We are turning our roof into an unvented roof assembly by raising the roof and blowing in SPF. We are planning to leave the existing vapor barrier down but remove the fiberglass batting and then adding 6" of SPF in all the cavities, to completely seal and insulate the house. Should we have any concerns about doing it "upside down" and not spraying the foam directly to the underside/sheathing of the roof?

In the early days of insulating attics, people believed the insulation was a heat source. That’s not the case, as the insulation is actually a barrier between two areas of different temperatures. As for the “hot roof” theory, the unvented attic system could make the temperature of the roof go up a little, but this increase won’t cause damage to your shingles.
The closed cell foam has a high density that is much more than the density of the open-cell foam. The compact and smaller cellular structure of the foam can barricade both water vapor and air. The foam is used in the roofing projects and the outdoor uses but can be used in any area of the home. CPVC pipe fittings suppliers provide the closed-cell foams along with other equipment and make a home world-class in its architectural built.

Thank you, Allison. We have a split system unit (actually 5) with the heat being propane. The foam guy said that it needed ventilation, so completely sealing the attic wouldn't be a good idea. It sounds like you are saying that the systems need to be vented out of the attic or replaced with some type of closed system. But I shouldn't bother spraying if the plan is to leave the soffet vents open. Is that correct?
The local foam installer that I used here in Hilton Head told me he looked for some peeling back of the foam. This was ensuring that it was at the perfect temperature which helped them maximize their yield (profit). I have open cell foam and it pulled away a little, and did so immediately (within minutes). They went back after they were done to any spots that pulled away too much and filled them with the touch up kit; they were looking for the top edge to roll just a little bit.  http://m.youtube.com/embed/ggLAUsiuI_o
With constant exposure to heat, cold, UV radiation, rain, snow, hail, high winds and possible mechanical damage, a roof can be the most vulnerable component of a building’s exterior. However, a roof’s long-term performance can be enhanced — and major roofing problems avoided — with correct design, quality materials, proper installation and workmanship, and comprehensive care.

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The local foam installer that I used here in Hilton Head told me he looked for some peeling back of the foam. This was ensuring that it was at the perfect temperature which helped them maximize their yield (profit). I have open cell foam and it pulled away a little, and did so immediately (within minutes). They went back after they were done to any spots that pulled away too much and filled them with the touch up kit; they were looking for the top edge to roll just a little bit.  http://m.youtube.com/embed/ggLAUsiuI_o
When choosing a waterproofing and sealing product, we must see to it that we can easily use and apply it using simple tools, including a squeegee or a paint roller. With ease of application, we can be certain that we can achieve hassle-free application and smoother and more attractive finish than other products could give. So when reviewing the products we have featured above, we have made sure that they are easy to apply.

How Much Does Spray Foam Insulation Cost


I had a hole in the drywall in our bathroom that was about 2 in x 5 in that I used Great Stuff to fix. I am impressed with the characteristics of the filler. It filled the hole completely in a few seconds of application. I will warn anyone using it though to make sure you don't fill the hole entirely flush to the wall because this stuff continues expanding after you apply it. I didn't think about that but no big deal really because you can sand it which is exactly what I did, and then applied spacial and paint and it is almost as good as new. For the price this was a heck of a deal because I only used a tiny amount and now am left with nearly a full can. I guess I will have to find somewhere else to use it now. Great product, ... full review

Polyurethane is a closed-cell foam insulation material that initially contains a low-conductivity gas in its cells.[5] As a result of the high thermal resistance of the gas, spray polyurethane insulation typically has an initial R-value around R-3.4 to R-6.7 per inch.[5] In comparison, blown fiberglass typically has an R-Value of only R-3 to R-4 per inch.[6]
In the case you have above the installer wasn't reading his foam. They must be trained to do that as they spray. Temps and conditions are constantly changing thru out the day. Either he wasn't properly trained or if he was,he wasn't doing his job! This is a serious problem with people jumping in to the foam business. A lot of homeowners and builders are looking the best price and end up with someone who doesn't know what they are doing. Hope this info helps. Foam insulation is a great product. It just has to be done right by someone who knows what they are doing.
If you’re not familiar, spray foam is a type of insulation that expands after you spray. The foam expands and seals, avoiding any type of unnecessary moisture (which can create mold) or encouraging pests to eat through your walls. It protects the lining of your house, and even can protect the heating and cooling of your house during those unbearably cold or hot days.

