HOW MANY HOLES does it take to fill the Albert Hall? I honestly don’t know—ask Sgt. Pepper’s Lonely Heart’s Club Band! 😉 But I do know roughly how many holes it takes to perform a perimeter termite treatment on the long walls of our sanctuary hall.
Namely, more than 250! That’s the number of holes that were drilled and filled this week in our sanctuary. And that was for the upper half of those walls only.
Below the jump, this post explains the why, how, and what of the treatment. Of course, with accompanying photos (courtesy of Ruben Carrillo).…
What Happened to Tenting the Building?
In our last episode (back in May), we were contemplating tenting and fumigating the entire premises. I tried hard to make it work. However, although everybody involved made a good-faith effort, I was unable to get all of the stakeholders on the same page at the same time.
That’s perhaps unfortunate, for I have read in authoritative sources that no legal (i.e., reasonably safe) spot treatment with insecticide kills 100% of termites, even in the vicinity of the treatment. But perhaps we could at least slow them down a lot! So I asked our termite contractor to recommend the next best thing to fumigation. They said that would be a perimeter treatment.…
What is a Perimeter Treatment?
A perimeter treatment injects termite poison into the voids within the walls that form the perimeter of a building.
Even though a perimeter treatment is known not to be super effective, it still seemed worthwhile given the high likelihood of infestations in a 74-year-old building like ours. Our termite contractor, who had grown up in Venice and whose father before him had been in the same business, told me that it would be very unusual for us to NOT have termites.
But in fact we pretty good circumstantial evidence of that in the south wall, where termites were documented already in the 2003 Historic Structure Report. It noted,
Termite frass [telltale evidence] was observed near the wood sill line at the foundation wall near the east end of the south wall at the first floor.
In other words, there was a known infestation in the south wall of the sanctuary, about 2' off the floor, next to the first few rows of seats. Unfortunately, it remained untreated until last year (2021). At that time, only what was openly accessible (through cracks in the plaster) could be treated. So any termites farther inside and higher up in the wall were not necessarily eliminated.
Drilling and Filling
The treatment consisted, first, of drilling small holes into the voids between the wall studs, 16" apart, at 3 different levels along the length of the wall.
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| Lowest level = just below the plaster divider |
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| Middle level |
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| Top level = at ceiling |
The second step was to inject the termiticide. It comes in a pressurized can with a nozzle.
The third step (not shown) was to patch the hole with caulk. And the final step (not yet done) will be to paint over the white patches.
We chose not to treat the area near the floor level at this time, because we are expecting to do restoration work there. Once we open up the wall(s) for that reason, we can treat for termites more effectively at that time.
About the Termiticide
Termidor FOAM creates a dry foam that can be applied into voids. The foam expands rapidly to a ratio of 30:1. In about 5 seconds, 1 oz. of product becomes approximately 1 quart of foam.
The termite contractor had at first recommended a different product, Premise Foam, which seems to work well enough for direct application on accessible infestations. (It’s what was used earlier this week in the roof side chambers.) However, for a perimeter treatment (dealing with inaccessible termites), I requested Termidor instead. The contractor replied that he thought it wasn’t as safe, but he soon obliged after doing a little checking into the matter.
In saying "What about Termidor?” I wasn’t trying to be impertinent. He’s the professional. It’s just that I’d recently come across a couple of scientific studies that made an impression on me. Let me explain…
Effectiveness of Termiticides
The Structural Pest Control Board (SPCB), which is part of the state Department of Consumer Affairs, licenses and regulates structural pest control businesses and professionals. Back in 2007, it commissioned two university teams to investigate the effectiveness of 6 termite treatments on the market. The final reports from 2009 are posted on the SPCB website.
One of those reports, “Evaluation of Chemical Localized Treatment for Drywood Termite Control,” did various lab tests on those 6 termiticides, using identical sample pieces of wood, and a control group, and so forth. It found that Termidor consistently provided the best results, unlike Premise. For example, Termidor (but not Premise) was among the compounds that killed the fastest and most thoroughly — more than 90% of untreated termites that came in contact with it. Furthermore, termites would inadvertently carry it back to their nest, where it would eventually kill additional termites. In contrast, they seemed to avoid eating the Premise, despite its marketing claims. The report noted that Termidor seemed especially well suited for situations in which the termite galleries (infestations) are inaccessible to direct treatment (like our walls!).
The other report, “Field Evaluations of Localized Treatments for Control of Drywood Termite Infestations in California,” conducted before-and-after monitoring on professionally applied spot treatments in buildings. None of the chemicals tested were shown to be super effective. More tellingly, measuring effectiveness precisely in real-world conditions turns out to be very difficult. (Termites are quite good at keeping a low profile!) However, the investigators did make a clear recommendation, by reasoning from basic principles:
What can be done to improve local treatment performance? … At a minimum the active ingredients in products for remedial control must be non-repellent, slow acting, and have the capacity of [being passed on] to fellow nest mates.
The report’s authors then noted that Termidor (but not Premise) had demonstrated those desirable biological properties. In short, this second report supported the first report’s preference for Termidor.
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