Retrotec USACE User Manual
Page 137
Appendix D D7
D.1.2.2 Poor Flat Roof Insulation (Waste)
Figure D10. Flat roof with a low insulation level.
Many older fl at roofs (Figure D10) have excessive heat losses and gains due
to roof low R-value, resulting in increased sensible load on heating and cool-
ing systems. They also have a chronic water leak problems. When fi xing leaks,
consider adding roof insulation.
D.1.2.3 Metal Roof Painted with a Low Refl ective Paint (Waste)
Figure D.11. High metal roof surface temperature due to the use of low refl ective paint. Pictures are taken at the outside air
temperature equal to 93 °F.
Excessive building cooling loads can result from the installation of metal roofs
painted with a low refl ective paint. In hot and mild climates, consider instal-
lation a refl ective “cool” roof (Figure D11). Information on Energy Star re-
fl ective roof products is available through http://www.energystar.gov/index.
cfm?c=roof_prods.pr_roof_products.