c) Roof surface color has an impact on energy
consumption and membrane temperature and color should be
considered in the evaluation of energy and life cycle cost, and
when determining the suitability of the roof membrane.
Location. Roof insulation can be located either above
or below the roof deck. In low slope roof buildings, above deck
insulation is preferred.
Materials. A wide variety of insulation materials are
available for use as roof insulation in buildings. Each material
usually has a unique set of properties and compatibility with
other roofing components which must be properly evaluated so that
the roof will perform satisfactorily.
Board Insulation. This form may be either a single
component material or a composite of two or more different
Single Component Insulation
b) Composite Board Insulation. In order to provide
compatibility with certain types of roofing materials and also to
provide the desired fire rating, composite board insulation is
available, consisting of two or more pre-assembled layers of
differing insulation materials. Use of composite board
insulation often allows application criteria and thermal
resistance criteria to be met with minimum insulation thickness.
Insulating Concrete. Several types of lightweight
insulating concrete are available for roof insulation purposes.
They are typically installed over ventilated roof decks or
formboard on low slope roofs, since it is possible to slope the
concrete in order to provide roof drainage. The concrete must be
able to exhaust original mixing water to the interior space.
Also, refer to Section 2.
Sprayed Plastic Foam. Sprayed-in-place plastic
polyurethane foam insulation is available for roof insulation.
Refer to Section 7.
Properties. Physical property data are usually
available from the insulation manufacturer and often consist of
testing laboratory reports. Care should be taken that the data
reported are appropriate for the conditions under which the roof
will perform. Physical property data are also published in the