For the past three years, the pest management industry has raised concern about spray polyurethane foam (SPF) insulation and the challenges it poses in detecting termites early.

SPF is increasingly used in the crawlspaces, attics and walls of new and existing homes, mainly in the Southeast, to improve energy efficiency. Pest management professionals say the foam makes it difficult, if not impossible, to visually inspect for termites and wood-destroying beetles and fungi when it covers key inspection areas like box sills, floor joists and where foundation walls come in contact with the soil.

Visual inspection with sounding and probing has been the industry standard for subterranean termite detection for 50-plus years and in many cases is mandated by regulation. Some states also require use of a moisture meter for wood-destroying organism (WDO) reports.

Because spray foam application makes visual inspection difficult, some PMPs are voiding the termite damage warranties of clients who have retrofitted their homes with the foam. They’re walking away from new customers who have it, and are refusing to write termite/WDO inspection letters for real estate transactions for homes with SPF.

Termite activity in the SPF observed during the August inspection from the joists and joist header by Location 5 of the UGA tests.

The Spray Polyurethane Foam Alliance (SPFA), which represents foam installers, has asserted that newer technologies can help detect termites when spray foam is applied. These technologies include moisture meters, acoustic emission (listening) devices, microwave technologies, infrared cameras, air sampling for carbon dioxide and methane emissions, and specially trained termite-detecting dogs.

Kurt Reisenberg, executive director of SPFA, has said that termite professionals have not kept pace with technological advancements and instead continue to rely on old inspection techniques. In the February 2019 issue of PCT, Riesenberg said, “They need to enter the modern day and potentially use more advanced, more technically capable techniques to do their job.” He said he was not aware of scientific studies that proved these technologies did not work with spray foam.

PUTTING TECH TO THE TEST. That got termite experts wondering if there might be some truth here, despite their intuition otherwise. Still, if the technologies could be proven useful, then PMPs would have more success inspecting for termites in structures with spray foam.

Thus was born the Spray Polyurethane Foam/Termite Detection Demonstration Project at the University of Georgia in Athens. The month-long project was an opportunity to put some of these technologies to the test. It was led by entomology professor and termite expert Brian Forschler and was funded by the Georgia Department of Agriculture, which regulates structural pest management in the state and is tasked with protecting consumer interests. Participants donated their time and the University of Georgia Physical Plant Division donated use of a building that was scheduled for renovation.

For the study, SPF foam was applied to shelter tubes at locations 0 and 20; and on the sill, joist header and beams at locations 5, 15, 25 and 30. Two types of SPF were applied at each location: closed cell SPF at 2-3 inches and open cell SPF at 6-8 inches thick.

On July 16, 2019, five termite inspectors, each with 20-plus years of experience, examined the tall crawlspace of this campus building, which had a moisture problem and active subterranean termite infestation. Participants individually inspected the crawlspace using visual inspection, moisture meters, infrared cameras and/or a microwave motion detector. They each identified areas of termite activity, marking these places with red arrows. No live termites were seen.

Professional foam installers then applied closed- and open-cell spray foam to six places where termite activity was documented. The following day, the inspectors came back to evaluate the effectiveness of the same devices on the foam-covered areas. They returned on Aug. 15, 2019, to inspect the areas again — this time also using a borescope — and to remove the foam.

WHAT THEY FOUND. The demonstration project is not a scientific experiment that can be replicated, as every termite infestation in the field is different. It did, however, provide objective observations, said experts, that confirmed two things. First, an obvious one: Termite inspectors cannot perform a visual inspection through spray foam.

“Before everything’s foamed up you can see trails; you can see certain patterns on the wood that give you a visual indication there might be an issue with termites. But once everything’s been covered in foam you have absolutely no clues. It’s like looking at a landscape full of snow. You don’t know what’s underneath it,” said Ed Freytag, an entomologist with the City of New Orleans Mosquito, Termite & Rodent Control Board who participated in the project.

Second, they said the demonstration confirmed that the technologies tested (with one limited exception) do not make it easier to find termite activity under spray foam. And none is a standalone substitute for visual inspection.

