Fiber glass and rock and slag wool insulations are effective in helping reduce heat flow, reduce unwanted noise, and control moisture.
Insulation resists the flow of heat. Heat is a form of energy. By reducing heat flow in a properly insulated building, less energy is used for winter heating and summer cooling. Insulating today will help save both dollars and energy. Savings vary. Find out why in the seller's fact sheet on R-values. The higher the R-value, the greater the insulating power.
Insulation reduces sound transmission. An insulated floor, wall or ceiling will have an improved Sound Transmission Class (STC) compared to a similar building section with no insulation. As an example, 3-1/2 inches of fiber glass insulation in a wall can improve the STC from 3 to 10 points, depending upon construction details.
A vapor-resistant membrane (commonly called a vapor retarder) attached to batt or roll insulation, or installed separately, decreases the possibility of moisture vapor condensing to water within the structure.