how would a diy know if it is done right? Do they own a blower door? Duct blaster? Thermal Camera? Do they have a copy of REMrate available to calculate savings? Do they spend every work day fixing air leaks in homes and knowing where to find them and the best way to seal them? I don't think this thread has anything to do with illegal immigration, but yes, the foam industry like much of the construction industry is full of it. Anybody that talks about r-value not being important is a foam salesman. They don't test air tightness of homes and find out for themselves, they are told lies at their foamers conferences. I test homes almost daily and find that many homes are right where they need to be, and the ones that aren't are easily sealeable. You do realize that drywall is the air barrier? You can seal any penetration in drywall with a few cans of foam, to add an entire layer of foam is retarded and would be air barrier number two, the one that isn't needed. Walls in a house are required to have an air barrier on both sides, if there is air leaking into the fiberglass insulation cavities, THAT IS THE PROBLEM, not the insulation itself. If built right and tight (.35ach) fiberglass, like all insulations will provide the EXACT R-VALUE IT IS RATED AT. You talk like vapor barriers are a good thing....maybe you should do some research....NOBODY recommends vapor barriers for 90% or more of the climates in the USA. Lumber must have vapor transmission, or it will rot. The only places vapor barriers are even allowed are in the extremely cold dry north where moisture vapor is like gold and they have to run humidifiers to keep their skin from cracking. If you want to talk real world, we build over 25 houses a year and can give you REAL utility bills. We can show you the bills from the houses our friends in the building community used foam in. There is no difference other than foam was far more expensive. BTU useage is the REAL WORLD, not some website that told you something based on old leaky houses. You have to exchange the air in your house once every three hours, you cannot build any tighter than that, that is a CODE/STANDARD. Most of the homes we build w/out foam test too tight and have to have more fresh air input or they will be unhealthy for the occupant. I have been in and out of side by side houses, one foam, one fiberglass, with a thermal camera.....THE EXACT REAL WORLD DIFFERENCE IN INSULATIONS......there was no difference in wall or ceiling temperature with both houses set at 72 in the middle of summer, similar colors, and identical roof material. Neither foam or fiberglass are radiant barriers, and radiant heat from the sun can create more of a btu load than conductive heat. Most of the foam here is installed on the roof deck voiding all OSB warranties, and adding your attic to your conditioned load actually creating the need for a larger HVAC unit if calculated properly using ASHRAE standards. The bottom line is, if your house has exactly .35ach, r-value performance will be consistant across all types of insulation. Insulation is not there to seal your home, simply for conductive heat trasnfer=resistance value=r-value. That is it, if you don't know how to seal a home w/out spray foaming the whole thing, you must be blind or dumb. And if you seal your home, the only way to make sure you are still getting enough fresh air is by having it tested.......by a professional. Don't let companies selling diy products convince you that you can do it, ofcourse you can, you could build your own car if you want, but could you do it as well as Honda..........I highly doubt it. Spray foam is a con, I don't think REMrate has anything to gain from any particular insulation manufacturer. Download a free trial of REMdesign if you are not a licensed energy auditor, plug in the numbers for foam, and the numbers for fiberglass, you will find one of the most accurate answers out there for this debate, $/r-value is far more important than type of insulation if you are looking for a return on your investment you won't find it with foam using any roi calculator made. Just try it, it is free and non-biased. Like the foam salesman roark, I could have bought a foam spray rig instead of a loose-fill rig, but like many that did, it would have ended up for sale on craigslist because is does not make sense and I could never take pride in selling something that costs 400$/year extra on a mortgage, and saves little to nothing vs. competing insulations with similar r-values.