Sheri: The Aluminet stretches in one direction only, so when you order it, make sure you have the fabric cut to stretch in the direction it will hang from top to bottom. When the sales rep from IGC (where I ordered mine) told me the vents would open under the fabric, I was a bit doubious, but she was right. The key is to mount the fabric without stretching it tightly. My husband was concerned that the corners of the vent windows might punch holes in the aluminet fabric and wrapped rags around them. So far, even with the vents opened full and pulling the fabric, no holes, but I'm looking for a more elegant solution. Fat, self adheseive foam bumpers come to mind. But I didn't suggest that you use the aluminet AS a screen, only that when it's draped over the ROOF vents, it serves as one, which I found ironic, because we made screens for the roof vents, that will soon serve as storm panels for winter, as we can use them to hold bubble wrap in place under the vents. For your intake vents, use standard screening material, in a frame. To screen the powered intake vents on my GH, we used white vinyl house trim materials to create a box frame, 5- 1/2" deep, to allow the vents to open out, then just made screens using the screen channels, corners & spline sold in any home center. The box is made of 1 x 6 vinyl trim board, (actually 3/4 X 5- 1/2) so the edge facing out is wide enough to accomodate the screen frame, that is mounted to the box face with screws. To give a surface to mount the box to the GH, we used vinyl brickmould. The box sits inside brickmould, attached with small screws. The brickmould was fitted tightly around and to the fan frame, sealed with silicone. Once we fiddled the design, they were pretty easy to make and give me the ability to both remove the screens for cleaning, and in late fall, when we seal up the GH for winter, we can seal the vents by placing insulation in the boxes, then use the screens to hold it in place. My inspiration was shadowboxes, which, when you look at them, are no more than a picture frame with a second frame inside of it that projects out, with another frame on it's face, to hold the glass. From the craft shop to the GH. LOL!

Oh no, I didn't realize how sulfur might affect my cats and dog. I thought it was nontoxic to mammals! I did more research, and saw this in the Merck Veterinary Manual: Sulfur and lime-sulfur are 2 of the oldest insecticides. Elemental sulfur is practically devoid of toxicity, although poisoning has occurred occasionally when large amounts were mixed in cattle feed. Specific toxic dosages are not known but probably exceed 4 g/kg. Lime-sulfur, which is a complex of sulfides, may cause irritation, discomfort, or blistering but rarely causes death. Treatment consists of removing residual material and applying bland protective ointments plus any supportive measures that may be indicated. What fungicide would be safer for my animals? Sulfur? Or tebuconazole (Bayer Advanced Disease Control)? Does tebuconazole also leave a heavy film that can rub off on the animals' fur and get ingested during grooming?

water- congrats on building an efficient home. its good to see results and suggestions taken by the pros that offer it up on this forum. Jen Tight homes need to have correctly sized hvac for it. There are very few mechanical guys that know how to size units for tight homes with very low air leakage. Most "rule of thumb" sizing does not work. The large units short cycle and do not run long enough to extract the humidity out of the air like you mentioned. Smaller units will have longer run times, correct, but they will run at a much lower speed so the energy usage is lower and the house maintains better. My home is an ICF home with similar r value (r 28 average and r60 attic with some r50 foamed rafters) and air tightness with triple pane windows only uses a 2 ton AC unit. The square footage is about 3800 total conditioned space. In zone 6 with 7200 HDD, the furnace is a Lennox modulating that ranges from 22k btu to 70k. It runs around the 25k for most of the time in the winter at 0 and below. Rarely does it ramp up to full speed ever. The mechanical was carefully designed and selected, and there is also an HRV installed. The full mechanical, high end equipment and HRV only cost $12k for the home nearly 4k sqft. I have seen people post numbers on here that are over double that in dollars and sizing for the same square footage. This is due to some or all of: code min. home design and construction and/or oversized hvac. Now, its great the spray foam is performing, but without starting the debate, I just want to be clear to any readers that they are other methods of achieving a tight home, high r, and the same results as the poster WITHOUT using spray foam, all at a reduced cost of spray foam. And as always, put the money into the shell of the home, not the hvac! Increase the shell, decrease the hvac. Most cases, dollars are a wash or less and energy usage is lower for the life of the home!

I'm not getting into the vented vs sealed crawlspace pro & cons. but to answer OP's question, 3.5 to 4' is sufficient working room for spray foam install. closed cell has a stronger smell than open cell IMO. but the smell fades after a couple of days with either. if you are anyone in the family are sensitive then install should be done when ample time is allowed for any smells to dissipate. I'd start by investigating the recommended install (joists covered or exposed). I'd think that 4" would be ample at R-28, but I don't know your requirements in your area. just remember that you have to meet the code minimums. R-value of foam into inches of foam. not "performs like R-xx" or "average fill" same depth or MORE...not less everywhere. No Q or K values, R-values only. it is the installer that is the key figure in the install, not the salesman. make sure you are on page with the installer & be willing to go into the crawlspace & measure low spots before they leave for the day. it is worth your time. and yes dehumidifier in vented crawl is trying to dehumidify a portion of the great outdoors. best of luck.