I am an Architect in Toronto. I am designing a new roof addition to a row house building. Because of existing conditions and the shape of the new roof. It may be easiest to use closed cell spray foam within the areas of the joists. My question is when spray foam is used in this situation do I need to worry about how the joist members may be thermal bridges? It is not common to provide a little bit of rigid insulation to protect the joist members? The additional layer of outboard insulation will require an extra layer of plywood above the insulation which will add to cost.
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Carefully examine the roof membrane (surface material) for cracks, tears, blisters, evidence of ponding, exposed foam, and open seams. If already coated, evaluate the condition of the coating. Pay particular attention to areas around roof penetrations (vents, skylights, pipes, etc), ponding areas, cracks in parapet walls, and the attachment of roof membranes to parapet walls. Roofs should be in good condition to warrant coating.

Spray polyurethan foam does effectly prevent all six of these heat transfer methods from occurring. These should be the mechanisms by which you judge insulation, in addition to their R-Value. If you're uncertain about installing spray foam insulation, Energy Star has a map that recommends levels of insulation by R-value and cost-effectiveness in the United States.


I am on my third project with foam it green. I like the simplicity of it, the color blending to make it green, it alerts you quickly if something is wrong with the blending so you don't waste alot of valuable material. Follow the instructions closely, put in the prep time and you will have no issues. It seems most people's negative comments have to do with not following instructions or guidelines. It is about as close to point and shoot as you can get but there are still some essential details that need attention. The only complaint I have is the fragility of the gun, last project I cracked one on accident but luckily needed two kits to finish the project so I had a back up, but I was more careful to gently lay the gun down between applications.

Spray Foam Metal Building


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?
I've seen this only once, and it was with closed cell foam, but I've heard of it happening with open cell foam, too. I don't know the details, but I've heard it could result from a bad batch of chemicals, improper mixing, or too high a temperature. Whatever the cause, it's not a good thing. The photo below shows how the spray foam pulled away from the studs. A little bit of uninsulated area like that adds up to a lot of heat loss/gain when the whole house has that problem, as it did here.
Part of that guidance will be explaining that interior, two component foam is applied with the professional using specific personal protective equipment (high-pressure foam is installed while using a respirator, for example). It is encouraged that professionals explain clearly to customers that this equipment, coupled with certain work and engineering practices, including ventilation, is used to minimize exposures to the chemicals used to make SPF during the job.
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.
Roof coatings are easy to install. Smaller roofs in good, serviceable condition can be a weekend do-it-yourself (DIY) project. Larger roofs with leaks and ponding water issues should be coated by a qualified professional. Additional roof coating products, such as foam or coatings designed for seams, may be required underneath the main coating layers. Supplement coating products are used to reinforce damaged or leak-prone problem areas.[3]
Spray foam is a very specialized packing material, often required for use in shipping valuable fragile items. Engineered packaging principles are designed to protect sculptures, vases, large fossils, lamp bases, busts, computers, furniture, chandeliers and other objects of unusual shape. By virtue of the liquid foam expanding by up to 30-60 times the volume of its liquid state, it efficiently protects almost any size, form and weight.

I recently did a remodel project for my basement using spray foam insulation. The original builder has used fiberglass, but I wanted the best insulation i could find. We chose closed cell foam because it blocks moisture from getting into the house. It took one day to install and was fumey for about 3 hours. It was pretty cool watching it being done. It comes out as a liquid and then expands rapidly into a foam. It's quick! Then they took a types of saw to shave it flat with the wall studs so we could then go ahead and drywall.
Check with the coating manufacturer who may be able to suggest applicators who have used their products and have familiarity with the application. Another option would be to interview contractors and ask specific questions about their proven ability to install roof coatings. Contractors affiliated with the National Roofing Contractors Association (NRCA) or local roofing contractor trade associations typically are more knowledgeable. Consult those groups’ websites for contractors.
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.
For example, a hybrid solution of spray foam and fiberglass batts or rolls combines the air-sealing and vapor-retarder benefits of foam with the economical thermal performance of fiberglass. Another option might be to install spray foam in places that are hard to reach or seal, such as rim joists, the attic floor, and eaves, and then install fiberglass batts and loose-fill in the in the open areas, greatly reducing any draftiness while helping the project budget. Incorporating spray foam into hybrid solutions enhances the building envelope and seals efficiently at a reasonable cost.  http://youtube.com/e/ggLAUsiuI_o?app=desktop
Spray foam comes in two flavors, open cell and closed cell, and provides both parts of the building envelope - the insulation and the air barrier. The building envelope should completely surround the conditioned space, and the insulation needs to be in contact with the air barrier. Since spray foam is both insulation and air barrier, proper alignment of insulation and air barrier is guaranteed.
Spray foam is a very specialized packing material, often required for use in shipping valuable fragile items. Engineered packaging principles are designed to protect sculptures, vases, large fossils, lamp bases, busts, computers, furniture, chandeliers and other objects of unusual shape. By virtue of the liquid foam expanding by up to 30-60 times the volume of its liquid state, it efficiently protects almost any size, form and weight.
Sporadic cases of hypersensitivity pneumonitis (HP) have also been reported in workers exposed to isocyanates. The symptoms may seem like the flu, with fever, muscle aches, and headaches. Other symptoms may include a dry cough, chest tightness, and difficult breathing. Individuals with chronic HP often experience progressively more difficult breathing, fatigue, and weight loss. Individuals with acute HP typically develop symptoms 4–6 hours after exposure.[4]
Builders often turn to high-density SPF when high insulation values and strength are needed. As its name implies, this foam has a denser structure than either of the other SPF types. Therefore, it does not expand as much as lower density foams and requires more material to cover and insulate any given space. This spray foam is often an excellent choice for roofing or other exterior insulation because of its seamless, monolithic nature. High-density SPF can also help reduce energy costs significantly over a roof’s lifetime due to its thermal resistance properties. It also offers increased protection against air and water infiltration and strengthens the structure to which it is applied. The bond that SPF forms to the roof can increase a building’s resistance to wind uplift, which can help reduce damage experienced during periods of high wind.
Sean, thanks for jumping in and answering John's questions. About choosing the right foam, I intentionally avoided the open cell vs. closed cell foam debate. I did this partly because it's worthy of an article all by itself, but mainly I didn't include it because, despite all the warnings the two sides issue about the other, I've never personally seen a problem caused by using open cell where they should've used closed cell or vice versa. I'm sure things like that happen; I just haven't seen it yet.

