Some answers to the most common questions.
Q.  Is all spray foam the same?
A.  All spray foam is intended to end up as polyurethane foam insulation, but not all foams are created equal. Dimensional stability and adhesion are top priorities when I consider applying a product. Other factors that come into play is the product safety, for both the homeowner after the application and for myself during the application. I'm currently spraying Huntsman HeatLok HFO High Lift and it has been a breakthrough in innovation of foam technology for end user safety as well as 1000x better for the environment than previous foam formulations. Re-occupancy is 1 hour for workers and 2 for residents where as previous foams this was 24 hours. Huntsman is a coalition of companies that been around since 1977 including Lapolla, Icynene and Demilec. All their products have been fully certified and have the documentation to back it up. 
Q.  What color is the foam? And can you dye it?
A.  The foam is light yellow to white in color when new. As it is exposed to light over time the surface will yellow. You could dye it, but it will never stay the color that you do. Its best to paint or coat the foam if a certain color is desired.
Q.  Does spray foam make my house too tight?
A.  For energy efficiency you can't get it too tight. In a home you will need a Heat Recovery Ventilator to mechanically ventilate your home. HRV's operate by preconditioning and filtering the incoming air. Mechanical ventilation recovers 80-92% of energy that would normally be lost, where natural ventilation loses 100% of all conditioned air. Plus HRV's really aren't that expensive. Your HVAC system can be sized about 50% smaller making it a wash in cost when adding the HRV normally.
Q.  Should I put wrap on my pole building? My builder thinks it's a good idea so I can replace a panel if it ever gets damaged.
A.  NO. Your builder doesn't know much about the chemistry of spray polyurethane foam. Spray foam does not adhere to building wrap, which makes for a high chance of failure. You need adhesion to a solid substrate. At the end of the day the builder has no liability to an insulation system that fails, so it's best not to take his advise if he's telling you to wrap the building. Also if you do damage a panel you can get the panel off the foam, it's not to difficult. Or you can even put a new panel over the damaged one if you wanted. Spraying directly to the steel adds an incredible amount of strength to the steel panel and the building.
Q.  Will spraying foam directly to the steel discolor the steel?
A.  No. I'm not sure where this idea came from, but absolutely not. 
Q.  But if you spray foam to the under side of the roof deck, I'm heating extra space right?
A.  This is a tough one to understand. You are creating a larger thermal capacity. You are not wasting any energy, because you have to lose that energy to be wasted. Spray foam to the under side of the roof deck is extremely efficient and very little energy passes through the foam. Much less than what would pass through cellulose on top of the ceiling. And for a house with a lot of energy leaking recessed lights, they are no longer energy wasters. 
Q.  But if you seal up my attic, where will the moisture go?
A.  What moisture? Condensation only forms when moist warm air meets a cold surface. With spray foam insulation this is completely eliminated. Your attic becomes a controlled climate, there will be no more moisture in your attic than moisture in the rest of your home. If you have 40-50% humidity in your home, you are going to have 40-50% humidity in your attic. This is because moisture, like air pressure, always moves from high to low until it has equalized. Since the laws of physics don't allow us to create something from nothing, there is no way to have anymore humidity in the attic than the living space of the home with the use of closed cell spray foam on the roof deck.