The average price to cover 200 square feet with a foam insulation kit will run between $300 and $600 (about two to three kits). Inside these kits is something called Icynene, a foam made from two liquids that are heated and pushed through a gun on the can. When Icynene is released, it expands up to 100 times its size as it hits the surface area you're covering. These can contain a lot of gasses, making its installation a dangerous process. Even low-pressure sprayers can be harmful to homeowners' health.
Spray polyurethan foam does effectly prevent all six of these heat transfer methods from occurring. These should be the mechanisms by which you judge insulation, in addition to their R-Value. If you're uncertain about installing spray foam insulation, Energy Star has a map that recommends levels of insulation by R-value and cost-effectiveness in the United States.
The problem was that the installer was doing his first spray foam job ever, and the thickness of the insulation varied from zero (visible roof deck) to about 9". Unfortunately, good average thickness doesn't cut it. The coverage needs to be uniform because a lot of heat will go through the under-insulated areas. (See my article on flat or lumpy insulation performance.)
United Coatings™ Roof Coat Elastomeric Coating is an effective coating for providing long-term reflectivity over a wide range of roofing substrates. The high reflectivity of Roof Coat Elastomeric Coating keeps the roof substrate cool, which not only helps prolong its longevity but also helps save on energy costs. Roof Coat Elastomeric Coating’s rich consistency uniformly covers the textured profile of various substrates, forming a flexible monolithic membrane that provides protection from normal weathering, aging, and ultraviolet exposure.
In general, cantilevered steel beams are a nightmare. If part of the steel beam is in contact with exterior temperatures, then it's best if the interior portion of the steel beam is covered on all sides with insulation. This is generally impossible (because the interior portion of the cantilevered beam generally supports a load, meaning that you can't wrap the steel beam in insulation on all sides).
I used this product to seal and insulate my rim joists as I am finishing the basement. The builder used R13 batt insulation when we built the house 3 years ago. I use a dehumidifier to control moisture in the basement which is below grade. The setting I use is 55%. The dehumidifier kicks on periodically and requires emptying every few days. Since using the foam all around the house on the rim joists and sill plate, the dehumidifier has stayed at 50% for over two weeks since spraying and rarely turns on anymore. I also put the original R13 batt insulation back up after the foam cured.

When choosing a waterproofing and sealing product, we must see to it that we can easily use and apply it using simple tools, including a squeegee or a paint roller. With ease of application, we can be certain that we can achieve hassle-free application and smoother and more attractive finish than other products could give. So when reviewing the products we have featured above, we have made sure that they are easy to apply.

Roof Coating