Icynene insulation has pluses, minuses

By Dan Cabot - October 12, 2006

Builders, architects, and their clients who are considering using light-weight Icynene foam insulation will find that it has many advantages over other forms of insulation. The manufacturer claims that using Icynene will create a healthier, quieter, more energy-efficient home. However, it is expensive and may require that the building be equipped with an advanced ventilation system.

The advantage of whole-house Icynene insulation is that it seals the building completely, eliminating drafts, and therefore cuts heating and cooling costs in half as compared with fiberglass insulation, according to Howard Marlin, sales manager for Foam Insulation Technology, Vineyard distributor of Icynene. The lower heating and cooling costs would also be reflected over time in significant reductions in the use of fossil fuels.

Icynene also has superior sound-deadening qualities, according to Mr. Marlin, greatly reducing noise from outside the building and even muffling echoes within it. Unlike other forms of insulation, Icynene allows water vapor to escape, preventing the formation of damp areas within the walls where mold might form. It will break down if subjected to high heat, but will not itself sustain a fire if the heat is removed. It is itself inert, giving off no noxious gasses.

The manufacturer describes Icynene foam as having the consistency of angel-food cake or sponge cake. To The Times, it felt like a pastry shell meringue, light and yielding, a bit crunchy. It is much softer than the heavy and stiff polyurethane foam with which it is sometimes confused. One can walk on bats of heavy foam insulation, and the material is too stiff to conform completely to the spaces in which they are placed. Icynene fills the cavity completely but is flexible enough that wires or pipes can be pushed through it for later modifications, Mr. Marlin reports.

Icynene is sprayed into the walls and ceilings, where it expands 100 times its volume, filling the spaces and caulking them at the same time. It sets in seconds and its slight odor, which Mr. Marlin describes as not unpleasant, dissipates in 24 hours.

Costs versus benefits

Homebuilders considering Icynene will have to balance the benefits claimed by the manufacturer with its drawbacks.

The first stumbling block is price. According to Mr. Marlin, Icynene runs about the same price as Cellulose, or about three times the price of standard fiberglass insulation. An off-Island builder reported to The Times that Icynene installation in his own home actually cost more than four times as much as fiberglass. Mr. Marlin presented the following chart for an 800-square-foot guesthouse in West Tisbury:

If Mr. Marlin's figures are correct, the Icynene would return the extra cost (about $5,000) in six or seven years, assuming the home were used year-round.

A second problem is a side effect of the Icynene's sealing properties. A house wrapped in Icynene is completely caulked, almost airtight. In the coldest winter weather, when all the windows are closed, the building will have to be artificially ventilated. In order not to lose the heat-saving advantages of a tight building, the ventilation system may have to include air exchangers to warm the incoming air. Mr. Marlin does not see this as a drawback. He says that the motto of the industry today is, "Insulate tight, ventilate right," and he cites endorsements from the American Lung Association, This Old House, EarthCraft House, and The New American Home.

Icynene insulation might be an important step toward the reduction of Vineyarders' dependence use of off-Island sources of energy - if homeowners decide the cost is worth the benefits.