A diagram of the crawlspace from the building floor plan with blue lines delimiting the interior foundation walls that define the crawl, green lines approximate distances (in feet) of the crawlspace foundation and the red line indicates the location of doorway providing access to the crawlspace. The location numbers discussed in the report are posted in white boxes in red with Locations 0 and 20 on the hollow block wall in the southeast and southwest corners, respectively, and Locations 5, 15, 25 and 30 on the joists and joist headers on the south and west walls, respectively.

Moisture Meters — The project evaluated six moisture meters. Subterranean termites require humidity, and moisture meters can help identify specific areas most conductive to termite activity. According to Forschler, the devices tested did not consistently indicate termite infestations behind SPF insulation.

The moisture meter on the Termatrac T3i was the only device to discern a difference in moisture between areas where termite activity had been visually confirmed and the surrounding foam. If the foam was more than 2 inches thick the device wasn’t able to detect moisture behind it, but if it was 2 inches thick or less, it could detect moisture behind the foam, explained Termatrac Sales and Training Manager Rick Wakenigg, who participated in the project.


The demonstration crawlspace had an existing moisture problem, which could have made it difficult for the devices to distinguish between moisture in wood caused by termites and the moisture already there.

Infrared (IR) Cameras — The two IR cameras tested could not see termites through foam or even in infested wood not covered by foam, said Forschler.

Jim Fredericks, vice president of technical and regulatory affairs at the National Pest Management Association, who read the report but did not participate in the project, wasn’t surprised by the finding. IR cameras read differences in temperature. “A termite is cold blooded so it’s going to be the same temperature as its surroundings,” he said.

Plus, temperature readings taken on the crawlspace surfaces were never more than a +2 degree Celsius difference whether on wood, block or foam. The crawlspace was neither heated nor cooled so everything was generally the same temperature, including any moisture brought in by termites that in other conditions might show as a cool spot in a warmer wall.

“The infrared camera really was kind of a bust,” said Freytag.

Borescope — A borescope is an optical device with a flexible tube and lens; some connect to smartphones. One month after the foam was applied in the crawlspace, Freytag used a borescope to drill ¼-inch holes in the SPF and wood to determine if termites were present. In one area, hundreds of termites were observed.

Freytag knew where to conduct the destructive sampling from previous inspections. To randomly drill holes on SPF-covered surfaces would be impractical and an infestation might be missed.

Microwave Motion Detector — The only device that detected termites through the SPF was the Termatrac T3i microwave motion detector. “I think this demonstration clearly showed that you can pick them up through it,” said Forschler.

But because the device has a 4-inch detection window, experts said is impractical to use it to inspect an entire SPF-covered crawlspace or attic. “Once you have an idea of where they might be then you could likely use that technology with SPF,” said Forschler.

Wakenigg of Termatrac suggested using the device in “hot spots” where termite activity often is found and where a visual inspection finds areas of dark or discolored foam. “It’s not an inspect-all tool. It doesn’t take the place of inspections. It helps assist with inspections and what’s going on behind those areas,” he said.

NEXT STEPS. Forschler presented the demonstration project report to the Georgia Structural Pest Control Commission (GSPCC) on Nov. 12.

Chris Gorecki, GSPCC chair and vice president of operational support at Rollins in Atlanta, had been waiting for the report to see if one of the technologies might be a solution to detecting termites behind spray foam. “It doesn’t seem like any of those things is a solution at this point to replace visual inspection,” he said.

As such, the Commission plans to use the report and other data to ask for changes to the state building code, said Gorecki. Georgia currently requires termite inspection gaps at the top and bottom of SPF-covered foundation walls. It also requires the box sill that sits atop the foundation wall to be air sealed so most builders cover it in foam, which is easier than applying caulk to the cracks.

This means the box sills of new homes often cannot be inspected. The same is true of existing homes retrofitted with SPF. “You can’t see anything in that area and that’s probably the most critical point in my opinion,” said Gorecki. He said one proposed code change is to use expandable foam in the cracks of the box sill and then cover the area with removable batt insulation, which inspectors can lift up to inspect.

