Are you building an ICF home with an attached wood-framed garage? If so, you may be wondering whether to design the garage with a conventional or ICF foundation.
This post will walk you through 3 different approaches that you can take for the foundation of your wood-framed garage that is attached to an ICF home. You will also learn how Logix XP-1 can be very elegant solution that can be employed in this situation to give you the best of both worlds.
How Should I Design the Foundation to a Wood-Framed Garage Attached to an ICF Home?
You have 3 ways of doing so:
- Build your garage with a conventional, in situ foundation
- Use an ICF foundation, then frame around the resulting foam curb
- Use an ICF foundation with Logix XP-1 blocks at the top course
Now, let’s examine each of these approaches in-depth.
Option 1 - Design the Garage With a Conventional Foundation
You can always use a conventional, cast-in-place concrete foundation beneath your wood-framed garage. If you opt for this solution, beware of the hassle of calling a separate forming crew and the greater potential for trade conflicts and scheduling delays.
Also, ensure proper design for the interface between the concrete garage foundation and your home’s below-grade ICF walls. Things can get a bit tricky with rebar connections, so your plans will benefit from an ICF-experienced engineer review.
Option 2 - Continue the ICF Foundation Under the Garage, With a Wood-Frame Above Grade
Do you want to get the work done quicker and with one less subcontractor to worry about? Then an ICF foundation for your garage is the better way to go.
That said, this option comes with challenges of its own.
For one, because the wood-framed above grade wall is thinner than the ICF foundation wall, you’ll end up with a foam curb along the foundation perimeter inside your garage. You can either leave this foam exposed or frame around it with plywood. The former isn’t ideal, while the latter solution is more sensible but also awkward. You’d have to rip the plywood sheets to roughly 8-inch segments to conceal the foam, then still cap it off at the top.
But that’s not all—the resultant curb will intrude on the floor area of your garage. To counter this problem, you’d have to oversize the footprint of the entire structure.
The good news is that there’s a way you can avoid all these hurdles. With Logix XP-1 blocks, there’s a 3rd, better option that lets you frame the above-grade garage walls flush with the ICF foundation.

Option 3 - Continue the ICF Foundation Under the Garage, but With Logix Xp-1 on the Top Course
Logix XP-1 is a one-sided ICF. Used with 4’x8′ plywood forms during construction, Logix XP-1 leaves you with ICF on the exterior and exposed concrete on the interior.
The 3rd option we’re looking at entails building your garage foundation’s top course with Logix XP-1 instead of the traditional 2-sided ICFs. This approach lets you build an ICF foundation, but with exposed concrete on the interior. Because there’s no foam panel on the foundation’s interior face, you can pour your slab right up to the concrete wall. Then, you can frame the wall above flush with the concrete wall below. And don’t fret – the XP-1 will interface seamlessly with your regular Logix blocks below.

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Wrapping it Up
If you’re attaching a wood-framed garage to an ICF home, the most practical and straightforward approach is to design it with an ICF foundation. That said, you’ll need a specialty ICF component, like Logix XP-1, to avoid the foam curb around the interior perimeter of the garage. By choosing Logix XP-1 one-sided insulated forms, you can:
- involve one less subcontractor in your project
- pour the garage slab right up to the top of the exposed concrete wall
- leave no foam exposed
- avoid having to oversize your garage’s footprint—this is notably beneficial if tight lot lines constrain your project

If you’re building a wood-framed garage that will attach to an ICF home, Logix XP-1 is your most hassle-free method.