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?

Spray Foam Garage


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.

I did a LOT of prep before using this product. Cleaned, vacuumed, installed additional insulation etc etc etc. This spray foam was easy to work with, and did it's job as it was supposed to. If you are curious, this kit was purchased because - every "foam insulation company" I contacted either did not call back (due to no interest) OR this was too small of a job. That is why I went DIY on this one, that and: I was advised by one of these companies that they have a minimum $2k job because ... (insert your answer here, but I will choose that everyone needs to eat).
The drawback to spray foam insulation is it's been known to cause certain health issues such irritation of the eye and the gastrointestinal and respiratory tracts. Direct contact can cause inflammation to the skin, and some individuals have been known to break out in a rash on the arms, chest and neck area. Spray foam insulation has also been linked to a few cases of hypersensitivity pneumonitis. This condition can cause:
Sealection® 500 has been Demilec's flagship product for more than 20 years, and has positioned Demilec as an industry-leading spray foam insulation manufacturer. As an environmentally-friendly product, it delivers superior performance, energy savings, and is an excellent return on investment for architects, builders, contractors, and homeowners, making it the ideal choice for insulation.
Note: The practice of foam insulating the attic has raised eyebrows in the building industry because "standard" roofing techniques call for the attic to be ventilated; however, in a vented attic situation it will become approximately 130 degrees in the summer. There's no reason for an air-conditioning and vent-ductwork to have to work in that type of severe conditions. By applying Icynene right on the underside of the roof deck, the severe temperatures no longer exist in the attic. In short, the attic is now a "conditioned" space of the house that is just as comfortable as any other room in the home. This is called a "Compact Roof", which means you can frame right up against it. The one drawback of using expanded foam on the inside of the roof is that this will cause the temperature of the shingles to rise, but how much is not yet known. And how much damage a rise in temperatures could cause is debatable.
SPF insulation applied by professionals is usually described as either a high- or low-pressure foam and is available as either open- or closed-cell. Each type has advantages and disadvantages depending on the application requirements. The comparison chart below can be helpful in explaining or understanding which type of SPF insulation is best suited to a specific application.

A: It can be applied in the similar manner that we apply paint. We can use a paint roller to apply it without any hassle and use of special tools. You can also check the specific manual of instructions from the maker for particular directions. You should also check if it requires single or double coating or the use of a primer before its application.
Spray foam insulation helps lower utility costs because it blocks heat and cold from the outdoors. Recent studies by the U.S. Department of Energy state that around 40 percent of all energy is lost through poor insulation. Spray foam insulation is able to insulate homes at least 50 percent more than traditional insulation products. Spray foam insulation can also provide protection against moisture, which otherwise leads to the unwanted development of mold and mildew. And it can also be used for noise reduction as well. In fact, spray foam is good for homes and buildings in which outdoor noise can be a distraction.
While the R value will vary, most ocSPF products have an R value of around 3.8 per inch. Unlike medium-density closed-cell SPF, ocSPF is not a vapour barrier. When installed at 5.5 inches or more, ocSPF does act as an air barrier. It is often used for interior walls because it provides sound reduction by blocking and absorbing air leakage. It is usually only recommended for indoor applications.

The complete line of JM open- and closed-cell spray foam insulation solutions provide superior thermal and energy performance, as well as advanced air, moisture and sound control in any climate. These products can be used in interior and exterior walls, unvented and vented attics, floors, ceilings and crawl spaces. Plus, using spray foam can reduce air leaks and create a more comfortable, energy-efficient home – meaning you could see more energy savings every month.
Another thing we love about the Liquid Roof is its ability of not being damaged by freezing and other extreme temperatures. You will also appreciate its ability of staying flexible for a longer period of time. Did you know that it could also contract and expand as you roof moves? That is one of the things to look for when shopping around for this kind of product we found in the Liquid Roof.
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. 

One of the key differentiators between traditional insulation materials and spray foam insulation is the latter’s ability to insulate and air seal. Foam insulation provides an air barrier to wherever it is applied to help mitigate air leakage from the building. Air sealing the building envelope with sprayed-in foam insulation also helps address moisture ingress to reduce the risk of mold and mildew growth as well as the formation of ice dams in colder climate zones during the winter months.  When you compare foam insulation with traditional fiberglass insulation and cellulose insulation, sprayed insulation minimizes air infiltration, it assists in limiting moisture vapor from entering and escaping the home, which in turn reduces the load on heating and cooling systems. Below is a video that compares fiberglass, cellulose and open-cell spray foam in terms of insulating and air sealing value. https://www.youtube.com/watch?v=ggLAUsiuI_o&app=mobile
I have used the Froth-Pak 200 to air-seal rim joists--the area above the foundation wall in a basement. The first time I used it I did not shake the canisters well enough and the foam did not cure properly. Don't just shake the box for a few seconds. I take the tanks out of the box so I can shake/invert each tank for a minute or two. You will be able to hear the chemical sloshing around in the tanks. Also, don't ignore the recommended temperature for application--around 75 degrees F. http://youtube.com/watch?feature=youtu.be&v=ggLAUsiuI_o

During colder months, 2 component foam is very sensitive to temperature variances. Per product instructions, both tank temperatures need to be above 70°F (21°C) for at least 24 hours prior to use. All application surfaces should be clean/dry and above 60°F (16°C) prior to application. Variance outside of the recommended temperature can affect foam yield and performance.