NPMA has a task force working to amend the international building code to provide more visual access for termite inspection.

Amending the codes will help, but individual pest control companies also must decide how (or if) they want to deal with termite inspection, protection and guarantees in structures with spray foam, said Gorecki.

In the future, Forschler may test an acoustic emissions device and possibly a termite-detection dog (neither could be located for the demonstration project last summer). He said the gas detection technology referenced by the SPFA has not been proven useful for termite detection.

The ultimate goal of the demonstration was to bring the pest management and spray foam industries closer to finding a resolution that works for all parties, especially consumers. “The spray foam people want to protect the consumer; we want to protect the consumer. We just need to figure out a way to continue in the right direction,” said Rick Bell, vice president of government affairs and industry stewardship at Atlanta-based Arrow Exterminators, who participated in the project.

“That might be a big lift but that’s what we’re sincerely trying to do,” he said. “Honestly, spray foam is a great product. It has a lot of wonderful applications but it cannot be used where it hinders our ability to do a visual inspection because termite protection is pretty important, too,” said Bell.

SPFA REACTION. Officials at the Spray Polyurethane Foam Alliance (SPFA) were still reviewing the project report in-depth but raised some initial concerns.

“SPFA appreciates the effort put forward by this team of researchers but suggests that there are some potential fatal shortcomings to the study that indicate scientific failures,” said Riesenberg in an email.

He said parts of the report should be evaluated and replicated by appropriate professionals, including equipment technology representatives and professionals to assist in the equipment selection, training, use and interpretation of results.

“Before this study is considered legitimate, or a basis for any drastic code change or elimination of SPF insulation as an option, SPFA would suggest that other professional research facilities replicate this work and have this report submitted to a peer-reviewed journal or conference proceedings for publication. Without peer review, anyone can do or say anything because it does not have to stand up to the test of qualified scrutiny,” wrote Riesenberg.

A specific concern raised by Riesenberg was the use of the FLIR infrared system, which he said has been successfully used in Australia for more than a decade and is now part of the Australian standard AS3660.2/2017 for termite management. SPFA is in discussions with FLIR to confirm if the proper IR camera was used and inspection protocols were followed in the study. The particular camera used (E6) in the study may not have been sufficiently sensitive or have good enough resolution to be effective in termite detection, potentially disqualifying the results presented, said Riesenberg.

In addition, SPFA is in discussions with Termatrac to develop multiple-sensor devices that could accelerate complete inspection of the band joist in a reasonable time period, and is assessing new, unconsidered alternative technology solutions, wrote Riesenberg. “These alternative technologies are proven and viable supplemental investigation technologies that should be considered by (PMPs) looking to do closer investigation of areas that their natural skills and visual inspection have suggested may benefit, despite the conclusions of this study,” he said.

Finally, the applied thickness of the SPF products used in the study may have exceeded the insulation R-value requirements for buildings in warmer climates, especially near the foundation-framing interface, said Riesenberg. Typically only R13 insulation is needed, meaning that about 2 inches of closed-cell SPF and 3.5 inches of open-cell SPF should have been used as representative samples. The use of hybrid systems (flash and batt) consisting of a thin closed-cell SPF layer and fibrous insulation also was not tested in this study, he wrote.

The considerations put forward in the study have a substantial, mutual impact on both industries. Riesenberg said it is unfortunate that neither SPFA nor the spray foam industry were advised of the study or of its results until two days before the report was presented at the GSPCC meeting.

Riesenberg called this “another disappointing missed opportunity for the pest management industry to transparently and fairly work with the spray foam industry, as we attempted to do (in) providing our own documents for review and comment earlier this year.”

He was referring to the Termite + Spray Foam guidance document for SPFA members. Originally published in October 2017, the document was updated in 2019 by SPFA, which sought input from pest management professionals and the National Pest Management Association. NPMA ultimately withdrew its support of the document.

The author is a frequent contributor to PCT.