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Installing Electrical Systems

Finding subcontractors familiar with ICF construction can be challenging, especially for electrical and plumbing work.            

Matt McCoy, president of South River Construction, deals with the issue regularly. Just last month, he traveled to Dallas to teach a hands-on training course to area electricians. “Finding and retaining quality subs is one of the most pressing issues I have to deal with,” he says.

If you’re having difficulty finding a sub, McCoy recommends looking for someone that’s willing to try something new. “I try to find guys that still have a passion for construction, someone that’s excited about doing good electrical work, that’s willing to go beyond just doing things the way they always do it. If they’re just interested in making a buck and moving on, they’re not going to be interested,” he said.

  Pat Moore, of Brocon, Inc, says finding subs for ICF work is “a little more difficult but not extremely. People who haven’t done it are apprehensive, but once they’ve done it, they see it’s not a big deal at all.”

Both Moore and McCoy work on jobs across the United States, and say that the idea that it costs more to wire an ICF house is simply untrue. “On their first job, they’ll charge a premium,” admits Moore, “but once they get caught up it’s about the same.”

Mike Dye is a licensed electrician who has done the wiring on several ICF homes, including his own. “It’s a lot less complicated that most people think,” he says. “You don’t have that much of the work tied up in the outside walls of the house, and the inside walls are going to be the same. All you’re doing is snubbing into the nearest interior wall. Except for a porch light or maybe a couple outlets, it’s really the same as any other job.”


Another item that builders deal with is whether to run the wires in conduit or to set them directly in the foam.

For commercial contractors, code requires conduit. But Dye recommends it for residential jobs too. “Conduit is protected. You don’t have to worry about running a screw into it.” He adds that any electrician with commercial or industrial experience is going to be familiar with it, which may make getting bids easier, and is just as easy.

“If it is more difficult, it’s not much,” Dye says. “I get a box the same thickness of the foam, and I mount the boxes first.” Then it’s a simple matter of drawing the conduit routes on the walls, installing it, and pulling wire.

Brad Hebig, president of Plastilock Corp., lists another reason for using conduit: it makes upgrades possible. Since ICF homes will probably last 400 years or more, that’s something to consider. But even on shorter time scales, it comes in handy.

“Phone lines, computers, cable, that stuff is changing constantly,” says Hebig. “Let’s say you need to split a circuit, or you install a home office and need another couple phone lines. It is much, much easier to do that if you use conduit.”

The Plastilock system runs through the core of the ICF block, with conduit placed prior to the concrete being poured. That means builders can use the cheaper PVC or flexible SMRF pipe in place of metal. It eliminates the need to cut channels in the foam, and overall “just gives a cleaner look” to the jobsite,” says Hebig. “You wouldn’t sell a car to someone, and then smash out the windows,” he says. “Well, that’s what you’re doing when you sell an ICF house and then shred the foam to pieces.”


The problem with putting the conduit in the concrete, says Dye, is that most people don’t plan that far ahead.

 McCoy prefers conduit—“It’s more flexible when you make changes”—but says it’s easier to come back and place it in the foam afterwards. “It’s less coordination for the general contractor and less hassle for the electrician because he doesn’t have to work around us while we’re stacking block.”

“If you can minimize the amount of stuff in the way of the wall stackers, you’ll be that much ahead,” he says. He claims electricians like it better that way too, when the walls are “clean, flat and ready for them, with no bracing, rebar, scaffolding and other things in the way.”

 He says doubling up the plumbers and electricians works well. “Let’s say you’ve got the plumber starting, and the electrician behind that, followed by the low voltage guy doing your phone, they’re going to be out there at the same time anyway to do the HVAC.”

McCoy adds that it’s more expensive to place conduit in the walls prior to the pour. “It’s similar to masonry, where you’re paying two electricians full time doing nothing but watching the walls go up, occasionally adding four-foot sticks of conduit.” Hebig argues that the stackers can place the conduit, but admits that inspectors and code officials sometimes frown on the practice.

Pat Moore sums up the issue. “It really comes down to the preference of the contractor and the timeline of the job. If you do run inside the ICF wall, it really bases off the timeline, and if you’re running on a tight schedule, it’s easier for the electrician to come back in and cut out the foam.”

Cutting Foam

Methods for cutting wiring chases seem to be as varied as the contractors themselves.

“An electric chainsaw is really, really fast,” says McCoy. “Electric barbeque lighters that get hot work well too. They melt the foam faster than anything I’ve every seen.”

Dye uses a cordless Sawzall. He says it produces less mess than a router or chainsaw, and cuts ties—plastic or metal—without problems.

Dean Seibert, president of Wind-Lock, cautions against using routers, chainsaws, and similar tools. “Accidental gouges in the foam can allow concrete to creep to the edges of the block. If you hit that with a router, the concrete is going to come flying out of there like a missile, and someone is going to get hurt.”

He says chainsaws are slightly better than the router, but safety is still a factor. “You’re going to have a guy standing on a bucket, using a tool that’s meant to cut tree limbs.”

And then there are the other disadvantages, like making your jobsite look like it’s been hit by an EPS blizzard. And if there’s a breeze, watch out. “Routers and battery chainsaws produce a dust that seems to be attracted to the neighbor’s black BMW,” says Seibert.

Use a hotknife, says Moore. “It’s lot cleaner. The older ones were a little time-consuming, but the new SuperGroover from Wind-Lock is really fast. We just bought a couple of them and have been really impressed.”

Unlike ordinary hotknives, which were developed for the light-duty foam used in the EIFS industry, the SuperGroover is designed specifically for ICFs. It uses transformer technology and is driven by a heavy-duty belt pack.

Seibert warns that while the SuperGroover will cut through plastic ties, it’s not recommended as it will melt a significant portion of the surrounding EPS.

It’s better to lay out the wiring to avoid ties entirely. Most blocks have at least one section where the ties are deep enough to cut horizontal chases without hitting the ties. Vertical runs, of course, present no problems.

Dye adds, “Once you get into it you’ll see that it’s not that big of an issue. After you do one job and see how easy it is, you won’t have any problems with it.”

Moore says that with the increasing popularity of ICF construction, it’s only a matter of time until most electricians are familiar with the material. “It’s a learning curve utility contractors have to adjust to, but they’ll have to adjust sooner or later.”

Exclusive web content:
See how fast the SuperGroover cuts through foam.

Lean how to install electricity under the sheetrock.

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