John D’Annunzio
The Energy Crisis (as it was labeled) in the United States in the late
1970s initiated the wide spread installation of above deck thermal insulation
boards on low-slope roof systems. Prior to that time insulation was used in
specific regions of the country and primarily as a substrate for built-up roof
applications. Oil shortages drove up heating costs and the industry started to
investigate energy savings through the use of thermal insulation.
Polyisocyanurates and Polystyrenes were introduced to the commercial
low-slope market in the eighties and many federal and state facilities
(schools) began requiring that higher R-value insulations be applied on their
facilities. There were unwritten rules as to specific R-values, however these
were largely voluntary measures and were not actual code requirements.
That has changed. The new Energy Codes – which are becoming part of local
and federal building codes – are specific as to the required R-value of the
insulation system on low-slope roof systems. This will have an impact on all of
the low-slope roof systems that you design, so you should be aware of these
requirements and specifically how they are regulated in your area.
Below is the code interpretation of the 2009 International Energy
Conservation Code relating to low-slope commercial facilities:
This code establishes the minimum
R-value required for insulation above the deck on commercial buildings. The
thermal R-value required for insulation applied entirely above the deck is
based on climate zones in the chart listed below. The code indicates that the
thermal R-value prescribed is for the insulation only and does not include
other building materials or air films.
TABLE 502.2(1)
BUILDING ENVELOPE REQUIREMENTS – OPAQUE ASSEMBLIES
ROOFS
INSULATION ENTIRELY ABOVE DECK
Climate Zone R-Value
1
15
2
20
3
20
4
20
5
20
6
20
7
25
8
25
No comments:
Post a Comment