The Pacific Northwest is a challenging construction market. The local building standards are as arduous as the buyers’ demands thanks to the region’s vulnerability to wildfires and seismic activity. On top of it all, there’s an ongoing skilled labor shortage that has gripped the US West Coast long before the COVID-19 pandemic, and has only worsened since.
However, an innovative developer can still reap the rewards of the region’s pricey housing market — if they can handle the aforementioned challenges with an effective solution.
In today’s post, we’ll tell the story of Dave Gowers, an experienced structural engineer, who proposed ICF as an alternative to wood-frame construction in a new subdivision in south Oregon. Below, you’ll find out how building with Logix ICF helped the developer and his team mitigate the homes’ wildfire vulnerability, improve seismic resistance, and facilitate installation with non-expert labor.
Cave Junction Residential Subdivision: Project Background
The project Dave Gowers became involved in is situated in Cave Junction, a community in Southern Oregon. The development comprises an entire new subdivision of 60 homes with various floorplans.
Originally, all the homes were meant to be built with a wood frame and trussed roofs — the developer was not familiar with ICF construction. However, after Dave explained the benefits of switching to ICFs, the developer quickly saw how this system would solve many of the project’s challenges.
Project’s Primary Challenges
Like any development, the subdivision project in Cave Junction had several challenges with which to contend. Below are the key obstacles that stood in the way of the subdivision’s developer — as you can see, all of these complicate traditional wood-frame construction.
- Wildfire threat: Like much of the US Pacific Northwest, Cave Junction is situated in an area with a severe wildfire hazard. In fact, several noteworthy wildfires have ravaged the surrounding wooded areas in the past few decades. The most notable of these are the Slater Fire of 2020 and the Biscuit Fire of 2002. Given the exposure to annual threat of wildfire activity, homes in Cave Junction must be designed with some degree of fire-resistance to attract buyers.
- Seismic hazard: Seismic Design Category (SDC) D, which is the second highest category on the scale. Wood frame homes built in SDC D areas require significant shear panel walls and are restricted from having large openings.
- Shortage of skilled labor: Skilled labor, which is sorely needed for wood framed construction, has been in short supply for a while. With the COVID-19 pandemic, the availability of skilled labor plunged even further.
Overcoming The Challenges
Dave Gowers as well as the project’s developer were sufficiently convinced that converting the new homes to ICF construction would overcome the challenges.
Crucially, ICFs are fire-resistant. And while they’re not fire-proof, they offer enough resistance to advancing wildfire flames to either protect the home’s structure completely, or at least to keep the homeowners’ belongings inside safe. The same can’t be said for wood-frame homes, which are any firefighter’s worst nightmare.
Secondly, ICFs provide 9-10 times as much shear strength as a wood structure, thanks to the #4 rebar with which it’s reinforced and the superior shear strength of concrete. This added strength allows the designers to build thinner walls and create larger openings without worrying about sacrificing the home’s earthquake resistance. This means that the homes in the subdivision had more net floor area and larger windows than their wood-framed counterparts in the area.
Thirdly, ICFs are quite easy to install — even with smaller and moderately skilled crews – all it usually takes is some instruction and guidance from a skilled foreman or superintendent. Luckily, the General Contractor hired to build the subdivision (Dave Hoover Construction) had plenty of experience with ICF buildings.
With these benefits in mind, the project team opted for 6-inch ICF walls instead of the wood frame in all the subdivision homes.
The team also settled on Fortruss roofing instead of the originally intended truss roof system. The upgrade was not particularly expensive, and added only about 5% to the over construction costs. This was a relatively minor added expense considering the roof system’s added protection against wildfire flames and energy efficiency.
Wrapping It Up: ICFs Helped Overcome Wildfire, Skilled Labor, and Seismic Hazard Challenges
In conclusion, some of the subdivision units were pre-sold before construction finished. The promise of a wildfire-resistant envelope that’s also extremely energy efficient and seismically sound has been quite effective at attracting buyers. In fact, many of the buyers purchased both halves of the duplexes in the subdivision (and duplexes generally command a premium in the area).
But crucially, using ICFs also alleviated the skilled labor issue. Since ICFs are so easy to work with, and their installation doesn’t take long to learn, the crews were able to handle the task flawlessly with minimum supervision from an ICF-experienced GC.