When it comes to insulating the house, fiberglass tends to be the common form of insulation. However, after comparing fiberglass and spray foam insulation, it’s shocking how fiberglass tends to be the lesser of the two. Although it has deemed reliable over the years, there are way more benefits to insulating your home with spray foam. One of those benefits includes regulating the temperature of your house.

Spray foam is a chemical product created by two materials, isocyanate and polyol resin, which react when mixed with each other and expand up to 30-60 times its liquid volume after it is sprayed in place. This expansion makes it useful as a specialty packing material which forms to the shape of the product being packaged and produces a high thermal insulating value with virtually no air infiltration.

How Much To Charge For Spray Foam Insulation


However, coating asphalt shingles and built-up composition roofs requires more caution. The National Roofing Contractors Association’s (NRCA) director of technical services has stated "The roofing industry is aware of a number of issues that could have negative consequences for field application of coatings over asphalt shingle roof systems. Anyone considering this type of application should be aware of the concerns so they can weigh them against the benefits claimed in coating product promotional materials."[2]

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. 

Most closed-cell spray foam is now formed using hydrofluorocarbon (HFC) blowing agents that have high global warming potential, partially or completely offsetting the climate benefits of the energy savings they can offer. In the United States, HFCs are scheduled to be phased out by January, 2021. A few spray foam suppliers have started supplying spray foam blown with hydrofluoroolefin (HFO) blowing agents without this problem as of early 2017.[14]


Was hesitant to buy this product because of some of the reviews but glad I did. It does just what it says and we even got the square footage out of it. You just need to read ALL the directions first and it wouldn't hurt to read some of the helpful hints in some of the reviews. It does only cover 1 inch at 600 square feet and is extremely easy to apply. Very satisfied customer!
Open-cell is also known as half-pound foam. It has an R-Value of 3.5-3.6 per inch, and its density is bout 0.5 pounds per cubic food. Low-density foams like these are made partially from raw biological materials Carbon dioxide or water is also used in the makeup. Open-cell uses far less material than closed-cell, but its R-Value is lower. Also, open cell requires a vapor retarder (like gypsum wallboard) and is riskier when used for roof sheathing. It's not highly recommended that you use open-cell insulation if you live in a cold climate unless you have that extra barrier. You should also compare how much money you spend versus how effective the open-cell insulation is wherever it's installed.

Spray Foam Cost


Starting a new build (1 1/2 basement walkout), all 2x6 exterior walls w/ brick veneer in CZ3. Above grade, would like to do spray foam in 2x6 walls, 1/2" or 1" of rigid foam board on the exterior, and a 1" air gap. Will this require a house wrap or can I do w/o the rigid foam and go with a housewrap? Also, any recommendations about insulation strategies for the finished basement. Thanks!
Before you decide on spray foam or another method of insulation, it's important to understand the superiority of spray foam compared to traditional materials. When compared to fiberglass batts, spray foam offers nearly double the R-value per inch, achieves air-sealing and insulation in one step, won't be damaged by mold or moisture, and won't settle, compress, or otherwise be damaged to the point it needs replacement.

During colder months, 2 component foam is very sensitive to temperature variances. Per product instructions, both tank temperatures need to be above 70°F (21°C) for at least 24 hours prior to use. All application surfaces should be clean/dry and above 60°F (16°C) prior to application. Variance outside of the recommended temperature can affect foam yield and performance.