We live in middle TN and had our house foamed last year. We noticed recently that some of the foam was shrinking and seperating from the floor joists. We contacted the installer and he informed us that the manufacturer had a problem with a batch of foam during the time frame we had our house sprayed. The contractor wasn't sure if we had the recalled batch installed in our house or not. He said he would check the batch numbers and let us know. He seems like a nice guy promising to do whatever it takes to fix any problems. Do we trust him, however, to be truthful about the batch number? Do we have any options for finding out the information ourselves? I inspected the entire crawl space of the house and noticed approximately (5) areas that were seperating and a couple areas where the foam didn't adhere to the block. Do I assume by it being so infrequent that it is nothing to be concerned about? My concern is the walls that are not capable of being visually inspected because of sheetrock.

How Much More Expensive Is Spray Foam


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.

The problem you saw with the closed cell foam pulling away like that is due to the heat of the foam was to hot. It was actually curing out and making foam before it could adhere to the wood. The installer wasn't reading his foam correctly. He should of stopped and turned down the heat on his hose temp. Also installers have to be aware that as the sun rises and the temp in attics rises the subtrates get hotter as well. This will cause the installer to adjust his heat when installing the foam as the temp changes thru out the day.  


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.

According to the Department of Energy, an estimated 20 to 40 percent of a home’s utility bill could be going to waste from drafts and air leaks around openings. As temperatures cool and energy costs rise, the positive impact of energy efficiency on a building comes into focus. Air can enter and escape a structure through every gap, compromising the building envelope. Adding the right insulation and air-sealing will close these gaps, keeping interior spaces comfortable and reducing energy bills. 
R-value, the thermal resistance measure of insulation, varies between all insulation products whether they are fiberglass, cellulose, open-cell spray foam insulation or closed-cell sprayed-in foam insulation. Generally speaking the rule of thumb is the higher the R-value, the greater the insulating power.  Focusing on spray foam insulation materials, there is a difference between the two main types. According to industry publication, Fine Home Building, the R-value for open-cell spray foam is between R-3.5 – R-3.6 per inch. However, there are open-cell spray foam insulation products actually offer R-3.7 per inch such as Icynene Classic and Icynene Classic Max. The open cell structure of low density foam insulation means the R-value is lower than its closed-cell counterpart. Nevertheless, open-cell spray foam does offer superior and consistent thermal insulation and air sealing properties.

How Much For Spray Foam Roof


Jennifer, I'm not an expert on the health effects of closed cell foam. A lot of people live in houses with closed cell foam and have no health problems from it, at least not short-term, acute problems. I do know of one person who had it removed from her crawl space because she was convinced it caused her dog to get sick, but I know only what she told me.  

Spray Foam Existing Wall


I used this product to seal and insulate my rim joists as I am finishing the basement. The builder used R13 batt insulation when we built the house 3 years ago. I use a dehumidifier to control moisture in the basement which is below grade. The setting I use is 55%. The dehumidifier kicks on periodically and requires emptying every few days. Since using the foam all around the house on the rim joists and sill plate, the dehumidifier has stayed at 50% for over two weeks since spraying and rarely turns on anymore. I also put the original R13 batt insulation back up after the foam cured.
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 .

How Much Spray Foam Garage

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