Spray Inplace Foam Insulation??

[DirtPoor]

I have several out buildings with metal roofs that drip with condensation each winter/rainy season, here in the Pac. NW. Increasing ventilation doesn't seem to completely eleminate the problem. Even my carport, which is open on both ends, drips condensation onto my truck.

I know I could remove the metal roofing, on all of these buildings and add a vapor barrior of 2" insulation but that invite many problems with introduced roofing leaks.

I have been researching the possibility of DIY Spray Inplace Foam Insulation. Intially it appeared that this method was only available from a francised contractor/installer. I'm a DIY and want to do it myself.

I finally found an outfit that sells this system in kit form in various sizes http://www.rhhfoamsystems.com/ . The kit includes Part A, Part B, pressure tank and applicator hose/gun/nozzles.


The largest kit size produces 1000 bdft, that would be about 250 sqft of 4 inch foam between rafter giving an R-5 per inch. That may seem like over kill for a vapor barrier but it seems is would be difficult to get a thinner coverage.

Has anyone tried this type of system and especially as a DIY project??

Steve

[AndyF]

You may want to get a quote on having someone do it for you. I looked at some of the DIY kits and the cost was comparable to having it done.

[John350]

I have a plywood roof and had a pro come in and spray foam directly to the underside of the roof. The is very dense and by bonding to the wood it's almost like epoxy glue. Air can't penetrate between the foam and the wood so i'm assuming there won't be any moisture problems. I also had the side walls done directly to the metal. Besides keeping it quieter in the barn the warmth it retains made it worth the extra money over fiberglass insulation. For a 30X20 (10' high) area I paid $850 including the roof. I have a 100 gal propane tank and 65,000 btu furnace which I leave set at 40* when I'm not in the barn. I am in the barn frequently and a lot on weekends, I went thru about 175 gal of propane last winter. Like I said, i leave the furnace on 24 hrs a day from about Dec until about April when the night temps start getting around 30* again. I calculated that it cost me about $300 to foam it versus insulation but it was well worth it to me. You don't want to do it yourself. It is a very messy job, it's not worth the aggravation.

[John350]

Correction in my post. It cost about $300 more to foam it over the cost of fiberglass insulation. I don't know the ramifications of spraying it on the underside of a metal roof but it shouldn't be any different than spraying my metal walls. The only thing the foamer waited for was a good day when there was no condensation on the interior walls when he sprayed.

[Bird]

John, there are many different kinds of spray on insulation, so I don't know just what kind of foam you have, but I've seen a lot of it and it's great for awhile, but all that I've seen sprayed onto metal eventually started to peel, get condensation between it and metal, start rusting, etc. Of course, you may have something entirely different and most of the ones I've seen have been pretty old.

[John350]

Bird, I'm hopping that the product this guy used lasts a while. I don't know of all the technology that is gone on in the foam industry but I know the stuff this guy used was for commercial applications. The way it was explained to me was that once it bonds to a surface, air can't get between the foam and surface it is sprayed on. Hopefully this stuff will last a lifetime but I guess I really don't know. We have a manufacturer in town that makes this foam product and I had contracted with one of the guy's at the plant to spray this stuff. They have been in business for almost 40 years so I assume they have reliable products. My house, which was built in 1976, also had this foam sprayed in the walls when it was built. Although it is sprayed directly on the siding (wood), there is no indication that the material is degenerating. And I forget what the harmful chemical was that they used in the late 70's/early 80's in some foam products but this stuff does not contain any of it. Anyhow, you gave me something else to think about (worry).

[Chillimau]

I don't know what was available years ago, but recently read an article about the spray foams. If I remember correctly some are an open cell foam and some are a closed cell foam. The closed cell foam was a vapor barrier, had better R-value and was more expensive. The open cell was not a vapor barrier but a vapor retarder thus slowly allowed water vapor through.

[Bird]

We'll hope what John got is going to last well. I'll admit I don't know much about the spray on insulation personally, but I briefly considered it since my shop building was wood frame, metal skin and roof, and several people told me I'd be sorry; that condensation would eventually build between the metal and the insulation, the metal would rust, and the insulation would come loose and bits of it would be falling into everything in the shop. Maybe all their experience was with some of the older stuff.

[Pat]

I have the spray-on fibrous material not foam and wish I had the foam. My insulation is continually falling off in various size chunks.

About spraying directly on the underside of plywood. That waterproofs the bottom side. Any leak from above however small will admit water into the wood and there will be no evaporation/drying on the bottom surface. That could promote rot IF there is any leak on top. The San Diego tuna fleet went through a "phase" where a lot of the old wooden boat owners had their pilot house overheads sprayed with urethane foam to waterproof and protect and reduce maint on the old boats. What they got right away was UGLY and later a lot of wood rot.

I have seen a lot of foam jobs on metal roofs and so far NONE have had a problem. Of course these were all done within the last 15 years or so and therefore may be using newer technology than that which generated the bad press. I'd quiz the manufacturer of the materials regarding surface prep they recommend.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[billycalexander]

I've had a quote of 2 dollars per square foot here in Louisiana for only 1 inch thick coverage. How much was yours per square foot and how thick was it