SPF Helps Home Stand Up to 200 MPH Winds

By Stephanie Marie Chizik

“The only way that you can really build an energy-efficient house is to have an air-tight house,” said homeowner Ralph Stork. For Stork, energy efficiency was merely a byproduct of his real concern: creating a home that could withstand hurricane-force winds.

So finding an answer to the question — how do you build an air-tight home? — wasn’t optional like it is for some. For a retiree who wanted to spend the rest of his life in a new South Carolina home, finding a way was mandatory.

Wind-Resistant Roof

To seal the roof, Stork chose a method of adhering his concrete tiles to the building’s metal trusses.

He started with six-inch-thick insulating concrete forms (ICF) for walls — reinforced with rebar — and steel trusses every 24 inches. With “U”-shaped hat channels (which do the same job as a batten) placed horizontally every 14 inches, the overlapping 17-inch-long concrete tiles would be secure. Although in normal construction these tiles are screwed or nailed onto the hat channels or wood trusses, Stork wanted something stronger.

“I wanted to do an attic that becomes part of the conditioned air space,” Stork said. “Everybody thought it was radical.” Radical, though, it was not. Stork attests that this type of roof has not only been used in Europe and Asia for the past 300 years, but it’s also been used recently in California. To the South Carolina community where Stork built, though, this was new.
He chose to adhere the underside of the tiles to the steel with Polyfoam Products, Inc.’s two-pound, closed-cell SPF called FRF200.

“With Polyfoam, the concept is to lay down two little patties and set the tiles down on those patties,” Stork explained. “With two patties of a closed-cell Polyfoam, it’ll withstand 140 mph winds. My thought was, if two patties are going to do 140 mph, I’ll use this adhesion foam on the underside to the point where I have seven inches of foam. I don’t see how anything can blow them off.”

Seven inches of foam on a 2,400-square-foot home is a lot of foam!
Practice Makes Perfect

Over the course of three weeks, Dave Faulkner, the Marketing Development Manager for Polyfoam, arrived at the Stork house to try out different ways of applying SPF to the tiles. Faulkner believed that it could take a foamer one to two days to complete this size job if it were done without experimentation. With slight modifications, the process may also be used in environmentally conscious building practices.

“I believe that this is an ideal application for the industry,” Faulkner said. “This building, with slight modifications, can be a net zero energy home. In fact, this house may be classified as a net zero.” But, since that wasn’t Stork’s primary motivation, for this job, it wasn’t Faulkner’s either. Instead, they were focused on sealing the house.

Before the foam went on the roof, the builder notified all other trades that the SPF was going to be applied that day. With an empty site, Faulkner and his assistant were able to get to work. Wearing gloves, eye protection, fresh air supply masks, and harnesses 100 percent of the time while spraying, Faulkner climbed up his rolling scaffolding.

Faulkner sprayed one eight-foot by eight-foot section at a time.  When he finished applying four passes of one to two inches of the foam under the tiles, he let his helper know in which direction to roll the scaffolding, and he got ready for the next section. With a two-to-three-minute cure time before the product “skinned over,” Faulkner was able to release his finger on Polyfoam’s nitrogen-pressurized foam system. The RTF1000 is a refillable system where the attached gun mixes two components in a chamber inside the gun.

He continued to roll around the house until the entire underside of the roof tiles had six to eight inches of foam.

“Now, the attic is part of the conditioned air space,” explained Stork. “And the entire house is now air tight.” 
   
Success in the Savings

With the foam applied, Stork was able to get his home’s interior ready for move-in day. Stork — and Faulkner — couldn’t be happier with the results.

“[This system] holds the roof on, gets insulation into the roof, and also makes the house air tight,” said Stork. When skeptics ask him why he chose SPF over other cheaper insulations, his response is surprising.

“When you add it all up, it’s not expensive. It reduces; you reduce the cost of your air conditioning and the cost of your heating,” he continued. “I don’t have a heat pump or a furnace, and I have smaller utility bills.” The savings don’t stop there!

The stability of the structure may save Stork in the future, too. Polyfoam helps his home withstand winds up to 200 mph. At 60 mph more than the average Polyfoam house, the Stork house should withstand a Category Five hurricane! The roof has yet to be tested with winds that high, but Stork’s confidence in the foam is unwavering.

“We’ve already proven the fact that you can’t get them off with a sledge hammer,” Stork said. “I was curious, and, well, you can’t!” That’s one way of showing faith in your house. But with expectations that the structure will stand for decades to come, being curious about just how strong it is should come as no surprise. “I think my roof is good for 100 years,” Stork continued. With no wood deck or felt paper in the house, it’s an unusual and enduring home. “You never have to fix them, never have to repair them. It’s going to be here for a long, long time.”

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