1. Advanced Termite: Treatment, Measuring & Foundations
Part 1 Treatment Basics
In the United States there are more than 50 termite species. Of those 50 species 2 types are the most
problematic in California. In California drywood termites can live in all types of wood, and can be
found in any part of a house. Western subterranean termites however are ground dwelling and must
have a connection to the ground except in extreme cases. Subterranean termite colonies are the
larger of the two, while the termites themselves are physically smaller. Subterranean termites are
attracted to sources of moisture, such as areas around plumbing leaks and other ongoing structural
moisture issues. Drywood termites however, are called that for a reason. Moisture does not attract
them and they will infest wood that is relatively dry.
For drywood termites, fumigation is quite often the most reasonable and complete solution.
Fumigation with (Sulfuryl Fluoride) vikane gas kills termites in both visible accessible areas and those
hidden inaccessible areas. Drywood termites missed during an inspection will die as a result of a
properly done fumigation along with termites that were found. Fumigation therefore has two cases
where it absolutely is necessary: when termites extended into inaccessible areas, and when drywood
termites are believed to exist in inaccessible areas. Fumigation is not intended for use with most
species of ground nesting termites including western subterranean termites but is applicable to all
drywood termite infestations where it can be physically accomplished.
Local treatments for drywood termites include many different options and are done by drilling holes
into infested wood then injecting the wood with termiticides. Holes can vary in size, and types of
equipment used to inject can vary as well. Some technicians use modified B&G sprayers with injector
tips, while others inject with ready to use products such as Premise Foam. The more complicated
injection equipment is made to work under pressure and can force products deeper into termite
galleries. This includes on vehicle tanks, standalone foam machines and many other forms of
complicated equipment.
Western subterranean termites are not killed by fumigations. In fact, their treatment is not similar to
any type of drywood termite treatment. Since termite colonies find their way into structures by
traveling under the foundation of most houses, the foundation is where most treatments begin. This is
referred to as a post construction foundation treatment. Treatments are completed by applying
product to the soil along the foundation so that it can leave a residual and protect the foundation. In
cases where a structure is built on a slab foundation holes usually are drilled 1 ft apart along the
foundation with most products to allow application of the soil below. Some products can be used with
holes 16 inches or even 18 inches apart. Where the soil is exposed the most appropriate treatment
option is the trench and treat method. This method involves digging a trench along the foundation,
filling the trench with the appropriate amount of finished product, and then refilling the trench with
treated soil.
Many houses are pre-treated for subterranean termites with the same or similar products to those
used for post construction treatments. These treatments are effective against the target which is
subterranean termites, but have little to no effect on other types. Subterranean termites can be
controlled through the pre-treatments because it involves treating the ground which is where they live
and enter the structure. Drywood termites however infest houses with no connection to the ground.
Therefore, pre-treatments for them are done by the wood directly.
2. Part 2 Treatment Specifications
When Methyl Bromide fumigants were pulled from the market due to their tendency to damage the
ozone layer, and other flaws in regards to use and design, Vikane (Sulfuryl Fluoride) gas became the
new go-to product. Methyl Bromide has several disadvantages including large amounts of preparation
that are required before treatment, the damage it can do to susceptible items left within the structure,
and complications that arise from its liquid formulation including that it may in some cases not
penetrate pupal cases. Vikane gas and the generics containing sulfuryl fluoride are now used as the
primary control method for drywood termites. Vikane gas is moved through the structure and forced
into equilibrium by fans placed throughout.
An important factor in structural fumigation is the half-loss time. The half loss time is the time it takes
for the dosage of gas to be cut in half naturally or by some type of leakage. Most tarped structures
have some sort of leak allowing for the gradual loss of gas. Once the half-loss time is determined the
initial dose can be decided, the period of exposure set, and the decision made as to products being
reintroduced into the structure further in the process.
Vikane gas has many advantages over other gases, and other treatment methods. Vikane does not
harm the ozone layer, and breaks down quickly in ultraviolet light. Vikane is considered to be a
complete structure treatment as opposed to local treatments which only control termites in single,
predetermined areas. A few disadvantages include the necessity for vacating the structure, plant
death, and the work involved with bagging and un-bagging food items. Chloropicrin is used as a
warning agent and to prevent unwanted guests but it also burns plants. Likewise, food items must be
bagged due to labeling restrictions.
There are several options for post construction foundation treatments. Products such as Termidor,
Premise, Altriset, Talstar and others are among them. They can have specific uses, but a few things
are of note about these products. Premise and Termidor have different modes of action, but are used
about the same. Premise is systemic in plants near the treatment area however, and Termidor is not.
This means that in some cases Termidor may be the preferred method. Altriset is designed for the
chemically sensitive because it's mode of action is unique in the way it removes calcium from within
insect's muscles. Talstar, Maxxthor, Upstar Gold, Masterline Bifenthrin and other Talstar generics are
all repellent to termites and leave a barrier that in many cases won't kill subterranean termites, but
instead will force them into other areas. Termidor SC is a suspension concentrate that forms a
suspension when mixed with water. It can be used for both subterranean and drywood termites
respectively. Termidor SC can be tank mixed, but should not be mixed with other products or their
residues. In a vehicle mounted spray tank it can be applied in its diluted form for a subterranean
termite foundation treatment at a rate of 4 gallons per 10 linear feet. This should be appropriate for
almost every case, but there are cases where the soil may be tough or other issues of concern may
exist that allow the use of Termidor at a different rate. The concentrate should be 3.2 ounces per 10
feet, regardless of water used. Another solution in cases where using less water is appropriate
technicians can use Termidor HE. Termidor HE is applied at a rate of 2 gallons per 10 linear feet
when used normally.
