Cascade Built Blog
June 5, 2008
ICFs Insulated Concrete Forms
Posted by admin, 5:08 PM
A little out of sequence, but I wanted to share photos and my observations of the use of ICFs on the Alley House project, a current Cascade Built single family sustainable project in Seattle.
The site is quite small, only about 2000 SF, 40′ by 50′. The site slopes 9′ , so we have a large retaining wall and the first floor is daylit only on the east and north facades, the rest is underground. That left us with 3 10′ retaining walls along the N, W and S sides.
The engineer specified that the metal track for the ICF be secured along the footing edge. It is fastened with a concrete nail. The nail cracked the still green concrete in a couple places (as you might predict) so the track wasn’t 100% secured. During the pour, a panel at the bottom broke out of the improperly secured track system and we lost some concrete at that point and caused costly delays during the pour while the crew fixed the blown out panel.
Otherwise the system is pretty easy to deal with. It would be suitable for a homeowner doing a small foundation, as it clicks together and the rebar rests in the clip system easily. I’m not entirely sure that the ease of use is a benefit to contractors. Not having to strip forms is only a minor advantage. However, the resulting foundation is quite stout, and pre-insulated, so there’s no need to fir it out on the inside and add insulation. It is completed already.
