Comparing Insulation Weaknesses
Fiberglass Insulation - Cellulose Insulation - Prodex Total Insulation - Rigid Board Insulation - Spray Insulation
Alias(s): Fiberglass Batt Insulation, Fiberglass batts, batts, "the pink stuff"
R-value per Inch: Approx - 3.2
Weaknesses: Warning label reads: "WARNING PRODUCT SAFETY INFORMATION. Possible cancer hazard by inhalation. Can cause respiratory, skin and eye irritation. CAS NUMBER 65997-17-3, Fiber Glass Wool Product FBG-008CA December 1, 2001. PRECAUTIONARY MEASURES Avoid breathing fiber glass dust and contact with skin or eyes. Use a NIOSH-certified disposable or reusable dust respirator (certified N95 or higher). Wear long-sleeved, loose-fitting clothing, gloves and eye protection. Wash work clothes separately from other clothing; rinse washer thoroughly..." Not very air tight and is therefore s subject to air movement around the batts. It has low r-value per inch in narrow cavities. The brands that contain formaldehyde off gas over time. It itches like crazy during install. It is nesting material for rodents. It is difficult to cut fiberglass insulation to fit around electrical boxes and wires. High humidly will effect the r value of fiberglass.
Condensation in metal buildings and polebarns will make fibers wet, create mold, mildew behind the white vinyl surface. The dampness will reduce the effective R value of fiberglass insulation. This insulation type not address the radiant heat problem in metal structures.
Alias(s): Blown in Insulation
R-value per inch: Approx - 3.5
Weaknesses: Problems can occur relating to the distribution of the cellulose. In time it can be difficult to maintain an even distribution of the cellulose. A typical problem is that the insulation slides down from the center peak of house towards the edges. You're left with little or no insulation along middle of house ceiling. Not very air tight, air can flow through the insulation especially when coverage is light. Fibers can cause indoor air quality problems (rare). Good nesting material for rodents. Once wet it is permanently damaged. It does not dry quickly. Metal corrosion problems have been attributed to boric acid (fire resistant chemicals) leaching out of wet cellulose.
Prodex Total Insulation
Alias(s): Prodex AD5, Prodex Thermic
R-value: 15.67 (details).
Weaknesses: R value of the system will vary depending on the airspace size and direction of heat flow.
Rigid Board Insulation
Alias(s): Polyisocyanurate, polyiso board
R-value per Inch: 6 - 7
Weaknesses: Expensive, r-value diminishes slightly over time especially if the foil face is removed. It will absorb moisture if wet, degrades in sunlight. In cold weather, warm inside air containing water vapor can get past the wall finish and insulation, condensing inside the colder wall cavity. In hot, humid climates the same thing can happen, just in the reverse direction. Humid outdoor air in the summer can condense inside cool, air conditioned wall cavities. If enough of this happens and the water cannot escape, wood rot, mold, and other moisture-related problems can occur.
When insulating a foundation you need to consider that, although insects don't eat foam board, they can easily tunnel through it. Insect burrows reduce the r-value and structural integrity of the insulation. For these reasons, some manufacturers treat their foam products with an insecticide, usually a borate compound. Many building jurisdictions also mandate treating the earth around the building with insecticides. These jurisdictions may also want an inspection area several inches wide and all around the foundation of a house kept bare of insulation board.
Alias(s): Open-cell polyurethane foam, open-cell, soft foam, half-pound foam
R-value per Inch: 3.5 - 4
Weaknesses: More expensive than batts or cellulose. It will absorb moisture. Not DIY friendly. Installation produces excess foam that must be trimmed and disposed of. Ongoing debate in industry about fire resistance in exposed applications. It is subject to minimum and maximum temperature restrictions during installation.
Alias(s): Closed-cell polyurethane foam, closed-cell, hard foam, two-pound foam
R-value per Inch: 5 - 6.8
Weaknesses: expensive, not do-it-yourself friendly, ongoing debate in industry about fire resistance in exposed applications, installer experience/training critical as improperly installed foam is prone to failure, subject to minimum and maximum temperature restrictions during installation.
Alias(s): Kit foam, can foam, DIY foam
R-value per Inch: 5 - 6
Weaknesses: Expensive especially if used for large areas. Not user friendly- requires know how to both select the right product and install it properly. It is subject to minimum and maximum temperature restrictions during installation.
Alias(s): Wet spray cellulose, spray cellulose, dense pack cellulose ("dense pack" is an incorrect term often used to describe wet spray cellulose, see "dense pack" under injected insulation)
R-value per Inch: 3.5
Weaknesses: Not do-it-yourself friendly. Installed wet and concerns about moisture release and mold have surfaced in the industry. Adhesion to wall surfaces can break down over time so the tight installation may not be long term.