Concealed Condensation

Concealed condensation is the most difficult to deal with and can be the most damaging to any kind of structure. This type of condensation may be controlled in metal buildings by the proper ventilation. Additional condensation control can be accomplished by venting the cold cavities of the walls and roof.

Insulating Against Radiant Heat

Traditional forms of mass insulation, like fiberglass, are effective in preventing heat transfer by conduction and convection, but they less effect on radiant heat. Between 80 and 90% of the radiant heat striking fiberglass will pass through or be "emitted". Radiant transfer typically has as much impact on the temperature in a building as conduction and convection. For more information on radiant barrier facings click here.

Facings

In addition to acting as a decorative protection barrier, facings serve an integral part of the overall insulation system. Facings provide vapor barriers, light reflectivity and structural strength. In some cases, a reinforcement of fiberglass scrim is used for extra rigidity and greater impact resistance.

The effectiveness of a vapor barrier depends on three primary factors:

1) Location within the insulated section

2) Permeance

3) Proper installation

Thermal Conductivity (K-Value)

A unit used to express the amount of heat, in BTU's per hour, that passes through one square foot of homogeneous material that is exactly one inch thick and has a temperature difference of one degree Fahrenheit between its surfaces. As the K-Value decreases, so does the amount of heat permitted to pass through the material.

Perm Rating

The perm rating, or permeance, is a measure of the amount of water that passes through one square foot of material per hour. The lower the perm rating, the more effective the barrier. A facing material with a perm rating of 0.1 or less is considered excellent. Anything with a rating above 1.0 is not considered a vapor barrier.