Rigid Foam Insulation

Rigid Foam Insulation

Introduction

Rigid foam insulation can be used in a wide variety of building applications, both above and below ground.

Applications include walls, roofs, floors, foundations and doors, as well as under basement slabs or over slab-on-grade floors.

Rigid foam insulation provides two key building benefits:

• Energy efficiency

• Moisture resistance

While there are many different products on the market, there are three main types of rigid foam insulation: 

• Extruded polystyrene - a closed cell foam insulation with consistent density and therefore relatively high compressive strength; also highly resistant to moisture

• Molded polystyrene - a closed cell foam material, sometimes referred to as 'beadboard,' that can be manufactured at various densities for different applications

• Polyisocyanurate and Polyurethane - closed cell foams available as a liquid spray, poured foam and rigid insulation sheathing

Common terms for rigid foam insulation include foam plastic, foam board, insulated sheathing, rigid foam sheathing.

The Dow Chemical Company manufactures STYROFOAM™ extruded polystyrene insulation also know as Dowboard and BLUEBOARD™. Other brand names include THERMAX™, STURDY-R™, and TUFF-R™ from Dow.

Benefits

Rigid foam insulation offers building owners several key advantages:

• Energy efficiency - R-values of rigid foam insulation range from R-4 to R- 7 per inch of thickness, which is two to three times greater than other insulating materials of the same thickness. Installation of rigid foam insulation typically pays for itself within two years through lower utility bills, and keeps on paying a return to the homeowner throughout the life of the home.

• Moisture resistance - When carefully installed according to the manufacturers' instructions, rigid foam insulation helps control air infiltration more effectively than other types of insulation. This can help control moisture and mold growth.

• Easy to install - Rigid foam insulation is compatible with different building finishes, and can be easily installed without special equipment.

For more information, watch these videos.

Doug Bibee, Residential Technical Specialist, Dow Building Materials, explains the benefits of using insulated foam sheathing in to increase energy efficiency and help prevent moisture/mold problems.

Wood framing typically represents 25% of the surface area of walls, so the proper installation of insulated foam sheathing can prevent thermal bridging and increase energy efficiency in a house.

Insulating the exterior foundation walls helps the concrete stay warm and uses thermal mass properties to help keep the basement warmer. Find out how to install exterior insulated foam sheathing.

Installing insulated foam sheathing on the interior walls of a pre-existing basement helps prevent heat loss and moisture problems.

Source: Michigan Bureau of Construction Codes