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.
The average price to cover 200 square feet with a foam insulation kit will run between $300 and $600 (about two to three kits). Inside these kits is something called Icynene, a foam made from two liquids that are heated and pushed through a gun on the can. When Icynene is released, it expands up to 100 times its size as it hits the surface area you're covering. These can contain a lot of gasses, making its installation a dangerous process. Even low-pressure sprayers can be harmful to homeowners' health.
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.
There is a significant price difference when it comes to using foam insulation to insulate a new versus older home. Spraying insulation inside a newly constructed home is easier because the installation company can ensure the insulation will work effectively and design it for optimum defense against sound, heat transfer and utility costs. Installing spray foam in older homes that contain existing insulation can cost additional time and money -- it is not usually recommended as compared to weatherization or an energy aduit.
Sealection 500 is a cutting-edge formula of open-cell spray foam insulation, which expands 120 times its liquid volume to insulate and seal all cracks, gaps, and joints with a single application, and is easy to install and finish. It has dramatically increased energy efficiency for millions of residential and commercial property owners. This translates to a high-performing product for builders, shorter application, and finishing times for contractors, and lower energy bills for homeowners and commercial building owners.
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]
The problem was that the installer was doing his first spray foam job ever, and the thickness of the insulation varied from zero (visible roof deck) to about 9". Unfortunately, good average thickness doesn't cut it. The coverage needs to be uniform because a lot of heat will go through the under-insulated areas. (See my article on flat or lumpy insulation performance.)
once the foam is installed correctly, it is a inert plastic not much different than the foam cushions you sit on. there is not a health rick unless you have off ratio uncured foam that has not mixed properly. the foam is absolutely a health risk in its raw forms before it is mixed and cured. You should not be in the building without proper respirators and eye protection. The spray foam industry should be controlled and regulated by the same standards, testing and inspections that framing ,electrical and plumbing are. until that happens then you will have idiots with spray rigs ruining peoples homes and ruining the market for honest foam contractors that know how to price a job fairly and complete it correctly.
Acrylic coatings are typically applied in two coats, with the second running perpendicular to the first. 1 gallon per 100 square feet is a good estimate for these coatings, as they do not need to be applied nearly as thick as many other coatings. These coatings can be sprayed or roll-applied. Acrylic coatings generally require a re-coat within 2-3 years of application.
Roof coatings can add 25 years to the service life of a roof and reduce the amount of discarded roofing materials that end up in landfills. The infrared image on the right shows 175 °F (79 °C) on the uncoated (black) section of the modified bitumen roof. The coated (white) section is 79 °F (26 °C). Field studies have shown that cool roof coatings can lower rooftop temperatures and reduce air conditioning bills.

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.
Get the Power to Seal & Insulate Perfectly in Just 5 Minutes. The Foam it Green Promise: 1>Simpler, Easier, Faster Spray Foam 2>No Special Skills or Know How 3>Professional Results or Better Saves You Time, Money and Hassles. Delivers to your door, ready to use. Just follow the simple instructions. Saves Energy with High R-value Closed Cell Foam. R-Value of 7 in Just 1 Inch. Provides a seamless air barrier in 1 step. This Kit Provides Approx. 602 Square Feet at 1” thickness of cured foam. Class I E-84 Fire-Retardant Foam that meets building code specs. This Anti-Microbial Formula passed the stringent ASTM G-21 test for preventing mold growth on the surface of the foam. Includes everything you need to complete your project. Weighs 120 lbs, including steel canisters pressured with nitrogen. Orders with multiple kits on it may ship via LTL instead of UPS. The LTL carrier calls to arrange a convenient delivery time. Usually Ships Same Business Day. See Manufacturer for returns and warranty policy.
The video below is from a house near Charleston, South Carolina that I visited recently, and you'll see that the homeowner in this case didn't get his money's worth. I knew immediately when I walked into the attic that something was wrong because it was hot up there. In a properly insulated spray foam attic, the temperature won't be much higher than the house temperature. 
The average price to cover 200 square feet with a foam insulation kit will run between $300 and $600 (about two to three kits). Inside these kits is something called Icynene, a foam made from two liquids that are heated and pushed through a gun on the can. When Icynene is released, it expands up to 100 times its size as it hits the surface area you're covering. These can contain a lot of gasses, making its installation a dangerous process. Even low-pressure sprayers can be harmful to homeowners' health.
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.

How Much Better Is Spray Foam Insulation

This is more common with closed cell foam, but it happens with open cell foam, too. Since closed cell foam has a higher R-value per inch, installers generally spray 2" in walls and 3" in rooflines to meet the energy code requirements of R-13 and R-19, respectively. (I'm not going to dive into the energy code here, but these numbers apply to many climate zones, the latter being allowed under the UA tradeoffs rule. See the Energy Nerd's blog on this topic if you want to argue.)
We service the entire Central Texas Area including Waco, Abilene, Fort Worth, as well as Granbury, Aledo, Weatherford, Eastland, Hico, Hamilton, Brownwood, Comanche, Glen Rose, Meridian, Cleburne, Mineral Wells, Graham, Breckenridge, Decatur, Eastland, Ranger, Gorman. We have done work as far away as Colorado, so don't hesitate to call if you're outside this immediate area.
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.
High-pressure systems can be used to spray all three types of spray polyurethane foam. Of the three types of spray foam used in building insulation and weatherization, the high-pressure, two-component spray foam is most likely to be used on larger projects such as a new building construction or renovations. SPF applied with a high-pressure system tends to adhere tightly to the entire structure which helps avoid sagging or detaching from its position. It can also provide a seal against air and insects.
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.

How Much To Spray Foam Crawl Space