There are two main types of spray foam to consider: open-cell and closed-cell. Open-cell spray foam has a lower R-value per inch and because of this, typically a lower price tag. The soft, low-density material is used for interior applications. Its high permeability allows for moisture to pass through, which contributes to bi-directional drying of the assembly, but it may not be ideal for all applications or climates. 
You probably have some familiarity with spray foam insulation, and you may have even used the foam that comes in pressured spray cans at home improvement retailers. This foam is know as one-part foam, meaning that it is one continuous mixture that is simply applied to the area in need. One-part foam is frequently used for sealing small gaps and cracks.
Repair and seal roof penetrations, tears, open seams, etc. using Elastek 103 Crack & Joint Sealant and reinforce with polyester roof fabric as necessary. In larger or deep ponding areas, apply Elastek 500 Puddle Plaster to fill in areas that hold water. Avoid using plastic roof cement. Serious ponding should be referred to a roofing contractor. Blisters in previous coatings may be opened but these areas must be allowed to dry-out completely. Blisters in the roofing ply should be left alone unless likely to break. Caulk and reinforce open seams, roof penetrations, cracks, and tears. These are potential leak points so work carefully and thoroughly. Use fabric to build flashings around roof edges or roof penetrations, and to reinforce various coating repairs. A polyester fabric is used because it will stretch with the coatings. (Fiberglas fabric is not recommended.) Fabric is normally cut to extend three inches beyond the repaired area in all directions. The coating is applied to the roof surface and the fabric is immediately pushed into the wet surface. An additional coat is applied over the fabric and the patch is allowed to dry. If your roof has stucco parapets, examine them for cracks along the sides and top. These areas often permit water to enter the wall and can cause blisters and wrinkles in the roof surface. Repair with Elastek 103 Crack & Joint Sealant. If you do not have parapets, examine the metal drip edge for a tight seal with the roof membrane. Use 4″ or 6″ roofing fabric covered under and over with Crack & Joint Sealant to seal cracks along drip edges, penetrations, and open seams.
During colder months, 2 component foam is very sensitive to temperature variances. Per product instructions, both tank temperatures need to be above 70°F (21°C) for at least 24 hours prior to use. All application surfaces should be clean/dry and above 60°F (16°C) prior to application. Variance outside of the recommended temperature can affect foam yield and performance. https://youtube.com/v/ggLAUsiuI_o?version=3
2. I talked to a building product supplier for WALLTITE spray foam, he is suggesting to use 2" or 3" of closed cell spray foam in the joists areas instead of the batts insulation. He says it will work with outboard rigid insulation. There is a location of a cantilevered floor area with steel beam so I may need to use spray foam to protect the steel beam. I would then be convenient continue to spray in the floor joist cavities and then apply 5" of polyiso outboard of the bottom cantilever floor sheathing.

DID YOU KNOW? Spray FOam insulation out-performs conventional insulation materials because they (conventional insulation materials) trap still-dry air and if that air moves or becomes wet, the thermal resistance can drop by 50%. Spray Foam protects against air infiltration, which can increase energy costs in buildings by 10 to 40%. Eliminate these drafts and live in a more energy-efficient, comfortable and healthier building by choosing spray foam insulation.


c) Make sure that the over expanded access is properly removed from the walls. We had a junior cutter taking too much off by bending his saw into the cavity. Look closely at the inside wall corners, and ceiling/wall corners to make sure that the foam is properly removed flush with the studs. If it has not been cut back flush it may lead to uneven drywall finishes . https://youtube.com/e/ggLAUsiuI_o
I live in Baton Rouge LA with a very old and drafty house. There is no blockages in the walls between the crawl space and attic. Lots of critters just come on in. I would like to used closed cell sprayed under house to warm up floors and block moisture. I would like to spray closed cell into attic, but am afraid of enclosing attic due to moisture build-up. Can I spray closed cell against the attic floor in same way as installing bats, thus leaving my venting the same as it always has been. Other ideas? Thanks.
Excellent kit for insulating a house. Slow rising foam takes longer to insulate an area as you must do it in layers 1" thick. Any thicker can overheat the chemicals and prevent a proper cure and off-gassing. Recommend purchasing a second suit and nozzles so you can use it multiple days to achieve the thickness desired for the highest R value. Seals up and insulates much better than traditional fiberglass. The sound suppression is noticeably different. Used it to insulate the ceiling above our bedroom. The sound is remarkably more quiet than the fiberglass insulation we had before. The only down side is the weight of the containers. Using a smaller kit would be easier to handle and move around when spraying a ceiling in an attic. A word of caution, use plywood that spans at least 2 joist per container when spraying in an attic to hold the weight.
Although spray polyurethane foam has many advantages over other types of insulation, spray foam installation isn’t foolproof. Some builders have reported problems with sloppy foam insulation. For example, some installers have been known to begin spraying before the chemical components are up to temperature, which can affect component mixing and foam performance. When components are poorly mixed, or mixed in the wrong ratio or at the wrong temperature, cured foam has been known to shrink away from rafters or studs, leaving cracks. Some installers rush through their spraying, resulting in voids.
Spray foam can also contribute to more comfortable interior spaces and less costly monthly energy bills. The U.S. Environmental Protection Agency estimates homeowners can save an average of 15 percent on heating and cooling costs by air sealing their homes and adding insulation in attics, floors over crawl spaces, and accessible basement rim joints. 

Roof coatings made with acrylics, urethanes or asphalt soften under the stress of ponding water or snowpack. Eventually, these roof coatings will bubble and peel away from the substrate, leaving your roof vulnerable to leaks, rot, and decay. However, GacoRoof’s 100% silicone formulation is designed to stand up to whatever the elements dish out. Silicone will withstand areas of ponding water without softening, bubbling or peeling from the substrate. Acrylic, urethane and asphalt roof coatings decompose and wear away from the stress of harsh sunlight, UV rays, and freeze-thaw cycles.

How Much Is Spray Foam Insulation Installation

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