After researching this, Im curious about a method called poor mans sprayfoam where foamboard is cut to size between studs and sprayfoamed around the perimeter. Aside from the labour doing the job yourself, the cost seems comparable, is one better than the other? What about the quality of the canned sprayfoam around the perimeter? When i see sprayfoam done, it is never a full depth of the studs, so you would get 2.5-3 inches in a 3.5" (2x4) wall. Any thoughts?
According to the Department of Energy, an estimated 20 to 40 percent of a home’s utility bill could be going to waste from drafts and air leaks around openings. As temperatures cool and energy costs rise, the positive impact of energy efficiency on a building comes into focus. Air can enter and escape a structure through every gap, compromising the building envelope. Adding the right insulation and air-sealing will close these gaps, keeping interior spaces comfortable and reducing energy bills.
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).
Spray Foam Attic Insulation
In the case you have above the installer wasn't reading his foam. They must be trained to do that as they spray. Temps and conditions are constantly changing thru out the day. Either he wasn't properly trained or if he was,he wasn't doing his job! This is a serious problem with people jumping in to the foam business. A lot of homeowners and builders are looking the best price and end up with someone who doesn't know what they are doing. Hope this info helps. Foam insulation is a great product. It just has to be done right by someone who knows what they are doing.
How Much Does Spray Foam Weigh
I don't know if it's common or uncommon, but installing a layer of rigid foam above your roof sheathing in order to interrupt thermal bridging is always a good idea, and is preferable in all respects to a roof assembly without any rigid foam above the sheathing. If you decide to install rigid foam above the roof sheathing, you shouldn't use closed-cell spray foam under the sheathing; either use open-cell spray foam (which is vapor-permeable) or a fluffy insulation like cellulose, mineral wool, or fiberglass (any of which will allow the roof sheathing to dry to the interior).
How Much Is Spray Foam Insulation
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.