Heatlok®, is a high-performance, versatile spray foam insulation designed for residential construction. Its unique formula incorporates recycled plastic bottles and renewable oils to create high-performance, closed-cell spray foam insulation. This polyurethane insulation combines multiple control layers into a single application, saving homeowners both time and money in construction costs. With our innovative technology, Heatlok is developed with 14 % renewable and recycled content, and is the ideal choice for residential construction. https://www.youtube.com/e/ggLAUsiuI_o?app=desktop
What more is that we also think it is one of the most durable among liquid roof coatings on the market. It can last for several years, working continuously in protecting your roof from outside elements, such as dust, leaves, twigs and debris that would otherwise damage your roof. When it happens, your roof might have leaks and cause discomfort inside your RV. https://youtube.com/e/ggLAUsiuI_o?app=desktop

A: The RV roof coating works by waterproofing, weatherproofing and sealing our RV roofs from elements, including rain, snow, wind and other outer forces. It can also resist impact from leaves, twigs, dusts and other things that would otherwise damage the roof. It also works by reflecting UV rays, keeping the roof from degradation. The roof coating can also prevent leaks, heating and cooling loss and discomfort in our RV. http://kvsprayfoam.com/images/spf-tank-containment.jpg
OK, Peter, I finally went back and read Alex Wilson's article on what he perceives as a serious problem. I haven't seen the full report, but based on the summary he wrote on the Green Building Advisor website, I question the science. It seems to me that he's chosen the wrong metric and he's basing his conclusion on too many assumptions because he doesn't have enough data. You can see my comments at the end of his article.
Fill and seal expanding foam sealant is urethane Fill and seal expanding foam sealant is urethane foam designed to fill large areas quickly and permanently. Uses include filling holes cracks or gaps that require a complete airtight and waterproof seal but are too large to be filled with ordinary caulk. The foam expands approximately 3 times its original ...  More + Product Details Close
I believe customer education is a key to understanding what goes on inside your walls; where a mere 6 inches can separate your comfortable living space and the bitter cold of winter. Some structures are slowly being destroyed by way of insufficient or improperly installed insulation products that do not take into account simple building science. This is where we can help; I believe we can make a difference in the lives of people that live and work in this northern climate.

Spray Foam Exterior Walls


Today’s “third generation” of blowing agents have a GWP of 700 to 1000 which is still remarkably high considering water/CO2 has a GWP of 1. However, innovation from some chemical manufacturers like the Chemours Company have introduced the next generation of HFO blowing agents such as Opteon 1100, which significantly reduces the GWP impact when using closed-cell spray foam insulation products.
This high R-value of 4.45 at 1 inch, polyurethane insulation expands to seal cracks, gaps, and voids in attics, walls, crawl spaces, and ceilings. Agribalance is a three-quarter pound density foam that reduces air leakage by improving energy efficiency, and reducing moisture intrusion and outside contaminants such as dust, dirt, and allergens. As a result, builders can generally install smaller, more energy-efficient HVAC systems and achieve similar, or superior comfort compared to traditionally insulated structures which require a larger, less efficient HVAC system – resulting in higher energy costs.
Allison--would be very interested in your take on the GHG issues of foams, which have received lots of smart commentary recently. To highlight a few: architect Jesse Thompson's comments on Tom's Good vs Bad post on Energy Circle, the very thorough piece by Alex Wilson on Green Building Advisor and Michael Anschel's cautionary diatribe on Remodeling. 
This tropic heat actually is the cause that the steel structure, which most roofs in that part of the world are built on, expands and contracts all the time. By doing so, the sun-battered steel structure causes the roof tiles to dislodge and slowly creates small openings between the roof tiles, through which rain water can run into, creating leaks that can cause much damage to plastered ceilings and electric wiring.
I have never used foam insulation before and this was easy for me to use right out of the box. I had a 4'x8"x8" cavity in my basement that houses a waterline. When the previous homeowner installed this they put no insulation in at all and being that it's an exterior wall in the basement and I live in the Midwest that thing was pushing so much cold air in it was incredibly uncomfortable. Out of the box and job completed in about 5 minutes. Stopped all drafts and created a nice 2" barrier on the wall in which I will install some extra bat insulation over it. 4 stars because the spray isn't very good passed 6-8" from the surface. Make sure you can reach the surface you want to coat. Great for small jobs!
Yes, you're right that all of the problems mentioned above are related to the installer. I didn't try to hide that and even used the word 'installer' in two of the four headings. I can see how you'd think that the title is misleading, but in the end you can't separate spray foam insulation from its installation. Some people have the mistaken impression that if you get spray foam in your house, your home will outperform all others. My point here is that that's not true. http://kvsprayfoam.com/images/KV-Spray-Foam-Metal-Roof.jpg

In the case you have above the installer wasn't reading his foam. They must be trained to do that as they spray. Temps and conditions are constantly changing thru out the day. Either he wasn't properly trained or if he was,he wasn't doing his job! This is a serious problem with people jumping in to the foam business. A lot of homeowners and builders are looking the best price and end up with someone who doesn't know what they are doing. Hope this info helps. Foam insulation is a great product. It just has to be done right by someone who knows what they are doing.

One of the best ways to achieve it is to use the Heng’s rubber coating that can protect it from the elements, including sleet, wind, rain, and snow and UV rays. The product also does well in keeping our roof protected from dirt, leaves and twigs. With such protection received, our roof won’t degrade and we prevent ruining our recreational vehicle investment.

Where To Spray Foam In House

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