It seems like it should not be so complicated.
Insulating concrete slab on grade.
From a radiant heating perspective it doesn t matter if the slab is actually at grade or is poured several feet below grade as part of a full foundation.
Yet slab on grade insulation can be arranged in a number of configurations each with pros and cons.
Martin holladay explains insulating a slab on grade in the energy smart details department.
Insulating a slab on grade depends on at least four factors.
Slab is one foot or less below grade r 10 insulation required extending 2 feet below grade for climate zones 4 and 5 4 feet below grade for climate zone 6 insulation should extend downward from the top of the slab with two options to reduce slab edge insulation r value.
Slab on grade construction technical guide deciding to build your home with a slab on grade foundation instead of a conventional basement or raised crawlspace foundation can greatly reduce your environmental impact during construction and has the potential to offer significant financial savings as well.
The climate the type of foundation whether the slab includes hydronic tubing for radiant heat and the severity of the local termite problem.