The process by which heat energy in the form of light (usually IR unless the substrate is hot enough to glow in the visible range) is emitted more strongly by warm surfaces and absorbed by other materials especially those of low IR reflectivity (think matte black finish). Radiant heat transfer does not require a medium. Foam insulation materials, such as spray foam insulation, are opaque to thermal radiation, like most solid materials.
As this example illustrates, it's important to seal the envelope completely. One of spray foam's biggest selling points is its air-sealing ability, but it can't seal places where it's not sprayed. One of the nice things about using spray foam in new construction is that you can do a Blower Door test before the drywall goes in. Even better, you can test for leaks with a fog machine. http://youtube.com/e/ggLAUsiuI_o
One of the high-tech insulation products being utilized these days is a foam-spray product called "Icynene," which is a foam that starts as two liquid components (a and b, if you will) that are heated up and sent through two hoses and meet at a tip of a gun where the magic begins. This is a thin film that expands to 100 times its volume in eight seconds, when it's permanently set up.
How Much Is Attic Spray Foam
Spray polyurethane foam, or SPF, is the main type of 2-part, closed-cell spray foam used by insulation contractors. Large-scale insulation jobs require special equipment as well as safety gear to protect the installer from chemical fumes during installation. When the foam cures and hardens just several minutes after application, it's completely safe for as long as it stays in place.
There are several types of reflective roof coatings that impart varied reflectance rates/ values. Typically, the reflective coatings are what are commonly referred to as white coatings and there are also aluminum coatings typically used with asphalt. Highly reflective white roof coatings are typically comprised of acrylics, urethanes, silicones, SBS, SEBS, and other types.
During colder months, 2 component foam is very sensitive to temperature variances. Per product instructions, both tank temperatures need to be above 70°F (21°C) for at least 24 hours prior to use. All application surfaces should be clean/dry and above 60°F (16°C) prior to application. Variance outside of the recommended temperature can affect foam yield and performance. https://www.youtube.com/watch?v=ggLAUsiuI_o&app=mobile
For maximum durability and leak resistance, we recommend that two coats of topcoat be applied at 100 sq. ft. per gallon, or a minimum of 20 mils dry coating. If two complete topcoats are not applied, always apply two thick coats to problem areas such as scuppers, drain areas, ponding areas, seams, and repaired areas. Avoid using Elastek Solar Magic™ or The Shield™ on ponding roofs. Clean skin and tools promptly with water.
As mentioned above, These coatings can work with almost any roof type. Another advantage is they are long-lasting. The coatings are resistant to fungi and mildew among other common materials that damage roofs with time. Another advantage of the coatings is that they are seamless, providing a neat uniform coating. Elastomeric coatings offer individual benefits to certain roof types. For instance, polyurethane foam roofing benefits greatly from the coatings by getting great ozone and UV light protection. The heat reflexive properties also offer great benefits such as lowering cooling costs. This advantage is enjoyed regardless of the rooftype. The heat reflexive properties also offer anti-aging properties when coatings reflect harsh sun rays which age roofs with time. Elastomeric roof coatings are also simple to use, VOC compliant and nontoxic.
You've got no argument from me there, Dennis. Getting a good installer if you're going with spray foam is crucial. Many builders or homeowners don't know how to find one, however, and that's where third party inspections come in. Also, even good installers have bad days, but if someone comes in behind them with a measuring probe and a Blower Door, there will be fewer sub-par foam jobs.