Before treating a crawlspace, it is important for pest management professionals to pay close attention to the following areas:
Air Intakes or Faulty Ducts.
The heating and air conditioning system in a home may suck air from the crawlspace and circulate it into living areas. If that air contains termiticide vapor (or odor), it too will circulate throughout the house. This can mean big trouble.
An air intake may be designed into the crawl. Rarely, the furnace will be located in the crawl. In most cases, though, air exchange between the crawlspace and living areas is an accident caused by poorly sealed ducts, or nail holes in ducts that run through the crawl.
Before treating a crawlspace, check that the furnace/air conditioning unit is turned off and that any air intakes in the crawlspace are closed. Inspect the ducts running through the crawl for damage. If you find any, repair it with duct tape or reschedule treatment after repairs have been made.
Cracks and Holes into Adjacent Living Areas.
If a living area is located adjacent to a crawlspace, check for visible and accessible holes to prevent any leaks or significant exposure to people inside. You can further reduce the risk of termiticide vapor being sucked into living areas by (1) using fans to ventilate the crawlspace during treatment until the termiticide dries, and (2) covering the treated soil with a vapor barrier. If there are any signs of leaks after application, the area must be vacated (people and pets) and the site cleaned up.
Down and Dirty: Crawlspace Inspections
The signs of a termite infestation often are in difficult-to-reach areas. Crawlspace inspections can be especially difficult and dirty jobs, and there is a natural tendency to rush through them. But the crawlspace is a likely area to find termites. Skip the crawlspace and you may completely miss the termites.
Unless the crawlspace is inaccessible, all perimeter foundation walls, pillars, interior walls, pipes, chimney bases and hearths should be checked for termite tubes. Cracks between the foundations and sills, in joists, and beams — especially laminated beams — should be examined carefully for tubes.
Use a probe (e.g., a screwdriver, an awl, an ice pick, etc.) to find termite damage in box sills, sill plates, floor joists and all support piers. Damaged wood will contain a mixture of soil and digested wood packed into termite galleries.
Clearance between soil and untreated sills and joists should be at least 18 inches; for beams and girders, at least 12 inches. There should be no wood debris in or on the soil. The crawl should have adequate ventilation if it is not encapsulated. Make note on your inspection diagram of any standing water, moisture on foundation walls or beams, and any leaks from plumbing, particularly under bathrooms, kitchens and utility rooms.
A Wet Crawlspace.
We all know that termiticide labels prohibit treatment of water-saturated soil. Applying termiticide into a wet crawlspace can cause a number of things to happen, all of them bad. If the termiticide never gets a chance to dry out, the solvents do not evaporate, the termiticide remains an emulsion, its molecules do not bind to the soil, and vapors (and sometimes odors) can be generated for months. In the worst case, moving groundwater could carry the still water-soluble emulsion through the soil deeper into the groundwater, into a well, or into a stream.
If a crawlspace appears wet, grab a handful of soil from below the surface and squeeze it. If water runs out, the soil is too wet to treat. The crawlspace will have to be dried out in some way before treatment. Methods might include installation of vents, fans, grade changes, sump pump, or water-proofing. You may be able to treat a chronically wet crawlspace by waiting until late summer when soil moisture in most parts of the country tends to be lower.
Ehrlich Selected to Protect National Landmarks
Ehrlich Pest Control has been selected by the National Park Service to install and maintain effective termite control systems for 14 national historic sites in the Delaware Valley, including Independence Hall.
Ehrlich will be installing the Sentricon System with Always Active technology. Sentricon targets and eliminates the termite colony when termite workers feed on the bait in the stations and then share it with the rest of the colony, eventually eliminating the entire colony, including the termite queen, who can produce millions of eggs during her lifetime.
Ehrlich will be providing services using the Sentricon System with Always Active technology to the 14 sites. Most prominent are the buildings at Independence Square, including Independence Hall, Old City Hall and Congress Hall in Old City Philadelphia. In addition to these iconic buildings under the National Park Service, services will be provided to The Deshler-Morris House and Bringhurst House in Philadelphia. The Deshler-Morris House is also known as the Germantown White House and is the oldest surviving presidential residence, home to George Washington twice during his term of office. Franklin Court homes on Market Street as well as two surviving residences on Locust Street will also be protected from possible termite damage.
This article was reprinted with permission from Techletter, a biweekly training letter for professional pest control technicians from Pinto & Associates. The authors, Sandra Kraft and Larry Pinto, are well-known industry consultants and co-owners of Pinto & Associates.