Recently, there has been much conversation about the values and types of Insulation. At Sustainable Design, we are not locked in with any one type of insulation, however, there are certain more desirable types we would recommend over another.
This brings up the issue of exactly what a sustainable residence is all about, which we will cover later at more depth. For the time being let us just focus on insulation and building performance.
Insulation materials—used to reduce heating or cooling loss through the exterior of the structure or to unheated or uncooled areas within the structure—are rated for thermal resistance, expressed as the material’s R-value. The higher the R-value, the more effective the insulation. Higher R-values usually translate to higher costs for materials. Consult the architecture plan views, elevations, sections, and details that provide the location of the materials. In addition to the building envelope, insulation information can be found on building sections, wall sections, and details, particularly on the sections through the exterior envelope of the structure. The specification should also be reviewed for product information that may provide pricing criteria.
Insulation is available in various forms, sizes, thicknesses, and R-values. In wood and light-gauge metal frame construction, blankets or rolls of insulation, called batts, are installed between the studs or joists at the exterior walls, roof, or floor of the structure. Insulation is available with an attached paper or foil facing that acts as a vapor barrier. Rigid insulation is used where a particular shape must be maintained, such as under concrete slabs, structural insulated panels, at the exterior of foundation walls, for roof decks, and over exterior sheathings under siding materials. Some common types include expanded polystyrene, of called “beadboard,” and extruded polystyrenes, such as Styrofoam. More complex rigid insulations used as part of roofing systems are called polyisocyanurates. These are faced with asphalt-impregnated felts, generally have a high R-value per inch of thickness, and are a common component in flat roof systems.
Additionally, there are natural wool products, recycled products of various types, and a whole plethora of commonly available materials. For the purposes of this article, we will stay focused on the most common type of home insulation, batt. In that it is the easiest to obtain and install, we have listed a few basic items to consider when purchasing batt insulation.
Taking off Quantities
Batt or roll insulation is taken off and estimated by the square foot, and should be listed separately according to the following:
• Width
• R-value
• Location within the building (e.g., roof, walls, floors, etc.)
Materials should also be listed separately by vapor barrier facings, such as kraft paper and foil facing. Consult the specifications for the required R-values and specific product information.
Always remember you can never have too much insulation. For more information contact our office and we will send out one of our inspectors to give you more information on how you can save money and make your home more comfortable and valuable in the long run.