3. Figure 1: A basic example of where a subterranean termite barrier is applied on the exterior of a
structure.
Many of the subterranean termite products can be used for drywood termite local treatments. These
products are used as a finished solution to inject into termite galleries and kills entire colonies. For
those that have little experience or are unsure of the gallery locations, drilling in a "w" pattern into the
long side of the wood gives a greater chance of success. For those with more experience and cases
where galleries are more obvious, less holes and less of a pattern may be acceptable. Some
drywood termite products come in an "RTU" or "Ready to Use" form. The more common products are
aerosols and canned pressurized products like Premise Foam, Termidor, CY-Kick CS and Pro Citra
DL. Those injecting should be careful of injected product escaping through kick out holes, and other
holes that may have been made by the technician.
Figure 2. An example of a wood piece with holes
drilled in a “w” pattern for injecting.
Borates are mineral based products that work by killing the protozoa within an insect’s digestive tract
once it is ingested. In the case of termites, it is applied to wood either topically or injected. It
penetrates the cellular structure of wood making the wood harmful to any insect that would feed on it.
It is not harmful to non-wood destroying pests when used this way. In a dry formulation however, it
can be if handled improperly, or used for that purpose. Boron can be used as a local treatment for
drywood termites or can be used as a preventative treatment for all kinds of termites. Areas such as
attics and crawl spaces are the most viable treatment areas since exposed wood can be drilled and
injected and then all of the surrounding wood can be broadcast sprayed. Wall voids and other closed
areas can be treated with an expanding boron foam that is applied using special foam machines.
These foam machines, or foamers as some people refer to them, have a tank in which boron is added
to an expanding foam adjuvant that forces the product from the nozzle with the consistency of
shaving cream. Boron can also be applied in its finished solution to newly built houses while they are
in the framing stage. In this stage, while most of the wood is exposed, a treatment can be applied for
the sake of leaving a long term residual. These treatments are generally warrantied longer, and when
combined with a subterranean termite pre-treatment of the soil will vaccinate a house against termites
for several years.
Part 3. Measuring a house for fumigation
Because fumigations are done in such a complex and complete process there is very little room for
error. Pricing and pesticide dosage have the cubit footage included in their determination. Other
factors may include roof type, difficulty of tarp installation, plant locations, and many other things.
Cubic footage is a very basic math formulation of length by width by height. As a house is drawn on
paper it may be easier to divide it into several squares. Each squares cubic footage is then added
together to get the total cubic footage. The height may not be equal throughout therefore; an average
roof height is taken to make the math work.
4. The simple equation is as follows:
The basic formula to calculate cubic feet is length x width x height.
Houses with pitched roofs will have varying roof heights therefore, an
average roof height must be calculated. To do this combine the height
from the lowest point on the structure up to the pitch, with the lowest point
up to the eave and divide by two. As noted in the diagram, you can
alternately take the distance of x, divide by 2, then add to the distance
from lowest point to half of x. Either way you should get the same answer.
As houses get more complicated they may need to be divided into
multiple sections with each measured individually.
An example of an inspection graph for the house separated into multiple
sections.
5. Length x width =area
(40’ x 40’ ) = 1,600 square feet
Area x average height = cubic feet
(1,600 square feet x 14 =22,400 cubic feet)
14’ average
40 ‘
40’
6
8
11
½ the height of from the
eave edge to the peak is
the average. (½ of 6 =3)
3 + 8 gives you an
average height of 11
Height from eave edge to peak is 6 feet 3
12
Cubic Feet
Length X Width X Height = Cubic feet of the box
Length x width x height = ÷2 = cubic feet of a triangle
4 ft
6. Part 4. Foundation Types.
There are several foundation types common in houses and an understanding of those foundation
types can be the difference between a successful and unsuccessful treatment. A raised foundation is
common in many areas, and in many parts of California raised foundation types can be found. Raised
foundations exist on those houses with subareas and basements. Inside of a crawlspace the most
reasonable treatment is the trench and treat method as mentioned before. One common style of
basement design is referred to as a California basement. California basements exist when a house
has a basement in part of it, and a crawl space in another. In these cases, horizontal drilling may be
necessary through the block foundation that separates the California basement from the crawl space.
This means that you must drill sideways through, or sometimes into the block to apply the treatment
into the proper area.
There are 3 common types of slab foundations found in houses that include, monolithic, floating, and
supported. The names are somewhat descriptive of their design, and each type has its own purpose.
The most common slab type found with regards to slab houses in California is the supported slab. It is
poured in 2 parts with the main portion resting above the footing. Floating slabs are similar but tend to
rest adjacent to the footing and are therefore not "supported." Monolithic slabs are all poured as one
piece that has no joints for expansion. Monolithic slabs are not common in California because they
tend to crack with the shifting and movement of the earth that is common in the earthquake prone
state. Subterranean termites make their way up through cracks in slabs, and around expansion joints
where floating and supported slabs are pieced together. Treatments done near expansion joints and
cracks can often result in pressurized products pushing their way through these joints, and cracks.
This does not denote treatment failure, but may actually be a sign of the opposite. Crawl space
treatments are a little different since the soil near the foundation is usually exposed. Treatments are
done to the inside foundation, the outside foundation or both depending on the circumstances.
A diagram depicting a supported slab with the expansion joints
And points of subterranean termite ingress into the structure highlighted.
A diagram depicting a floating slab with the expansion joints and points of subterranean termite
ingress into the structure noted.
A diagram depicting a monolithic slab with the ingress points noted
