The underside of our roof is right at 600 sq ft, and most big sized spray foam kits are 600 sq ft. Though I've seen additional 120 board ft kits that I may get just to make sure I had enough (or even 2 600 ft kits). I called a local pro contractor, and a full order for him is 2000 board foot, and he needs pretty substantial short power. So If I hired him, I'd be at the mercy of his schedule in hopes he's have something left from a big job, and I'd need a bigger generator than our honda e2000.
So how messy are the kits? How much work are they? Is it easy enough to put down a thin 1" layer, or is hard to control? I'm less concerned about R factor than just prevent condensation. Thanks!
I'm going to DIY the spray foam on my metal roof. My research says they don't require electric power to use. From the youtube videos I've watched application seems pretty easy and thickness control pretty manageable.
I grew up in Mexia and it gets pretty moist and sticky over there. For that reason I think I would want at least two full inches of high density foam (roughly R-10), any less wouldn't provide enough insulation to prevent the underside of the foam from potentially going down to the dew point temp at night where condensation will occur. I expect Mills County is drier than Mexia, but not dry enough that 1" of foam would do well.
Good luck with whatever you choose...keep us informed along the way.
I'm very interested in this as well, and would appreciate any insights or discoveries you may make. Good luck!
??? I've only used the small cans of foam----thickness control is harder then it appears in the videos and removing excess is not easy at all.
My wife's cousin bought two cans of that stuff to do his camp. One was enough to do the floor, and he sold me the other one, and agreed to spray my floor with it today. At around 35 degrees, he discovered that it froze, and would not mix or spray properly. He'll try again on Sunday when it will be in the 50's. I'll have pics and an update after that. Stay tuned!
It is best to warm the container up. I would place it in front of a heater, just don't let it get to hot. When I use the small cans of foam up here (Alaska) in the winter I set them on a box in front of a heat until they are toasty warm. It really makes a huge difference in how much foam you can get out of them and how quickly it will expand.
Chuck
My research said it works best when the material in the cans is at 80 degrees or so. The website also said you could spray when surface temps are below 80, just set a heater up in front of the cans. If memory serves if the spray hose temps get too low, it won't work well. One of the advantages that the pro's have is that their spray hoses are heated.
It's all done! And the best part is that I didn't have to do it! It was about 60 degrees outside and sunny, which was warm enough to finish the job.
Is it messy? Well..............
(https://i223.photobucket.com/albums/dd127/MaineRhino/Mountain%20Camp/028-2.jpg)
(https://i223.photobucket.com/albums/dd127/MaineRhino/Mountain%20Camp/038.jpg)
It was applied and it expanded to 2" to 4". It's a 20'x26' area and it took one whole kit and part of another. The "HandiFoam" is closed cell and has an R-value of 6-7 per inch. Be sure to buy extra fan nozzles. It sets up in the nozzle in 30 seconds, so don't plan on taking many breaks.
(https://i223.photobucket.com/albums/dd127/MaineRhino/Mountain%20Camp/030-1.jpg)
(https://i223.photobucket.com/albums/dd127/MaineRhino/Mountain%20Camp/032-4.jpg)
We can feel the difference on the floors already! At about $650 per 2-can kit, it can get expensive, but it is air tight, bug and rodent-proof, water-proof and easy to drill through when we finish the plumbing. [yuk]
The abdominal foam man. ;D ;D
It's good to hear from a real life user.