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Posted: Oct 17, 2010 10:13 PM
Spraying under overhangs
Doing a job right now with an overhang 11" off of the roof deck that extends inward to the side wall 5 ft and about 30' long. So I have 11" of clearance that I have to spray a flat surface to 5ft inward X 30' long.

Plan on using multiple 4' x 8' slip sheets and tying them in with foam, once I screw down my I-190 Fastening Pattern.

Any suggestion out there other than slip sheets. I am pretty sure that my fusion is 8" by itself, the foam thickness if 3", so spraying anything other than a 10-45 degree angle will be out of the question when trying to fill in the gaps between my slip sheets when I tie them all together.

How do some of you pro's handle?
Daniel X
Posted: Oct 19, 2010 03:17 AM
So you've got an 11" tall opening to spray 5' in?

Having a hard time understanding what the slip sheets are?
Posted: Oct 19, 2010 07:03 AM
Correct! In this case, a slip sheet is a 4' X 8' sheet of 5/8" Densdeck primed. I will spray 3" of spray foam to the 4 x 8 sheet of densdeck primed, leaving about 6" around the entire perimeter to fasten down to the deck as well as in the middle of the sheet to fasten to the deck.

Once the slip sheet is foamed, I will slide under the 5 ft overhang that only has 11" to work with, then fasten the slip sheet down. I will do this across the 30 ft span. Once this is done, I will slide my big az into the 11" gap with an 01 chamber and fill in the cracks and vertical wall as best as I can with roofing foam, then get in there with either a saw or 6" grinder to smooth out.

I guess that I was looking for someone to say, "you are doing the hard way, this is how we do it!"
Brian Currie
Posted: Oct 21, 2010 08:52 AM
I'm not sure if I understand exactly what you're doing but if the deck is not down yet I have stapled cardboard or typar down in the cavities before and sprayed from top little air space at top not a factor
Posted: Oct 21, 2010 09:38 PM
I sprayed this morning. It was a metal decking that we installed densdeck primed on top off.

The overhang was 11" from the deck and extended in 5 ft. So basically, the roof had to be sprayed flat with only 11 inches of clearance from the roof to the deck above.

We were not allowed to simply fill the void with foam, it had to look just like the other 18,000 sq. ft of 3" foam roof.

Came out nice. I need to lose some weight though. I don't even think my head is 11 inches, so it was tough to squeeze under and try to spray with just a few inches.

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