Increasing the quality of construction while providing a radon free environment - top 7 HFO spray foam questions answered

What if there was a better way of installing spray foam insulation? Here are the top seven questions often asked about how HFO spray foam contributes to sustainable and innovative construction methods while also protecting residents and tenants from harmful Radon gases.


By, Maxime Duzyk

Maxime Duzyk with Huntsman Building Solutions
Maxime Duzyk
Director of Building Science and Engineering
Huntsman Building Solutions

Builders and architects with projects on the go are looking for ways to meet energy efficiency and sustainability requirements, and to improve their work on the job methods to ensure building project success while reducing delays and costs. With labor shortages and a large amount of construction and retrofit projects, builders and architects are looking for ways to increase their productivity without reducing quality and meeting green building standards. There is also a need to select products that can be installed at various temperatures and that will not be affected by weather elements like extreme wind, water and snow.

What if there was a better way of installing spray foam insulation? A way for builders and architects to differentiate themselves by using innovative techniques that will add value to their offerings while increasing the durability and quality of their constructions? Here are the top seven questions often asked about how HFO spray foam contributes to sustainable and innovative construction methods while also protecting residents and tenants from harmful Radon gases:

  1. How is HFO based spray foam different compared to its previous version with HFC?

Hydrofluoroolefin (HFO) is the blowing agent used for spray foams. Some closed-cell spray foams (ccSPFs) are made with recycled plastic and renewable materials. Compared to Hydrofluorocarbon (HFC) versions, HFO are greener products with a lower Global Warming Potential. HFC products have a GWP of around 900, which means a 900 more than CO2. HFO products have a GWP of less than 1 which is 99.9% lower than HFC products. This helps builders and architects attain more LEED credits for their projects, and this green aspect makes HFO products much more attractive to the building design community. This is in addition to the fact that HFO does not have any substance that deteriorates the ozone layer. The HEATLOK Soya HFO product developed by Huntsman Building Solutions is the first and only spray foam system with a product-specific, Type III EPD which is independently completed and verified. The objective assessment delivered through this EPD is key to ensuring an informed choice in the specification of sustainable insulation. Heatlok Soya HFO has lower embodied carbon that most insulation products and lower operational carbon emissions than other insulation products in the industry over its service life. It can save up to 110 000 kg of CO2 over its service life (75 years) compared to fiberglass insulation. It also contributes to USGBC LEED v4 credits and other green building rating systems.

Huntsman Building Solutions’ High Performance Building HEATLOK Soya HFO

As of January 1st, 2021, HFCs are prohibited in the manufacturing and importing process for spray foam. This means that every spray foam product now must incorporate the HFO blowing agent. Not every manufacturer is ready for this transition, and some have not met the deadlines. Some have HFO products, but they do not meet the new standard CAN/ULC S705.1-15 and therefore, do not meet building code.  Huntsman Building Solutions made sure that its HFO product meets not only the new regulations but also the most stringent standards and testing.

  1. What are the advantages of HFO in the building application process?

The advantage of HFO product is also in its building application. The total thickness applied can now go as thick as 8’’ in a single day. The application thickness is still 2’’ per pass but the waiting has been reduced to only 30 minutes between the first two passes and the third and fourth. This decreases the installation time. An 8’’ roof application, which becomes more and more common with the new energy efficiency requirement, can be completed in a single day. So, HFO is a better product than previous HFC versions, it’s better for the environment, has the most updated testing behind it and has more advantages in its application process.

Then there’s a new way of building called D-Max Wall assembly, and this is done in combination with ccSPF, where the wall is composed of regular steel studs, but instead of installing the exterior sheeting directly on the steel studs, a Z-girt is installed horizontally on the studs and then the sheeting is installed on top of the Z-girts. This contributes to space between the studs and the sheeting, which facilitates the foam to insulate between the two, thus removing the thermal bridge. It’s like the insulation is on the exterior of the building, but it is applied from the interior.

DMax-Wall Interior Application by Huntsman Building Solutions
Huntsman Building Solutions’ DMax-Wall Assembly After The Interior Application

The ccSPF along with this new type of assembly removes the need for the spray foam applicator to work outside, leaving other building envelope trades to work faster on the exterior of the building and to efficiently complete their part of the project. It saves time spent onsite, is more economical, and contributes to a higher building envelope quality, performance and durability.

