If you follow the right steps, use the best tools, and build with a wiring-friendly ICF system (spoiler alert – it’s Element ICF!), cutting chases and electrical box pockets can be a breeze.
In the guide below, we’ve put together some handy info to make the job easier for you. We’ll walk you through the basic steps for cutting wire chase channels and electrical box pockets, explain which tools work best, and explain the advantages of Element ICF walls for wiring.
We’ll also give you three straightforward tips that really simplify the task of cutting through ICF foams and embedding the wiring.
How to Install Wiring in ICF Walls
There are two ways to install wiring in ICF walls:
- In-conduit wiring, which is placed within the concrete core before the pour. However, In-conduit wiring limits repair access to the concrete-enclosed wires and requires having to make a series of wiring-related decisions quite early in the construction process.
- embedding the wiring into chases that are cut into the ICF foam panel after the concrete is poured. This is the most common way of installing wiring into ICF walls and we will explore this method further below:
Below are the two simple steps you can follow to prepare the foam panels for the wires and wall boxes.
1. Cut the wire chases
The first step is to cut horizontal channels for the wire chases. There are two things for you to keep in mind as you make your cuts:
- Maintain appropriate depth: For your work to be code-compliant, the wiring should generally be at least 2 inches deep in the foam. That said, this requirement may vary between jurisdictions, so it’s always best to confirm the minimum depth with local building officials.
- Beware of cutting through plastic webs: As you’re cutting the wire chases, there’s a chance you’ll have to cut through continuous plastic webs, which is harder and messier than it looks.
However, Element ICF webs by design leave a 1.5-inch-wide space in the foam where the blocks connect, creating a 1.5” wide horizontal all-foam channel every 16” o/c – which is a natural location to create your wire chases without the inconvenience and difficultly of encountering hard plastic webs.
2. Cut the wall box inserts
Once the wire chases are ready, you should proceed to cut out pockets for the electrical wall boxes. Be sure to cut the pockets to the correct size, which will vary depending on which type of wall box you purchase.
Three Choices of Tools
You have three options for cutting ICF foam when running your wiring and installing electrical wall boxes:
- Use a hot knife: This is a quick and handy way to make accurate, mess-free cuts through the foam board. However, be warned that hot knives can be a bit pricey and they cannot cut through plastic webs.
- Use an electric saw: Electric saws are a bit messier than a hot knife, but still allow you to cut through foam with relative speed and ease. To make it even easier, embed a guide bolt at the 2” depth mark of the chain saw blade.
- Use a hand saw: This is your cheapest option that’s also quite labor-intensive and messy. If at all possible, avoid using a hand saw if you want to save time on cutting through the ICF foam panels and avoid cleaning up the resulting mess.
Four Tips for Installing Wiring Through ICF Walls
Below are four simple tips that will make your life easier as you run the wire chases through ICFs.
1. Use foam adhesive to keep wiring in place in the wall
The wire chases you install should be embedded at an appropriate depth in the ICF foam to be code-compliant. (Please check local regulations). Once the conduits are in place, you can use a foam adhesive to secure them there. You can simply spot-apply the foam adhesive right into the channels you cut out and that should do the trick of keeping the wiring in place.
2. Use an electrical box with a flange
There are several types of electrical boxes you can use when running wiring through ICF walls. The most common wall box types are:
- Metal wall boxes with holes at the back: These wall boxes are meant to be attached directly to the concrete wall.
- Plastic wall boxes with flanges: These boxes have a handy flange you can screw on to the ICF web.
Using an electrical box with a flange allows you to secure the box to the ICF wall’s web, which is a bit simpler and faster than drilling into the concrete.
3. Install the electrical box next to a web
If you’ve followed our second tip, you’ll have electrical wall boxes with flanges for straightforward attachment to ICF webs. The next logical step is to position your wall boxes such that they’re easy to screw directly to the webs. So, as you’re planning the wall box cut outs, be sure to make your cuts adjacent to a web whenever possible.
4. Install services that go through the wall before pouring concrete
Certain services will have to traverse from one side of the ICF wall to another. When dealing with services that penetrate the wall in such a way, ensure to install them before you pour the concrete. If you leave this task for later (perhaps hoping to get the job done at the same time as your wire chase channels), you’ll have to rent tools to bore through the concrete cores unless you already own that specialized equipment.
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Why Element ICF Is Best for ICF Wiring
Using Element ICF puts you far ahead in the game when wiring for two reasons.
As mentioned previously, Element ICF webs terminate ¾-inches from the top and bottom of the block. Consequently, when the blocks are stacked you get 1.5 inches of space between webs — that’s more than enough to cut a wire chase without having to slice through hard plastic, which is less messy, more efficient and can be done with a hot knife as well as a chain saw or hand saw.
Secondly, Element ICFs have thicker foam panels than most other ICF brands. Element ICF foam panels are a full 2 ¾ inches deep which allows you to embed a regular depth electrical box into the ICF foam without issues; most other ICFs do not allow this.
Wrapping It Up
Building with Element ICF gives you two immediate advantages when the time comes to install wire chases and wall boxes.
You don’t have to worry about the inconvenience and difficulty of cutting through plastic every 16” when you make the channels. Plus, the foam is extra thick and forgiving and thick enough to accommodate a regular depth electrical box.
That said, you can make your job even simpler by following the steps and tips we discussed above in our post. By sticking to these best practices, you’ll speed up the installation and keep the site as tidy as possible.
