior and roof and ICFs," Yerkes said. "A marriage of two technologies well-tested in commercial construction. I used the ReddiForm block for the first house and still use it. I chose it for a couple of reasons. One is that the block itself is builder-friendly — it has no top or bottom, so you can flip the block over, cut it in half, stack it and use the other portion. The corner interlock is very much like building with Legos. The wall ends up being very strong, even without the concrete in it. You have fairly few blocks — the corner, straight and pilaster. You can build an entire house, even with 45-degree angles in your walls, out of just two styles of blocks. As a result, you have less inventory and less chance of running out of something. Also, when the blocks are 1-foot-high instead of 16 inches, I don't have to cut them to build the classy 10-foot ceilings that are preferred in this area.
"The other reason I like ReddiForm is the pour. With a lot of ICFs, you pour in 3- or 4-foot lifts. With this system, you can pour a full 10- or 12-foot lift. You start in the corner, fill the corner up and just march all the way around the house once and you're done. I have never had a blowout, not even close to one. In fact, in the last house, we forgot to brace a corner. I walked around the house and thought 'Oh my gosh.' But even with the 11-foot lift, it wasn't a problem. I'm also pleased that the bracing on that form is determined more by where you need bracing for walk boards rather than for the wall itself. The wall needs it only once every 10 feet.
A rare bird
As with many ICF builders, Yerkes noted that getting an ICF-experienced crew is a problem. But rather than require a crew that has built with ICFs over and over, he relies on having just one person who knows what he is doing, then picking up two or three helpers. In fact, the crew on the first Avenir house was completely inexperienced. The crew did not speak English; the foreman had limited English; and although they were an experienced concrete crew, they had had no ICF training.
"It was easy to show them what we wanted," Yerkes said." I was onsite and checked everything. They picked up this process pretty easily, and got the house done on time. The ICF portion of the house went very smoothly and probably was the least complicated thing we did.
"Finding experienced subcontractors was not a problem either because, in addition to being a licensed general contractor, I am a licensed electrical, plumbing and mechanical contractor. I have the experience to explain how ICFs change things, show the subcontractors how to do it, and where to find it in the code."
The Avenir house
The first house in the Avenir development is a story-and-a-half house with 3,000 square feet: 2,000 square feet downstairs and 1,000 square feet upstairs. The upper floor is built within the structure of the roof. These houses are meant to appeal to empty nesters. Downstairs there is the master suite, laundry, kitchen, dining room, family room, living room and study. It is where the couple would live 99 percent of the time. Upstairs, there are three bedrooms and two baths, serving as a kind of overflow space for when the children visit.
"I designed a series of houses that follow a similar theme," Yerkes said. "People can mix and match from six different elevations and four different floor plans. The advantage of having the main rooms on the first floor is that they all look out or open out to the 1,000 square feet of private garden. It is L-shaped with set backs and functions as an outdoor room. If the house is raised, the garden is raised as well, so it is always just a step down. I'm a big fan of universal design restraints. If you have only one step above grade, people with mobility problems can handle it."
In this part of the country, the water table may only be 18 inches to a couple of feet below the surface, so builders tend to build with a raised slab. For the Avenir house, Yerkes did a floating slab that insulates the edge of the slab. As a result, the floor is less prone to structural cracks and the house produces better thermal performance. The porches are finished in decorative, acid-etched concrete. Hardwood floors, the market's preference, are laid over the slab.
"We hired a company to do a complete energy profile," Yerkes said. "For its size, the house is very energy efficient. It uses a single 3.5-ton variable speed air-conditioning unit. We also are using radiant barrier sheathing for the roof, with 30-pound felt and 40-year shingles, which stand up pretty well to hurricanes. This first house served as a test for seeing how energy-efficient and comfortable the house would be if we eliminated roof vents. In hurricane country, it can rain horizontally and drive moisture in through the vents."
The Avenir house meets the new International Building Code, a requirement for maintaining healthy indoor air quality. Yerkes prefers to bring in outside air in a controlled fashion, filtering it for pollen and heating or cooling it before it is introduced into the house. He also installed transfer grills on doors for air circulation, rather than the conventional practice of undercuting the doors.
The house has a manifold plumbing system similar in concept to an electrical breaker panel. It allows the owner to turn off the water to any individual fixture in the house. For example, he can turn off the hot water on the left-hand sink in the upstairs bathroom or the cold water to the shower in the downstairs bathroom. All the houses in Avenir will be prewired for CAT 5 E wiring. Owners are offered a standard package and the option of upgrades to whole video, audio or house automation. The security wiring is there as well."
According to Yerkes, the more educated the consumers, the more they want to live in an ICF-built home, particularly after they have been through a hurricane. One client, who was in an ICF house when a hurricane passed right over the area, thought the hurricane, which came through at night, had missed them. He hadn't heard or felt anything.
The marketer's dream
"I haven't done much to find clients," Spetrino said. "People see ICF Web sites, read magazines, talk to local contractors or distributors or go to trade shows. They go to an ICF chat room to talk with others who are building with ICFs, checking pros and cons.
"In general, they are much more knowledgeable than they were five years ago; so much so, that many have decided on ICFs when they come to us. I don't have to do a lot of selling. It sells itself."