Knowledge

Insulation

Function

The use of insulation reduces fluctuations in interior temperatures, moderating heat loss and gain.

Insulation Placement

Insulation can be placed variously in four positions:

  1. Exterior covered by a finish surface as with EIFS (Exterior Insulation Finishing System)
  2. In the cavity between the interior and exterior wythes
  3. Integral to the wall by placement in the masonry cores
  4. On the interior, such as batt insulation between studs or as rigid sheets anchored to the backup structure

Insulation Types

One popular and effective form of insulation is expanded polystyrene, sometimes referred to as rigid foam insulation. Fiberglass batt insulation is often used in single wythe stud wall construction and is placed between the studs. Perlite, Styrofoam beads or cellulose loose fill can be poured or blown into the masonry unit cores.

R-Values & U-Values

R-value is the thermal resistance to heat flow by a building assembly. A greater R-value offers greater insulation. U-value is the reciprocal of the R-value (U = 1/R) and defines transmission of heat through a building assembly. U is expressed as BTUs per hour per one square foot of area. A greater U-value offers less insulation.