Fortunately, BASF has developed solutions through its latest technologies and polymers that help address many of the challenges of the building envelope industry. "Our products enable our customers to manufacture products that help reduce the amount of labour, service a broader applications window so that it can be used year-round, and also make sure that they're the highest performing products to help achieve some of the strictest building codes," says Antonia Chan, Marketing Manager, Construction Solutions, Dispersions & Resins North America.
BASF has developed a portfolio of polymer dispersions that have been expertly designed and formulated to be optimized in different types of building envelope coatings:
- ACRONAL® 4667 — formulation into roof coatings;
- ACRONAL 4848 — formulation into roof coatings;
- ACRONAL 4511 — formulation into air barriers; and
- STYROFAN® NX 1492 — formulation into waterproof coatings.
"Each of these polymers have their unique properties to optimize the performance in each of those respective coatings," Chan says.
Customers who are manufacturing these coatings for the latest design needs within commercial building construction will be able to position their products better for the industry.
Each of these polymer dispersions are designed to help improve energy efficiency in an aspect of the building envelope.
"Moving from the 1980s to the 1990s and to today, newer building codes are designed specifically with energy efficiency in mind," says John Kelly, Technical Specialist for Building Envelope.
BASF's polymers and dispersions enable manufacturing of solar reflective roof coatings.
"There are different initiatives around the globe to achieve more white roofs to help reflect heat away from urban centers and more industrial environments. Our technologies enable formulation of the solar reflective roof coatings to help builders and architects achieve those goals," Chan says.
When it comes to roof coatings, customers are looking for products that are UV resistant for a long period of time — a far cry from older roofs that were coated with tar and asphalt that would oxidize and crack over time.
"They have to sit out all the time in the sun and they have to be able to perform under harsh weather conditions," Kelly says. "Now you can have a longer lasting roof. You have products like ACRONAL 4848, which is designed to create roof coatings that go over lots of different of types of materials."
Kelly adds that some customers have considerations beyond UV resistance for roof coatings, so BASF produces polymers that meet a wide range of demands.
"Based on the needs of the customer, we have tailored polymers that can go over any substrate — membranes such as TPO and EDPM, as well as concrete, metal and asphalt. So, if you want to coat over an old roof, we have products that do that, too," he says.
Air barriers and waterproofing
A large portion of the performance of building envelope coatings is dictated by the type of polymer that's used.
BASF's polymer dispersions ACRONAL 4511 — for the formulation of air barriers — and STYROFAN NX 1492 — for the formulation for waterproof coatings — are all about improving energy efficiency for building envelopes.
"In air-conditioned buildings, they're designed to move a certain amount of air through the building over a period of time. In newer buildings, in order to capitalize on the highest possible efficiency, you need to control the ingress and egress of air and moisture from that building. So, this is where the fluid-applied air barriers especially come in to play because they seal so well," Kelly says. "If there is any water ingress from rain into buildings, that's humidity that you're going to have to remove, and the HVAC system will have to work double-time to remove that water. So, waterproofing is key to controlling the building environment, in order to best manage and make the most use of the energy used to cool and heat that building."
These polymer dispersions are used to formulate coatings that are sprayed on and adhere to multiple substrates. A façade of a building could be concrete, a wood type like oriented strand board, or an industrial type with a fiberglass mat like gypsum sheathing.
"Fluid-applied air barriers maintain or control the amount of moisture and air that go through the building. So, if you can limit that and fix it, you will be able to have a more energy efficient system, because you'll have to cool and heat less overall air moving through that building, which leads to lower overall energy consumption."
These coatings are designed to be semi-permeable, allowing the building to breathe a little.
"BASF's ACRONAL 4511 is designed specifically to be highly flexible when formulated into an air barrier coating. And this is necessary due to building shifts as well as broad temperature swings. They have to pass a pretty stringent ASTM crack bridging test (ASTM C1305)."
Not only do these polymers need to hold up under those tests, they also have to be able to seal around the fasteners that you put through it.
"You'll have to necessarily poke holes in your air weather barrier. So, it needs to be able to seal around any fasteners that you put through it. We have designed those polymers to also seal around any punctures. That's another important test to pass (ASTM D1970)," Kelly says.
Like with roof coatings, customers also demand some degree of UV resistance.
"Our customers demand some degree of UV stability up to about a year," Kelly says. "It's not designed to be an exterior paint, but it has to, for a short period of time, function like one."
"Our polymers are designed to really help facilitate an effective waterproofing coating because you want it to prevent water from going into a building and keep it healthy and resilient. And so, water resistance is a property that our technology helps facilitate the strength and flexibility of that membrane. And then, also, adhering to lots of different types of building substrates," Chan adds.
Building in longer lifespans
By utilizing the highest performing polymers, customers can formulate fluid-applied coatings to significantly increase the longevity of their buildings.
"What does that mean? Well, it means that they have to coat less, but it also means that the amount of energy and time you have to spend maintaining that building goes down," Kelly says. "Let's say buildings are warrantied for roughly 20 years, if you can extend that life another 10 years, then you've just moved the needle significantly on the amount of time, effort and energy you need to spend on maintaining all that. This is why we continuously push the envelope on the development of these technologies."
To learn more about BASF's latest building envelope solutions, visit our applications page.