ICF foundations are comfortable, energy-efficient, and easy to construct. But like any part of a building, ICF foundations come with certain nuances you must consider while planning, designing, and after your crews’ shovels hit the dirt.
In this post, we’ve consolidated all the advice we could give anyone who’s embarking on an ICF foundation project. In the guide below, you’ll learn the key things to consider as you plan an ICF foundation and give you a few handy tips for the design and construction phases.
Big Picture Planning Considerations For ICF Foundations
Here are three key big picture planning considerations when you’re building an ICF foundation.
How Do You Want To Use Your Basement Space?
Before you start working with a designer, take the time to consider what you will do with the ICF basement space.
Considering the mechanical and storage elements will consume up to 50% of the basement floor area, you’ll be left with 50% (or more) of the basement at your disposal.
ICF basements make for exceptionally comfortable living spaces, so you should explore different options for using your basement as an occupied part of the home. Your options include:
- Use the basement as additional living space. Doing so lets you relocate some of the planned living areas to the basement and thus shrink the overall footprint of the home.
- Use the basement as a recreational space. You can also plan a gym, hobby, or entertainment room down in the basement while keeping the living and sleeping quarters upstairs.
- Convert the basement into an office. Nothing beats a 2-minute downstairs commute to a private, secluded working space that’s still connected to your primary dwelling.
- Convert the basement into an Accessory Dwelling Unit (ADU). You can convert the remaining basement space into a fully functional, separate dwelling unit and generate rental income or house extended family members.
As you can see, the options are abundant; consider them before the design team gets to work to get the most out of your ICF basement.
Do you want to build your Above-Grade Walls With ICFs?
ICF works just as well in above-grade applications. Above-grade ICF walls are highly energy-efficient, disaster-resilient, and easy to install. If you’re building an ICF foundation and basement, consider upgrading your above-grade walls to ICFs, too.
Contact an Element ICF Dealer Early in the Planning Stages
If you’ve chosen to build an ICF basement, you should speak with an Element ICF dealer as soon as possible. Element dealers have vast experience with ICF construction in the area, so they’re an invaluable resource in the planning stages of any project involving ICFs. Your Element dealer will help you with a preliminary cost estimate, recommend quality installers, offer design tips, and walk you through any questions you may have. You can find a nearby Element ICF dealer here.
Important Design Tips for ICF Foundations
The following are vital tips and considerations for the design and construction phases of your ICF foundation project.
Design the Basement Height to 9’ 4”
Consider opting for a basement height of 9 feet 4 inches.
Designing an ICF wall to a height of 9 feet and 4 inches allows you to use seven courses of standard (16-inch high) Element ICF blocks without any field-cutting, half-height blocks, or height adjusters.
All of the latter options allow you to construct an ICF wall to any desired height but are obviously a bit more labor-intensive and less straightforward than simply stacking 7 courses of the blocks.
Use 32” Corner Jogs if possible.
Go with 32-inch corner jogs if possible. 16-inch jogs also work, too, but stay away from 1-foot jogs at all costs.
Use Element Resources to Plan Steel Reinforcement Placement
Use the Element One Minute Engineer or our Element Prescriptive Tables as guidance for the steel reinforcement placement within the ICF blocks. Local building regulations in some locations may have more onerous requirements, so always refer to the local codes, too.
Find ICF-Experienced Engineers
If you don’t have one already, take the time to find an ICF-experienced engineer or designer. You can find a skilled, ICF-experienced engineering professional here.
How to Get an ICF Basement Cost Estimate
To get a handle on costs, start by getting a quick and dirty materials estimate by using the Element Minute Estimator.
Your local Element dealer can give you a precise cut list and product pricing.
Only your ICF installer can give you firm, accurate estimates for the ICF foundation scope of work they will provide.
Important Installation Tips for ICF Foundations
Your ICF Footings Must Be Level
The footings must be extremely level when you’re building ICF foundation walls. Acceptable and workable tolerances are no more than ¼ inches — tell your installer this before they proceed with the footings.
If the footings are not sufficiently level, you’ll; struggle to erect the ICF blocks properly on top of them.
ICF Basement Walls Should Take a Week to Complete
Assuming you’re working on a regular-sized single-family home, it’ll usually take about a week to install an ICF foundation — once the footings are in place.
Find the Right Bracing
Conventional ICF bracing is ideal when building any ICF walls, but it may be in short supply in your location. Contact the local Element ICF dealer and ask them about alternative bracing options — they’ll recommend a suitable solution for your project.
Install a Protective Layer Over Waterproofing
The waterproofing membrane you apply to the exterior face of the ICFs is prone to damage and penetrations, and installing a protective layer over the waterproofing is your best insurance against future leaks.
Halo’s Subterra is a cost-effective, tough rigid insulation product that serves quite well as a protective barrier for the waterproofing membrane. It also adds more thermal resistance to the ICF foundation wall.
Plan For 6 Inches of Drainage Material
You’ll need to place at least 6 inches of drainage material over the weeping tile when you install the ICF foundation walls.
You’ll Need a Thermal/Ignition Barrier
To obtain your occupancy permit, you will have to drywall the interior basement walls.
Plan for this eventuality.
However, bear in mind the drywall does not have to be taped and sanded, nor does the electrical have to be installed. The drywall just needs to be screwed to the walls for you to get your permit.
Wrapping It Up
Building ICF foundations is a simple, straightforward task that rewards future homeowners with energy-efficient, comfortable basements.
However, if you’ve never built ICF basements before, it pays to learn some of the requirements that are specific to this construction method.
We hope that our guide has provided enough information to help you streamline the planning, design, and construction phases of your ICF foundation project.
And if you have any more questions before your project gets underway, be sure to speak with your local Element ICF dealer.
