so even though the walls & ceilings are not sheetrocked the attic is decked? interesting. normally, when insulating attic floor with foam the foam is sprayed against back side of the sheetrock ceilings. since your attic floor is decked, spraying against the decking from inside the hosue would be how you'd do it. so to do that..first the perimeter of the ceiling would be sealed. you want to seal the top plates, wire, pipe penetrations. then fill the ceiling joist bay with foam. to get the full depth of the joist you'd over fill the joist bay, then trim off excess prior to installing sheetrock ceiling. this would be option three. and the one I'd chose recommend. everyone...house is North Carolina. ducts in crawlspace, so equipment is either in closet inside living space, or in crawlspace. if the roof is high, and not used for ducts then it is more cost effective to seal & insulate attic floor. OP, check into what foam is used in your area. we use open cell in hot humid climates. are you sure the ceiling joists are 2x10? if so, that gives you 9.5" for insulation with open cell..that would be about R-36 depending upon R-value per inch of product. shop foam insulators wisely. you want a full joist bay fill, not an 'average' fill. what they mean by 'average' is that if you add up low spots & high spots of foam it 'averages' out to xxx. you want full depth everywhere. excess is cut off so that sheetrock install is smooth. ask to see jobs of the foam companies in progress. ask to talk to former customers. once completed..blower door test the install to make sure it has stopped air movement between attic space above into living space below. I gotta ask....why floor the attic so early in process? and where are heating system & water heaters? tell us locations, what size & what fuel type please. how will attic above foamed floor of attic be vented? do you have recessed lights? what provision has been made for recessed lights & insulation plan? are recessed lights Insulation Contact Air Tight ICAT?? knowing the answers to these questions may change answers to previous questions. best of luck

I built my own using a 4 X 8 sheet of 1 inch foam insulation. I found a set of plans to do this. Here is a link which has a similar plan. You can use even thicker foam insulation if you want a higher R-value. http://www.jacksonemc.com/Do-it-Yourself-Energy-Projects.43.0.html You may have to modify it a bit to fit your stairs. It was not very difficult to build. I put down weather stripping on the wooden frame. The box sits on the weather stripping which makes a tight seal. I even used the left over pieces on the sides in order to give it extra strength and weight. When I go into the attic I simply push the box so that it stands up on one of the long sides. To close I just lower the box into position onto the weather stripping. For about $25 you can build a custom fit cover. I think the key is the tight fit to stop air infiltration. I am not sure how good a job the store bought versions will do.

don't you think it is because this rb paint is not hvac approved? HERs Raters rarely recommend radiant barriers as ducts and mechanicals condensate in our attics. If the ductwork is in a conditioned space...that is a different story. As we go to two stage units and R-8 ductwork in unconditioned attics, the condensation due to colder air being produced in these units that operate in mostly low speed produce so much condensation that they literally cause 'rain' in the attic. while it took me a long time to get on the open cell foam roofline install..it solves the problems. of course that total encapsulation of attic is a joke. there is always areas missed when foam is installed. few test with blower door to verify leakage. fewer actually go back and seal areas of leakage. if you do a rb install there is still air movement between attic and living space. a better investment is air sealing. 25% reduction seems to be an inflated % to me. I would think half of that would be more accurate. there is a reason that Energy Star removed rb from their recommendations. my rb works well because my air barrier between attic and living space is well sealed, and no ductwork or mechanicals in attic. foam companies also want to use foam to 'seal' ductwork (which you don't mention that your company does) foam does not seal duct leakage, nor is it approved by hvac industry. Mastics seal. not foam, duct tape or bubble gum. approved products work.

I need the input from some of you insulation gurus to know how to proceed with this house. Originally a ranch, it is now conisdered a cape, since part of the attic was bumped out to form two extra bedrooms and a bath. A door in the hallway leads to the unfinished part of the attic. There is ample room to stand up in most of it, and there is a crawl space over the bedroom wing. There are two air handlers (system is hydronic forced air), one in the standup part, and one in the crawl space. The old insulation, rock wool, is mostly exposed and dirty at this point, and dried out and flaking. I know we get some of the filaments coming down through high hat openings in the bathrooms, and I'm convinced, althoughthe HVAc company says "no", that a good bit of it is getting into the duct work, which explains a very dusty house, and problems breathing since we moved here three years ago. W had major ice dam issues for two years, owing to the heat in the attic,and a warm roof. We just had a second roofing job done (yes, we have done two), now bringing the ice shield down over the eaves onto the soffits, to prevent water backup from the gutters as the ice melted. This has also, I think, warmed up the attic even more. The HVAC company does not want to see the temps dropped up there, due to the equipment. I had two insulation guys here, one of whom wants to rip out everything accessible, including the insulation in the crawl space, which is stuffed between the beams . There is no actual floor in that section. I worry about the electrical and plumbing lines, and damage which might be done while they rip out and replace. They also want to insulate the ceiling, effectively making the attic part of the living space - which would aso, they say, keep the warm air from going up to the roof, and protect the equipment. Second insulation guy says it is imppossible to rip out the old insulation on the floor of the crawl space ( perhaps it is just too much work??) and wants to staple new insulation over it, but remove and replace what is accessible in the main part of the attic. He has said "no" to insulating the roof line, stating that in the summer it would be hotter than Hell!! Someone else told me it could cause the roof to rot (vapor barrier?). So now I have two different takes on this, but my major concern is getting rid of the loose stuff which is permeating the house, as much as possible, and possibly keeping the air a little cleaner. Another aspect of this might be keeping the warm air on the first floor from going up to the second floor, costing a lot more to heat the house. I just don't know which of these guys makes more sense, and whether one or the other has a valid argument. Can anyone help with this??? Thanks!