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Cementitious Foam Insulation Gets a Second Look


Air Krete® cementitious foam insulation has been around for decades. Air Krete, for those unfamiliar with it, has the look and feel of shaving cream as it's injected into walls, ceiling or roof cavities. When dry, it cures into stable, lightweight solid foam.

At R 3.9 per inch, it's more effective than fiber insulations, like fiberglass and cellulose. It is even as effective as several of more expensive spray foam and rigid board insulations. Like other types foam insulation, it seals as it insulates, slowing up energy loss in two ways: resisting the movement of heat by conuction and stopping air leaks.

Unlike messy polyurethane-based foams, Air Krete doesn't rely on a solvent-based chemical process. It's made up of air, water, and magnesium oxide (MGO) and is completely non-toxic. No hazardous fumes are produced during or after application, so homeowners do not need to vacate their homes for hours or days while it cures, as they do with polyurethane-based foams. Cleanup is with water. In fact, spillage washes off siding with water and is harmless to garden plantings, lawn, or pets. Nor is there any off-gassing of VOCs, such as formaldehyde, during the life of the product.

Air Krete doesn't expand or heat up

Air Krete is especially well suited to retrofit applications. Many 2-part foams can't be sprayed into a finished wood-frame wall because pressure generated by expansion will cause the wallboard to bow or even pop off the framing. Air Krete is non-expanding. It's designed to flow and fill around electrical wires, outlet boxes and, if there are any, old underperforming insulation batts.

Unlike standard 2-part spray foam insulation, Air Krete won't heat up upon application, so there is no potential for excess heat generation. Polyurethane sprays foams, on the other hand, have been known to char, smolder or ignite when installed improperly. Air Krete won't burn even during a house fire.

Being water based, Air Krete does take longer to cure than other foams. Ventilation guidelines, including leaving the access holes unplugged, ensure reasonable dry times. It is also essential to avoiding spraying Air Krete between vapor barriers. In some cases dehumidification may be recommended to speed the curing process.

What about shrinkage?

Shrinkage is a question that comes up when any insulation is installed in a wall, ceiling, or floor cavity. After all, if insulation shrinks (or settles) after installation, its ability to resist heat flow and to stop air leaks is compromised. Because it's inside a closed cavity, shrinkage is difficult to detect. Unlike several other types of foam insulation, tests show that Air Krete will not shrink as long as it is injected into an enclosed cavity. Injection into an enclosed cavity allows the foam to be slightly "pressurized." In an open cavity, pressurization is not possible, and slight shrinkage may result.

Air Krete Benefits

  • Resistant to mold growth, even at high relative humidity.
  • Maintains a high insulation value over time. (R = 3.9 at 2.07 lbs/ft3)
  • Seals effectively around the edges, preventing air infiltration.
  • Does not expand or settle and completely fills cavities, including around obstructions and crevices.
  • Does not inflict damage to the environment or humans. Material is non-toxic, does not create any ozone-depleting CFC's and does not contain any formaldehyde or carcinogenic fibers. In fact, it actually absorbs carbon pollution from the atmosphere!
  • Does not burn or release any smoke. In fact, it may be used as fire-stop material.
  • Has a de-oiling effect that deters rodents and insects.
  • Is fully recyclable and can be used to enrich soil.
  • May be used in wall, roof and ceiling cavities, in new or old construction.
  • Very cost-effective.
  • Serves as a soundproofing material and may be used inside interior sound partitions. When plumbing pipes are encased, water noises are significantly reduced.
  • Because Air Krete is made of Magnesium Oxide (MGO), a refractory cement, it is ideal for high temperature applications.

HomePro Match is home to a network of qualified insulation contractors that can help insulate your home, create more energy efficiency, greater indoor air quality, and comfort for the residents. Touch base today for a consultation!

Article originally published on MyHomeScience.com

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