Is spray in insulation really better than bat insulation?

Derek A
by Derek A
  10 answers
  • Absolutely! Open celled foam is marginally better, but closed cell foams are 2-3 times as good. Not only do they provide far better R-value against radiant heat loss, but they totally stop infiltration and convective heat loss. Added benefit is that they make a home quieter and provide a vapor barrier to help manage indoor humidity.
  • 3po3 3po3 on Nov 03, 2011
    Agree with Nichter. Also, spray insulation can get into gaps and holes better than batts.
  • Dollar per dollar, spray foam properly applied will give you a pay back in savings on an average home in about six years over the cost of fiberglass. It makes the house air tight, makes it more energy efficient, It makes the house stronger and controls moisture when using the closed cell system. Although about twice the cost or in some cases three times the cost of fiberglass it is simply a better system overall. But if your on a budget, there are methods of using fiberglass and air sealing foam to achieve some of the benefits of both, Air sealing and lower install cost. A system that we use is called Ecoseal elastomeric sealant, this product is sprayed on and forms a tight seal on all wall joints and gaps. Check out http://ecoseal.knaufinsulation.us/kiss.html Its a sealant we use on all gaps and openings in a home, then we batt insulate or after walls are up blow insulation into cavities.
  • Dwyer Industries, Inc. Dwyer Industries, Inc. on Nov 04, 2011
    I agree with Woodbridge Environmental. Payback is about 6 years. In new construction payback is much less because you can design total system from scratch thereby reducing A/C size. Not every existing home is a candidate for spray foam. You need to have access to everywhere! Also, be careful that our AC unit is variable speed. Your existing unit will be too large in an existing home and a varaiable spped unit will help with that.
  • Ace Solves It All Ace Solves It All on Nov 10, 2011
    i agree with Dwyer Industries he is correct and it works very well when installed properly
  • HANDY HUSBAND, The HANDY HUSBAND, The on Nov 12, 2011
    Correct me if I'm wrong. Closed-cell insulation would be for the walls, but Open-cell spray for the roof rafters. The reason being if a roof leak was present it would make itself known to the homeowner.
  • No Ideally closed cell should be used for the roof at least for the first few inches. If a leak occurs on the roof, you do not want the open cell foam to absorb it. Closed cell insulation acts as a vapor barrier better then the open cell stuff. You can get away with the open cell as well, but the R value of the closed cell is a bit higher per inch then the open cell type. Regardless of open or closed if a leak occurs on a roof it will not show up near the spot where it is leaking anyway. The roof should be in good shape and properly maintained. What my guy uses is about two inches of closed cell then on the 2nd pass uses open cell as its about $1 per foot less to install. As far as walls, floors and roofs. Open cell expands and and flexes better as the framing moves with wind and settlement. This is the preferred material for residential construction.
  • HANDY HUSBAND, The HANDY HUSBAND, The on Nov 13, 2011
    Very good Woodbridge. I am glad I asked the question for your follow-up answer. Thank You. Lou
  • I hear of numerous instances of open celled foam holding water and causing mold and rot.
  • Dwyer Industries, Inc. Dwyer Industries, Inc. on Nov 14, 2011
    I thnk closed cell is a better product for the Northern States, but in hot humid climates especially in hurricane zones I prefer the open cell product. Their are many open questions concerning long term effects of using closed cell when leaks occur. My experience through the hurricanes has been that the open cell foam (which is waterblown) gets wet and over a week to ten days after the damage completely dries out. I had several customers that had trees fall on their homes and exposed the open cell foam and there was no long term problems. Also, while most closed cell foam are R6.5-7.0 per inch and open cells are 3.5-4.0 per inch, R Value is just a matter of spraying the open cell thicker. Either way, I thnk for new costruction, spray foam is the best alternative. In response to Nichters concern about holding water and causing mold and rot, most of the oepn cell foams are hydophobic. I have experienced the soy based foams not drying out and turning into a type of pea soup consistency when it gets wet, but that was about 5 years ago. There are some applications that open cell should not be used in, namely in crawl space conditions where there could be mositure migration from the ground.