By Sadia Badhon
Photos courtesy Huntsman Building Solutions
A new insulation application method, where all the spray foam is done from the inside of a large building, can save building owners both time and money. With this method, there is no need to work outside in the cold Canadian weather.
When thinking about the insulation application process on the exterior of the building, with scaffoldings and weather conditions, it is more difficult and costlier in the winter months than in the heat of summer. First off, when applying building envelope products in cold temperatures, while there are many steps one can take to ensure the successful application of the product, the job simply takes longer. Climatic conditions are an important factor that must be considered when selecting building materials. This is not the case with spray foam and this new application process where it is all installed from within the building.
In an exclusive interview, Maxime Duzyk, director of building science and engineering, North America, with Huntsman Building Solutions, spoke to Construction Canada about the new insulation application method.
Tell us more about this new method of insulation application. How is it done?
Duzyk: This new method of insulation is a new way of building. This application method is done in combination with closed-cell spray-applied foam (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 allows for a space between the studs and the sheeting, which facilitates the foam to insulate between the two, thus removing the thermal bridge. It is like the insulation is on the exterior of the building, but it is actually applied from the interior.
The ccSPF along with this new application method 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 complete their part of the project. It saves time spent onsite, is more economical, and provides a higher building envelope quality and durability.
The spray foam used in the interior application replaces four materials including the exterior insulation, the full-surface membrane, fibreglass insulation in the cavity, and the poly. Spray foam acts as an air barrier, vapour barrier, and insulation, so it can replace all these materials. It is not affected by water and is also mould resistant.
What are some of the other benefits of this application method?
Duzyk: As mentioned, every step of winter construction takes longer. Materials will be exposed to rain, snow, and wind. The adhesion of some products will be diminished in colder applications.
When it comes to winter building, there are so many considerations for project success. Temperatures must be constantly monitored. Substrates should have less than 19 per cent moisture content. There might be too much rain, wind, snow, or ice on the substrate. Since insulation products are often sensitive to water, the complete building needs to be watertight before installing the insulation, thus creating delays in sequencing. The exterior air barrier should also be applied before the interior insulation and vapour barrier. Winter projects cost more time, labour, and money to install a building envelope than it does in the warmer months.
And how do you recycle all the foam and all the materials covered with foam? This converts materials that could otherwise have been recycled into materials that cannot be recycled. And we are producing millions on cubic meters of foam insulation every year. What will we do with all the foam in the future? How is this sustainable?
Hi Kyle,
That’s a great question you just asked. Spray foam is very durable and will outlast the building’s lifespan without ever needing to be removed or repaired . Therefore it has high reuse potential, which makes its recycling unnecessary . By blocking air and moisture transfer through the envelope, se amless spray foam insulation also prevents air and moisture-related damage to building components, allowing them to stay in good condition longer and to also be reused during renovations. Again, if they can be reused, they don’t need to be recycled. In fact, the LEED (Leadership in Energy and Environmental Design) green building certification system grants points to projects that reuse existing on-site materials . Keeping building components in good condition with spray foam insulation allows the reuse of existing buildings themselves instead of turning to new construction , which is a main driver of global warming, pollution and resource depletion .
To summarize, sustainable development promotes either reuse or recycling. If materials are kept in good condition and can be reused on site, recycling becomes irrelevant. Reuse is how spray foam contributes to the goals of sustainable development. If you’re interested to learn more, don’t hesitate to visit us at http://www.huntsmanbuildingsolutions.com or contact me directly at mmaalouf@huntsmanbuilds.com.
No interior insulation can be a good insulation. What about continuity of insulation at the slabs or wood framed floors? It is a very poor building envelope solution.
Hi Jito. Thank you for your comment. As described in the article, the continuity is provided by the spray foam insulating the exterior of the structure in the space created by the Z-bar. I can send you our typical details for this assembly so you understand better. It is y very appreciated by architects and builder owners looking for a high-efficiency building envelope.
How exactly is the thermal bridge removed when the studs are now creating a larger thermal bridge? Wait for the steel stud condensation marks on interior drywall.
Hi Davendra. Thanks for your comment. As described in the article, the thermal bridges are removed by the spray foam insulating the exterior of the structure in the space created by the Z-bar. I would be glad send you our typical details for this assembly so you understand better.
This might be a decent solution to insulate a building in the winter if there is a plan for a continuous air/water resistive barrier and continuous insulation/cladding system i.e. EIFS applied over the exterior sheathing in the spring. Hygrothermal modelling required.
Hi Dave. Thanks for your comment. There is no need for EIFS system with this assembly but, of course, our details ask for a water-resistive barrier on the exterior of the assembly. Our U-value performance results will be published soon. Let me know if you would like to receive our typical details.
I think spray foam is/has being outlawed in Vancouver due to it’s extremely harsh environmental impact. So how is this article good news at all?
Hi Joe. thnaks for your comment. Spray Foam is not banned in Vancouver as we insulate projects constantly. Our new Heatlok Soya HFO product has a very low global warming impact (less than 1) compared to rpevious versions of the product. I would be glad to discuss this sbject further with you.
Hi Joe. Sorry for the misspelled response. Here is the correct one. Thanks for your comment. Spray Foam is not banned in Vancouver as we insulate projects constantly. Our new Heatlok Soya HFO product has a very low global warming impact (less than 1) compared to previous versions of the product. I would be glad to discuss this subject further with you.
Though the S101 is listed in the bullet points, the actual fire-resistance rating is not noted. What is it and where is it listed? In practice, there would need to be more attention to this issue than given to the subject in the article. Also, the thermal bridge is not eliminated.
Hi Peter. Thanks for your comment. The CAN/ULC S101 testing is not actually for fire resistance but for compliance with article 3.2.3.8 of the NBC for buildings higher than 3 stories. We have the UL listing EW25 for this assembly. As for the thermal bridge, it is removed by the spray foam insulating the exterior of the structure in the space created by the Z-bar. I would be glad to share our typical details with you.
Hi Maxime, We represent BASF WALLTITE and have used a similar approach with WALLTITE with good results in terms of acceptance and buildability. In our system, the exterior sheathing is supported by intermittent thermal clips that have a continuous hat channel or similar attached to it. This provides better effective R value compared to a Z girt. In most projects there are some hidden areas that may need to be sprayed from the exterior but this is fairly limited. Overall this type of system has great potential as it is much more efficient for the installers and it will help to improve the code compliance compared to typical cavity wall applications.
Hi Michael. Thanks for sharing. We do have that option with our HEATLOK SOYA HFO system as well. The thing is, the clips are much more expensive so we prefer having many options available to help builders and owners lowering the construction cost, when it is needed, while keeping a high energy efficiency building. While clips might perform better regarding effective R-value, there are also ways to comply with new energy efficiency requirements without increasing construction costs. We have many projects completed with this assembly and they involved a great collaboration between the general contractor, the architect and our team. We have a strong presence on site so it helps everyone working on the project. As a leader in the industry, HUNTSMAN BUILDING SOLUTIONS is in the process of testing many assemblies for U-value to better guide designers in choosing the best assembly for their needs and to comply with building code requirements.