Wondering what NBCC 2020 has in store for ICF builders?
The 2020 code update, which was initially scheduled to go into effect in December of 2020, was postponed several times and is finally rolling out in 2022.
So, we’ve asked Ross Monsour, director of the Insulated Concrete Form Manufacturers Association and member of the National Building Code Standing Committee, for clarification on the new clauses surrounding ICF regulations.
With Ross’s help, we were able to demystify the most substantial changes in NBCC 2020 and will walk you through them below.
2020 NBCC Changes to Insulated Concrete Form (ICF) Construction
Canada’s building code gets developed and revised by the Canadian Commission on Building and Fire Codes, in conjunction with standing committees, task groups, and workgroups from various sectors of the building industry.
The changes to regulations surrounding ICF construction followed a similar path, being drafted based on a consensus between different construction industry members.
According to Ross, these most recent changes were also fully supported by the Canadian Homebuilder’s Association. And, as Ross explains, these much-needed revisions have been long in the making and are primarily focused on standardizing ICF construction regulations, which have so far been handled on a case-by-case basis in the field.
Below is the summary of these changes to the NBCC.
Change #1 — Adoption of a Material Standard for Flat ICF Walls
This is the most significant change, thanks to which there’s now a code-accepted standard for various materials that comprise ICF walls — CAN/ULC 717.1. The standard provides specifications for the following materials:
- Webs that separate the foam panels and hold the rebar in place
- The foam that comprises the ICF panels on each side of the concrete core
- Shear strength of webs related to the concrete pour
Thanks to this change, building inspectors no longer have to assess the materials specifications to determine the products manufacturing and plant quality control.
Change #2 — Above-Grade ICF Walls Allowed For 3-Storey Residential Structures
Another critical modification to the code removes the 2-story constraint for flat ICF walls in Part 9, residential occupancies. So, whereas earlier versions of the building code limited above-grade ICF walls to two stories, now builders have the option of building up to 3 stories, with a maximum floor-to-floor height of 3 meters.
Likewise, the code change does away with restricting the number of dwellings in Part 9 ICF buildings (they were previously limited to a single residence).
Change #3 — Rebar Equivalence
Once the 2020 code goes into effect, builders will no longer be limited to using only 15M rebar dowels for lateral support at the bottom of ICF foundation walls. Thanks to the change, there will also be an option to use 10M rebar with narrower spacing; this is welcome news, since 10M bar is more typical in the field and is easier to handle. Here are the new code’s rebar and spacing requirements for lateral reinforcement of foundation ICF walls:
- 15M rebar dowels spaced no more than 1.2 m on center
- 10M rebar dowels spaced no more than 600 mm on center
Change #4 — Clarification of Lateral Support Requirements
Whereas older code versions left much ambiguity about lateral support requirements for the tops of ICF foundation walls, the 2020 code finally has some firm answers to builders and building officials alike.
In addition to the existing wording, the new version of the code clarifies that flat ICF walls will be considered laterally reinforced, if:
- They support a solid masonry superstructure OR an ICF wall.
- The foundation wall extends no more than 300mm (11.8”) from the footing to the finished grade condition, and the difference between grade levels on each side of the wall doesn’t exceed 150mm (5.9”).
Change #5 – Attachments for Exterior and Interior Cladding
This code change will reflect the current practice of using specific types of fasteners for interior attachment of gypsum and exterior cladding. In the past, some building officials have challenged the use of fasteners in the plastic webs, both inside and outside. These changes will no longer require engineering stamps if questioned in the field, but rather offer options and spacings, which will vary by region in Canada.
Why These Changes Matter
These changes are of consequence to ICF builders and developers for two key reasons.
For one, they allow greater flexibility when building Part 9 residential structures with flat ICF walls. We can now build taller buildings with ICFs, there are more lateral support options, and the latter are finally defined with some degree of clarity.
Secondly, the code changes finally specify compliant materials for ICF walls. This means that a project’s engineering team, in reviewing a building permit will no longer have to require engineering stamps on many of the many issues related to constructability of ICF walls. This lifts a major financial burden off the builders’ shoulders and streamlines the permitting process.
Note that the ICFMA has produced the ICFMA Prescriptive Manual, which relieves the requirement for engineering stamps for Part 9 structures within the document’s scope. Just released in March 2021, it has had good uptake by the industry in general and was well-received by building officials. The ICFMA will put the manual forward for inclusion in the 2025 NBCC, as a model of good engineering practice.
Wrapping It Up
After what seems to us to be a long wait, the NBCC is finally standardizing ICF construction.
While many aspects of building with ICFs remain undefined, now builders have a defined standard for many of the basics, like materiality, exterior and interior attachments, and lateral supports.
This means that building with ICF will be further simplified once NBCC 2020 takes effect.