The spray foam used in the interior application replaces three key materials including the exterior insulation, the fibreglass insulation in the cavity, and the poly. The spray foam acts as a combination of an air barrier, vapour barrier, and insulation, so it can replace all these materials. Nor is it not affected by water and is also mould resistant.

  1. Where is HFO based spray foam most used?

Without a doubt, the rim joist is the place where spray foam is most used. Why? Because it is the place that is the hardest to perfectly seal. With the floor structure meeting the exterior wall and the foundation wall, it’s hard to get a perfect continuity with the air and vapour barrier, and the insulation. Spray foam makes the insulation of the rim joist very easy, using only one material. That’s the reason why many builders have now extended this application to the complete building or home basement. If it works for the rim joist, this self-adhesive and self-sealing product can be used on the foundation walls and under the basement slab as well. As residential and building basements are a prone area for soil gas intrusion like Radon and building codes now require measures to protect from it, why not use a product that can do it all?

  1. What is Radon? How can spray foam protect from it?

It’s a radioactive gas released by the breakdown of uranium in the soil. It is natural and it’s pretty much everywhere in different concentrations. It’s odourless, tasteless, colourless and it’s silently killing 3,200 Canadians per year. It’s the number one cause of lung cancer in non-smokers and there are homes and buildings with elevated levels of Radon everywhere in Canada right now. Fortunately, the building codes now have implemented measures to reduce the points of entry for Radon in homes.

Huntsman Building Solutions Spray Foam Application for Radon in Buildings
Huntsman Building Solutions’ HEATLOK SOYA HFO As Radon Barrier in Buildings

Some spray foams, like Huntsman Building Solutions’ HEATLOK Soya HFO are tested for Radon diffusion and at only 1.25’’, it performs 65 times better than a 6-mil poly which is the material that is proposed by the code to act as the Radon barrier. The place where the protection is the most important is below the slab. Usually, 2’’ of spray foam is installed directly on the crushed stone and the slab gets poured directly on top. There is no need to use tape or sealants as the foam seals all pipes or perforations of the slab. The thickness of the foam makes it much harder to puncture than 6-mil polyethylene (for example, when workers are walking on it during construction). The compressive strength is also ideal for this application. You then can get the full basement insulated with only one seamless product from one rim joist to another. It’s like having a tailored insulation that can adapt to any shape or form and self-seals everything, keeping Radon outside the building envelope. The quickness of installation is also very impressive, a complete basement (rim joist, foundation walls and under slab) can be completed in only half a day. This is much quicker than other products where you need many workers to trim and install the insulation, tape the poly, seal it with caulking which also leaves room for errors, which does not happen with spray foam.

  1. Where can these applications be used in residential, commercial?

These assemblies can be installed in both residential and commercial construction. Many commercial projects are using spray foam for walls and are now integrating the under-slab application as it saves a lot of time on site. In residential construction, as mentioned, spray foam can insulate the complete house.

  1. Who in the industry is seeking these types of applications?

For commercial, the requests come from the clients, architects and general contractors that want a better assembly and who want to save costs. In residential, the demand mostly comes from homeowners looking for sustainable products and for high-performance homes. Sometimes, homeowners will request spray foam in their roof and walls because they already use it in their basement for Radon protection and they may have a volume rebate for the total house.

  1. Do you foresee more demands for HFO based closed-cell spray foam product?

With the new energy efficiency requirements, the thickness of insulation is bound to increase, along with the construction costs. Spray foam is a solution in the commercial market to keep a reasonable construction budget while meeting the new requirements. In residential construction, it is also a solution to meet the ever-increasing requirements, but also provide a durable and Radon free building envelope with a product that does not have an impact on global warming and is made from recycled and renewable materials.

Maxime Duzyk is the director of building science and engineering with Huntsman Building Solutions. He holds a background in architecture and has been in the spray foam insulation business for the last 10 years. Maxime is involved with different building envelope committees and associations in North America like CSC, SFC, SPFA, CCMC and ULC Standards.

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