Improper installation of spray foam, particularly closed-cell types, can lead to roof damage from expansion and contraction, increased condensation, and difficulties with repairs or mortgages.
Insulating Your Attic with Spray Foam
While spray foam won't cause any damage to the roof shingles, some contractors will still void the warranty because they are stuck in that old way of thinking.
The chemical aspect of spray foam makes it very hard for standard insurance companies to provide coverage. Most standard lines insurance carriers want to write the risks with no liability not spray foam contractors that manufacture plastic every day in the field.
Due to its quick and straightforward installation process and affordable pricing, spray foam insulation is quickly becoming a popular product. However, there is a chance that the insulation in this product will start to shrink over time, which will lessen its insulating capabilities.
Spray foam insulation is one of those many factors that can throw up a red flag to a mortgage lender. For a lender, your insulation matters because it affects crucial metrics such as the home's saleable value and energy efficiency rating.
Some Buyers May Be Uncertain Of Spray Foam Insulation.
If they don't know the contractor who installed it, they may worry that the foam was installed by people who didn't know what they were doing. Other buyers have heard negative stories about spray foam insulation.
Directly against electrical wiring or fixtures: Spray foam insulation should not be applied directly against electrical wiring, fixtures, or recessed lighting unless they are rated for contact with insulation. Contact with insulation can cause overheating and pose a fire hazard.
While spray foam insulation can make a home more energy efficient, its downsides often out-weight its benefits. If spray foam insulation isn't installed correctly or is used in the wrong setting, it can cause all sorts of problems, from reducing ventilation to rotting wooden roof beams.
Mold and mildew can begin growing behind the insulation which can go unnoticed until it's already become a huge problem. This often happens when the spray foam isn't installed correctly and space is left between the insulation and the wall, which allows moisture in and gives mold the perfect place to grow, unfettered.
By applying spray foam insulation across the entire roof deck, these gaps are sealed, preventing moisture entry. Consequently, this sealing eliminates the need for attic ventilation to remove moisture since the air barrier formed by the spray foam already keeps it out.
Spray foam insulation provides an excellent air seal, reducing the workload on the HVAC system by minimizing air leaks. This not only extends the lifespan of the HVAC system but also improves comfort and energy efficiency, qualities that can boost a home's marketability and resale value.
Aside from its relatively high cost, it has been reported as reducing ventilation, with humidity and dampness resulting in the deterioration of structural timbers. Spray foam insulation has also come under criticism for being: Difficult to remove once it's been installed.
Removing spray foam insulation is messy and labour-intensive. It usually involves cutting the roof foam as far as possible without damaging the materials around it and then scraping off the rest by hand. It's also very likely to cost more to remove the spray foam than it was to have it installed in the first place.
It's important the spray foam insulation used in roofs is breathable, as timber needs to breathe and this will ensure no problems such as rot occur. If you've heard of spray foam rotting your roof, it's likely to be the result of a spray foam contractor using polyurethane spray foam instead of Icynene®.
For instance, insulating the attic's roof deck typically covers a much larger surface area than insulating the floor. This difference can significantly impact the total cost. To give you an idea, the average cost to spray foam an attic in an existing home typically ranges from $5,100 to $10,300.
Spray foam roofs are generally expected to last around 20 years at installation. The roof will last much longer than 20 years, but this is the standard warranty period. This all depends on the thickness of the foam and the coating, and applying more of either of them will generally extend the warranty term.
The Cons
The main things you need to worry about with spray foam roofs are small installation windows, overspray, maintenance, and repairs.
Insulating your attic with spray foam can increase your energy efficiency, make your home more comfortable, and even improve your air quality. These benefits are due to the 2-in-1 feature of spray foam as an insulation and an air-sealing product. It can be expensive if you want to insulate your attic with spray foam.
The discussion around the dangers of spray foam insulation often includes the potential for respiratory problems, particularly during the installation process and while the foam is curing. Furthermore, some spray foams can off-gas volatile organic compounds (VOCs), leading to indoor air quality issues.
Independent chartered building surveyor, Geoff Hunt said due to government initiatives open cell spray foam has gained popularity in recent years. But he called for 'caution and refusals on higher-risk applications' as mortgage lenders struggle to assess spray foam.
While it is hugely useful, it should not be used to solve all problems. One such example is electrical boxes. Expanding foam shouldn't be used in these locations as it could cause jams that would be expensive to repair. So avoid using it around sockets or light fixtures, or any electrical components in the property.
If you don't remove wet insulation, water will freeze and contract in the winter, which can cause cracks. This isn't just with spray foam; freezing and cracking can happen with any roofing system. The cracking opens the roof membrane, which allows for more water to enter the roof system in the future.
Spray foam can provide the thermal, air, and vapor control layers in both new and retrofit construction. Unvented roof strategies with open cell and closed cell SPF insulation sprayed to the underside of roof sheathing have been used since the mid-1990s to provide durable and efficient building enclosures.
Recent media and industry reports suggest some homeowners have found it difficult to remortgage or sell properties that have spray foam insultation. If installed incorrectly, spray foam insulation may lead to condensation which can affect a roof structure.
If closed cell spray foam has been used rather than open cell spray foam insulation, the main problems are that it can put stress on supporting roof timbers, can restrict air circulation in the roof and cause condensation, which in turn causes roof timbers to rot.