I am building a house in Central Texas (Caldwell). Several builders are cautious about using foam insulation and/or a closed attic. I would like to use both. Here in Texas, heat and humidity (except for the past few years of drought) are a continuing problem. Which type of foam would be the best to use in our home, where should the vapor barrier be or should be use one at all, if we are using fans in the exterior walls to supply fresh air to the house, do we need a vented attic or will it cause more problems than it solve? I have printed out your article and the blogs to give to my contractors and architect, but I would really appreciate your comments on the products being used in my part of the US. 
I started using Gaco years ago primarily to solve ponding water Problem. It has work well, solved my problems with other roofing options and repairs as well as many other Flat roof issues.  My only problems were experienced when I did not clean the surface well enough for good adhesion.  Follow the Instructions.  Great product and highly recommended. .
I've seen this only once, and it was with closed cell foam, but I've heard of it happening with open cell foam, too. I don't know the details, but I've heard it could result from a bad batch of chemicals, improper mixing, or too high a temperature. Whatever the cause, it's not a good thing. The photo below shows how the spray foam pulled away from the studs. A little bit of uninsulated area like that adds up to a lot of heat loss/gain when the whole house has that problem, as it did here.
In the early days of insulating attics, people believed the insulation was a heat source. That’s not the case, as the insulation is actually a barrier between two areas of different temperatures. As for the “hot roof” theory, the unvented attic system could make the temperature of the roof go up a little, but this increase won’t cause damage to your shingles.
Product innovation over the years has seen the introduction of several different types of spray foam insulation. Primarily in residential and commercial construction, open-cell and closed-cell spray foam is used while high-density spray insulation is used as roofing foam in commercial or industrial construction. Open-cell sprayed-in foam insulation, a soft low-density material, is typically used for interior applications such as wall cavities, underside of roof decks, attics, basement walls and crawlspaces. The open cell structure of low density foamed insulation allows for moisture permeability to help contribute to moisture management and bi-directional drying of the wall assembly. 

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).
Note: The practice of foam insulating the attic has raised eyebrows in the building industry because "standard" roofing techniques call for the attic to be ventilated; however, in a vented attic situation it will become approximately 130 degrees in the summer. There's no reason for an air-conditioning and vent-ductwork to have to work in that type of severe conditions. By applying Icynene right on the underside of the roof deck, the severe temperatures no longer exist in the attic. In short, the attic is now a "conditioned" space of the house that is just as comfortable as any other room in the home. This is called a "Compact Roof", which means you can frame right up against it. The one drawback of using expanded foam on the inside of the roof is that this will cause the temperature of the shingles to rise, but how much is not yet known. And how much damage a rise in temperatures could cause is debatable.
Starting a new build (1 1/2 basement walkout), all 2x6 exterior walls w/ brick veneer in CZ3. Above grade, would like to do spray foam in 2x6 walls, 1/2" or 1" of rigid foam board on the exterior, and a 1" air gap. Will this require a house wrap or can I do w/o the rigid foam and go with a housewrap? Also, any recommendations about insulation strategies for the finished basement. Thanks!
I started using Gaco years ago primarily to solve ponding water Problem. It has work well, solved my problems with other roofing options and repairs as well as many other Flat roof issues.  My only problems were experienced when I did not clean the surface well enough for good adhesion.  Follow the Instructions.  Great product and highly recommended. .
I have to insulate my walls at the end of this week. That does not give me time to procure slow-rise foam, so my stud cavities will be filled with foam before I'm ready to fill the corner voids. I will not be able to drill straight through the corner studs. Instead, I will have to remove material where the studs meet. What sort of tool do you envisioning me holding while I create space to pump foam into my 1972 corner voids?

Wallis knows proper application of urethane products is paramount in have an effective insulation barrier. Insulation performance is also based on the R Value provided. Our minimum application is always more than adequate to give a proper R value. Wallis will never skimp on applying product. We make sure you receive what we promise as a minimum. Wallis always does a proper application of material with out worry of insulation thickness or performance. We always make sure that you are receiving the Thermal Break from heat and cold that is expected and appropriate for your needs.

Light-density open-cell SPF is commonly known as half-pound foam. It is a semi-rigid material with a sponge-like appearance that expands during installation and creates small, open cells that are filled with carbon dioxide. Due to its ability to expand during the application process, it fills cracks, crevices and voids and adheres to irregular surfaces or substrates to form an air sealing insulation.[12]

Spray foam insulation is a great product. Homes insulated with it can be some of the most efficient and comfortable homes built. I've been in plenty of these homes and can tell you that when spray foam is installed properly, they outperform 99% of fiberglass batt-insulated, stick-built homes. (I can also tell you that 73% of all statistics are made up on the spot, so please don't ask for documentation of that statistic.) http://www.youtube.com/e/ggLAUsiuI_o?app=desktop
Spray Foam Insulation is simply the best insulation you can install in your home or building in Texas. It is estimated that up to 40% or more of your home's energy loss is due to air leakage through holes, cracks and gaps in the building structure. SPF can seal your home from air and moisture leakage, save on costly utility bills, strengthen your home, and help to protect your family's health from dangerous mold and airborne pollutants.
I have used the Froth-Pak 200 to air-seal rim joists--the area above the foundation wall in a basement. The first time I used it I did not shake the canisters well enough and the foam did not cure properly. Don't just shake the box for a few seconds. I take the tanks out of the box so I can shake/invert each tank for a minute or two. You will be able to hear the chemical sloshing around in the tanks. Also, don't ignore the recommended temperature for application--around 75 degrees F.

Where Can I Buy Spray Foam Insulation

×