The board you put on the wall should not be be foil faced. Shiplapped board is best. If not, tape all joints with builder's tape from Tuck or Tyvek, for instance, or with fiberglass mesh and mastic. As a DIY project, the most cost effective would usually be one inch of XPS on the wall followed by conventional framing (on top of a strip of XPS) with the space between filled with fg. An alternative would be Wallmate or equivalent. Here's how it's installed. (Scroll down to interior.) But this may pose challenges in wiring. Building Science does give the nod, too, to EPS. But it has to be thicker, as the R Value is lower. And you will have to be careful about summer humidity levels. (The same applies to XPS, I find.) Smart vapour retarders, the only one of which I know is Membrain, are another possibility. They permit the use of fibrous insulation. But unless your conditions match those of the only test I've seen, I would be hesitant to use it unless my soil conditions and climate were similar to the test subject. If you use XPS on the floor, you are insulating it. It will be more comfortable. But I notice that not even the US Department of Energy has any recommendations on R values for basement floors. In an extremely cold climate, I can see floor insulation as cost effective. Is Sarah Palin your governor? ________________ Note: Whenever you are air-sealing and insulating a home you should pay attention to any fuel burning appliances that depend for their supply air on air leakage. It's advisable to buy and install CO detection devices. And you may also have to provide direct air supply venting to furnaces, water heaters, fireplaces etc. Spend $49.95 and save your life. Here is a link that might be useful: Department of Energy Recommended R Values

the basement is already finished That could change the story. If you haven't already done so, ASAP use lots of heat and dehumidification--even rent industrial dehumidifiers--to draw out the moisture. Mould does love drywall, wood and hidden areas. When that's done, you might want to test suspicious sections for dangerous mould. (See link.) A couple of builds ago, a neighbour's wall started leaking. My fault, he figured, as I had removed a row of his hedge that was on my property. So he "designed" a system of weeping tiles to pick up surface moisture. The installer (my grader) agreed with me it wouldn't work. But, heck, money is money! A couple of months later, in bitter winter, a crew excavated eight feet down by hand along the foundation, found the settlement crack and patched it. No more water. Maybe your system will work better. Here is a link that might be useful: Inspectapedia on mould

Sounds absolutely fine to me! 1)-3) No comment 4) The insulation will make little difference as far as sound proofing. If keeping the noise down is a big priority, use a damping system such as Quiet Rock, Green Glue or resilient channel and an extra layer of drywall. 5) If the heat pump doesn't keep humidity below 35% RH, you can always put in a portable dehumidifier. 6) If the inspector is uninformed and therefore insists on a polyvinyl vapour barrier, it won't hurt the system. There's no need to bother with Membrain, which is designed to be effective with fibrous insulation. On one project I did with cc on the walls, the inspector approved it without poly. On walls with XPS, inspectors have insisted on the poly.

no. put the 1st layer xps between furring strips already there. then put another 2nd layer that will cover both the layer of xps against the block & furring strips. when installing drywall use longer screws and screw thru drywall, top layer of xps & into furring strips. then you'll have the layer against the wall installed inbetween strips, and another layer of 3/4" xps on top. this will give you as much as in basement. not suprised you didn't find R-value. tj..for my radiant barrier in the attic..where the work in hot climates, I paid .05 per sq ft. single sided fsk radiant barrier. this is my material of choice. not much sense in paying more for a more expensive product that works just the same as single sided product. what sells the more expensive product is hype. I'm very pleased with radiant barrier in attic in my hot climate. reflects the heat nicely the actual insulation on the floor of the attic is what keeps attic temps in the attic. not the radiant barrier. the radiant barrier has minimal R-value. its value is in emissivity. even with 4'x8' sheets of iso board ( R-7 foam with foil facing) I can cut with no waste. tape measure, tsquare razor knife. no problem. oh and I get actual R-VALUE. Double-bubble stacked x3 with 1/2" air gap = r50. This is FACT. no its sales hype. if you find R-value of foil bubble foil wrap..please post it. just not from mfg selling the product, a site where the info is unbiased. I'm not the only person to know this is true. those scam artists come out every year taking advantage of older people with RB rolled over insulation in attics. scam. scam. scam. http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/29497/The-Foil-Faced-Bubble-Wrap-Sham-Understanding-Radiant-Barriers read the comments Kvalue folks strike again! LOL!