Article No: 144
WANTED: ICF building specialists
By: Carole McMichael
When homeowners look for a builder for their ICF home, one of the biggest mistakes they can make is selecting someone not specialized in building with ICFs. "It looks so easy, they think everybody can do it," says Ivan Richardson, president of R & T Construction in Urbana, Ill. "However, you have to get it right the first time."
The lack of expertise that some customers encounter can, unfortunately, hurt the concept of concrete houses. First-time builders generally attend seminars with their crews to get some training, but sometimes that is not enough. When they build that first house, installation time and cost may be more than expected; they may not receive enough input from distributors, or not know enough about the process to ask the right questions. Homeowners can end up with a less-than-positive experience - and bad news travels fast.
"There are not that many people in this area who are experienced in ICFs," Richardson says. "People want me to hire guys and take on more jobs, but there is no way I would do that unless I can oversee everything I sell. The subs specialize, so it makes sense that we need more people who specialize in doing the block."
Richardson points out a few of the things that can cause problems for first-time ICF builders. Not all block distributors are equal when providing onsite assistance and follow-through. The foam on the forms, which are not always stored inside, can get brittle and crack. Blocks might shrink slightly if they sit in sunlight too long. When using several such blocks in a row, that shrinkage can produce greater-than-expected tolerances. There also can be some problems with snapping blocks together, if new loads of block are mixed with old.
"What's good about being specialized in block is you have the experience to make it work," Richardson says. "You can teach a crew everything in the world in the classroom, but when they get out on the jobsite, they may forget. I have builders get with us on the jobsite for hands-on work with our crews to explain things. You see things happen, and you find out why and show them what to do. The more you work with block, the better you get at it, especially when you have the same people doing it over and over. It only takes three people, which isn't a big crew."
Changing to concrete
"I first got introduced to insulated concrete blocks when I did a basement for my own home," Richardson says. "Because I've always been in construction, I understood the concept, and I liked the idea of the insulation and concrete.
"Now, I am an Arxx Block distributor. The Arxx Block has so many great features. For example, the post form provides all the same distance for the electrical installation. It has nubs so the forms can't slide. The Styrofoam is 2 1/2 inches on each side and doesn't vary as it goes down the wall. They have new ties you can pour right in the wall to set the floor joists without putting in a brick ledge. They really improve their block every year.
"In the Urbana area, we have been building for about 12 years in a 140-acre subdivision. The first phase was stick-built. We started building with concrete about five or six years ago because of its energy efficiency, tornado protection and sound reduction. Currently, we have 12 condos of about 4,000 square feet apiece and 20 completely concrete homes. In the apartments, I provide a concrete envelope using precast floors and ceilings. This makes it ideal to include a safe room, which can double as a wine cellar or a vault room, but people tend to see the whole structure as a safe room. [In the houses,] most floors are finished as they would be in regular construction, but I personally use concrete floors for sound and fire protection."
There are four lakes in the subdivision, and many of the two-story houses have walkout basements and decks or cantilevered balconies to take advantage of the view. Richardson hired an architect to design a variety of floor plans. This allowed him to run cost comparisons on the different styles, seeing which gave the customer the most house for the money. He also did a comparison of geothermal and total electric heating systems, and found the latter to be more cost-effective. All the houses were done on spec to be used as models.
The pre-erection stage of planning involved Richardson and the architect. He chose not to include the various subcontractors at this stage partly because, with his building experience, he already knew what they would need and could ensure they would have it, and partly because most of the sub work is not in the block.
"[Before erection begins] you do have to line up all the crews and subs, so they don't get in each other's way," Richardson says. "There is no problem if you are a major contractor. It will take longer for a smaller builder, but it is no harder for the ICF small builder than for the wood-frame small builder.
"I didn't find any contractors with ICF experience, so I trained them. Most of them like working with the ICFs as much or better than with stick. The HVAC guy was overwhelmed with how small the furnaces and air conditioners needed to be: If the owner lost power in winter, it would be a week before it got cold inside."
"Footings vary according to engineering," Richardson says. "Instead of rebar protruding up from the footing, we do a keyway that keeps the block from moving, and glue the first course with urethane guns. The plumbing in the basement is done before the slab is poured. We do the basement and do one course of block above the subfloor level. As we stack the rest of the block up to the ceiling, the rebar, which snaps into a channel in the form, is put in every 3 to 4 feet - that varies. There is more rebar above the windows and doors to provide for the extra load.
"The framers come in to snap lines before the subfloor is set. Interior walls have to go up for the next floor. After the first floor is stacked and braced, we do the pour; the framers put in the floor joists that the main floor sits on. We go on to the next story to stack the block for the walls. To attach the regular wooden roof trusses, J-bolts are embedded in the concrete. The roof can be insulated just as in regular construction. The finished ICF wall is 11 1/2 inches, with 6 1/4 inches of it concrete. We pour one floor at a time and can build up to seven stories."
When Richardson's crew pours a straight wall, they use a regular mix; however, if the house plan involves many windows, they sometimes add a pea gravel, as it makes the concrete flow more smoothly around openings. They also use a pencil vibrator to ensure there are no air pockets or voids formed. Total erection time, if everything is lined up, is approximately 10 days.
"The code inspectors really wanted to see the houses, not just have the facts," Richardson says. "Once they got familiar with ICF construction, the fire department found it so much safer than wood-frame. You've got solid concrete, which is a natural fire wall - that makes ICFs tremendous in apartments. Most insurers will give you a break, too. About five years ago, we had a tornado right here in town. The owners of an ICF house had only been in it a week or two when the tornado struck. All the houses in the area were completely destroyed, taken right down to the subfloor, and this two-story stood 100 percent."
The perfect marriage
Richardson finishes most exterior walls with the Dryvit Textured Acrylic Finish system, also known as TAFS. "You can use anything, but Dryvit is ideal for concrete," he says. "There isn't going to be any moisture coming through the walls as you might have with stucco on wood. It won't tear and is easily repaired, unlike the original stucco. You can pick out any color you want, mixing the color in the Dryvit or putting on a stain. It is becoming popular for finishing out basements, as well."
Cold weather can affect Dryvit application, just as with brick, so the crew needs to work under a heated tarp or plastic tent. Once the windows are set, the crew is ready for the Dryvit process, which takes about 24 hours to cure. Because Dryvit can be used to create a variety of different textured finishes, a contractor doesn't have to hire a number of different trades to offer his customers a range of styles.
People love the ICF concept, but model homes - where potential homeowners can breathe that healthy air and feel the incredible quiet - are perhaps the best marketing tool out there. That is easier said than done for Richardson, because his subdivision spec homes sold before he really got to use them as models. He has found that the key to marketing is having the proof in hand: the energy bills of the people who are living in his houses in bone-chilling Illinois winters. For example, one owner paid just over $600 a year in energy costs, in a 4,000-square-foot house. According to Richardson, this is the most effective kind of marketing in a world where the energy situation is not going to get any better. It is working for him? "I keep so busy, I'm not hunting new business," he says.
For more information on Arxx Block, visit arxx.com. For more information on Dryvit Systems, visit dryvit.com.