Modifications in the International Energy Conservation Code (IECC) could increase competition for US wood panel producers from foam sheathing, reports Random Lengths.
The 2012 version of the code requires that houses in certain climate zones must be built with 2×6 framing, traditional insulation, and an inch of foam sheathing.
Foam sheathing provides a full insulation envelope and moisture resistance while a typical wood-framed house has a moisture barrier, but wall insulation only in the cavities between framing.
However, foam sheathing lacks a nail base for siding, which means siding must be anchored to the framing.
It has substantially less market share than plywood or OSB in residential construction, but provides greater insulation properties and a higher R-value than wood sheathing.
