Choice of foundation wall: on Faswall and Durisol
I recently made a statement on another thread about my opinion of Faswall and Durisol ICFs as a poor choice for walls particularly in a cold climate. Like most of my opinions I'm usually failing to see all aspects of the issue.
For a foundation wall Faswall and Durisol ICFs seem like appropriate choices because of the amount of concrete they displace compared to foam ICF forms including the T-Mass wall. Also for a comparable core width you get some embedded R-Value were you get very little R-value from the concrete cores of the foam ICF forms, including the T-Mass wall (in fact the T-Mass wall seems to represent the most quantity of concrete). While foundation wall thickness is not a limiting factor with Faswall and Durisol you can still add insulation layers and achieve a higher R-value for a given width.
For the exterior a parge coat finish above grade seems sufficient.
The Durisol and Faswall forms are manufactured through some vague "mineralization" process of wood chips. I'm sure this has an embodied energy ramification and I wonder how it compares to concrete embodied energy.
It is still my opinion that because unit sizes of these ICFs can't be manufactured with smaller tolerances of dimensional difference that stacking them and maintaining level courses can be a challenge. A slight wonky wall below grade is easily hidden, but maintaining a level sill plate may be made difficult.
I'd be curious to hear others take on this.
Posted Feb 11, 2011 2:57 PM ET
Edited Feb 11, 2011 3:21 PM ET
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