Retrotec USACE - Manual (Page 140)

D10 ENERGY & PROCESS ASSESSMENT PROTOCOL
D.1.3.2 Poor Slab-on-Grade Insulation (Waste)
Poorly insulated concrete slab-on-grade fl oors cause signifi cant heat losses and
discomfort (Figure D15). Most heat losses are through the fl oor perimeter,
rather than through the fl oor and into the ground.
Existing slab-on-grade foundations are often insulated over the exterior of
the footing/slab edge; insulating under an existing slab is usually impractical.
Insulation on the exterior of the footing/slab edge reduces heat loss from both
the foundation and the slab. Sometimes a foamboard insulation is extended
outward beyond the foundation for several feet. This offers more protection
to the footing from freezing. It also allows the builder to dig a more shallow
footing without risking damage due to frost-heaving. All exposed parts of the
insulation must be covered with metal, cement, or some other type of mem-
brane to protect it from damage.
D.1.3.3 Floor Penetrations (Waste)
Figure D16. Unsealed interfl oor penetrations.
Unsealed interfl oor penetrations (Figure D16) result in air movement between
building spaces and outside air and thus in increased sensible and latent load
on heating and cooling systems. Appendix E includes further information on
air leakage pathways and their sealing.