I used 2" and cut the pieces out of a 4x8 sheet and cut them 1/4" or so shy of the average bay sizes to give room for the foam to go in. I had a few that didn't want to stay against the rim joist as they were foamed and I didn't have any washer nails to hold them in tight. The few that gave me trouble got marked with a marker and I drilled a few holes in the foam board and shot foam in the back side and let it sneak back out the holes and shaved the excess off. it is a night and day difference between the foam board and just having batting stuffed up in the spots. I don't have a heated basement and can tell a world of difference. I think I got around 30 plugs out of one 2" 4x8 sheet of foam board with a few pieces left over for odd sized spots. One can of great stuff foam did between 8-10 plugs with a price around 6 bucks a can and the sheet price of $22.50. Once you get set up and going it doesn't take too awful long to do. I got the ones with obstructions fitted with a hand saw and in place first and then stuck 10-12 in a row so I just had to concentrate on foaming. I noticed that if you spend too much time putting the foam blocks in after the can has been partially used it wouldn't go near as far as if you started foaming and went from one to the next.

I understand what they are saying, but...I have done a lot of research on this and including on these forums rigid foam seems to be the way people are going with this. You can check out some great videos in you tube also. Can we know for sure our basements have no humidity or moisture issues? I know I have to run a dehumidifier in mine in the summer, but over all it is pretty dry. The other issue some folks have raised is even with the rigid foam you have to make sure it is pretty tight so that moisture does not build up behind it and cause rotting of the rim joists. So much to think about. That is why I may just go with the spray foam despite the cost. I have some pretty big holes where the vents are going through the floor. I can feel the cold on the floor in my living room and dinning room. If you google rim joist insulation you will find a lot of information and videos.

I build in what may be a similar climate. (Please note that gardening zones are not climate or hygrothermal zones. See International Energy Conservation Code (IECC) energy zone map below.) I only use high-density spray foam on the rims. But the way you describe your retrofit, the combination of Roxul with sealing may be more appropriate if you see a need for accessing any of the pipes that would be buried in the foam. (I can't imagine why you would need to access the wiring.) Unlike fiberglass, on which mould grows when wet, Roxul will not wick water and does not have to be replaced after heavy wetting. However, unless great effort is put into cutting the insulation to fit, there will be gaps that reduce the R value. Whatever method you use, you might want to meet IECC minimums. Beside referring to the table above, you can use the map on this link to find IECC county-by-county insulation requirements. If this is an unfinished basement, termite shelter tubes will be visible on the foundation walls inside; and, for the same reason, be sure the foundation is exposed on the exterior. There's no particular moisture problem. Sources of ignition will have to be shut off during application. Don't forget the water heater. This post was edited by worthy on Wed, Oct 22, 14 at 0:02

you are correct....open cell is the cheaper, less R and higher perm (allows more water through) then closed cell. Closed cell will be a added cost, but would probably be worth it in the basement at least. Closed cell, in general, will seal up your entire house better then open cell, as well as add structural rigidity to your 2x4 framing making your house stronger. Open cell does not. Closed cell is not water proof, as it seems your questions are hinting toward. Cellulose is just fine for the attic, and going with more closed cell is a waste of money IMO. An animal can rip apart open cell just as easy as getting into cellulose. Besides, if something gets in there you have bigger issues anyway! Also, your roof is suppose to be water proof....not your insulation. If your roof is failing, you do NOT want a water proof insulation anyway. This traps water and allows wood to rot, thus a possible structural failure in your roof without you really even knowing. You may also be money and r value ahead to practice air sealing your walls with caulk and then using a blown fiberglass or dense packed cellulose in your walls. A side note...spray foams are THE most expensive possible way to insulate a home, and most cases you will never see a ROI compared to dense packed cellulose and blown fiberglass with air sealing especially in your climate. (note, I never mentioned batts).