Search results
Results From The WOW.Com Content Network
Insulation requirements for slab-on-grade floors can be found in section R402.2.9 of the 2012 IECC and section N1102.2.9 of the 2012 IRC. Both codes state, “Slab-edge insulation is not required in jurisdictions designated by the building official as having a very heavy termite infestation.”
This brief provides an overview of slab-on-grade insulation requirements, insulation protection, and flashing.
Slab-on-Grade Insulation Requirements in ASHRAE Standard 90.1. Let's unpack the issue in the context of ANSI/ASHRAE/IES Standard 90.1 - Energy Standard for Buildings Except Low-Rise Residential Buildings. First, the standard defines two classes of slab-on-grade:
Consistent with the 2009 IECC, slab edge insulation is only required for slab-on-grade floors with a floor surface less than 12 inches below grade. Slab insulation shall extend to the top of the slab to provide a complete thermal break.
Slab insulation is usually required only around the perimeter of the slab, but the 2018 IECC added a new requirement for full under-slab insulation of heated slabs. It is not clear, even using the ASHRAE reference, how to calculate F-factors for such slabs.
Yes, you can build a slab on grade foundation in the fall and leave it till spring if it has been properly protected against frost heave, though it will most likely require additional insulation. I would suggest you consult with the engineer who designed it.
Insulation is included in slab-on-grade construction for two purposes: Insulation prevents heat loss in winter, and heat gain in summer. This effect is most pronounced at the slab perimeter, where the slab edge otherwise comes in direct contact with outdoor air.