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Last Updated: , Created: Thursday, November 29th, 2001

Protecting your house from termites.

Termites and carpenter ants are the two most destructive insects for homes constructed with wood. Termites eat the wood in a home while carpenter ants simply burrow living quarters in the structure.   Both remain connected to colonies outside the house and it is this necessary traveling between your home and the surrounding environment that allows us to control them.  Although people often confuse termites and carpenter ants, they are not even really cousins.  There are several visible differences but the easiest to spot is that Ants have segmented bodies, the termites have a long continuous body. To help you identify Carpenter Ants, click here.

Technically, termites are limited to tropical areas, but some species are native to British Colombia. Although nowhere near as prevalent in cold Canada as in the balmy southern US, termite tunnels do exist in Canadian houses. They tend to be regionally confined and exterminators in your area can tell you if they are a potential problem. In Toronto it is most interesting that the slow annual spread of termites from the docks up through the neighborhood called “The Beaches” and beyond can be traced back to a shipment of crates from England during the Second World War. 

It is easy to tell termites from ants, in that ants have an hourglass like figure joined in the centre by a very thin stem. Termites have a rather straight oblong body of equal thickness and are about half an inch long. They only have wings when they swarm (fly to a new home all together) in the spring. For homeowners and contractors alike, the interesting part of their life style is that they shun daylight and fresh air. Also, they must return to the soil regularly to survive and connect with the queen colony, which is usually outdoors. That means that they need pathways in and out of their food source, your wooden house.

As termites do not have hard protective shells like ants do, they need to be able to bore directly from the ground into the wood, or they need a protected pathway. If you permit no wooden part of the house to touch the soil and no pile of fire wood to touch the siding, that eliminates the easiest pathways, although they could crawl up through the hollow cores of concrete blocks, or even up a concrete foundation crack. When they can’t get direct access to the wood, they build earthen tunnels that protect them from light and the drying effect of air. If you have taken care to provide no hidden pathways, then the tunnels become the visible sign of their presence. If you do find the tunnels, keep them broken and the ants will dry up and die.


Termite barriers

We can, with difficulty, kill termites already established in your house walls, and we can build physical and chemical barriers to keep new ones from coming back in from outdoor colonies, but the only real eradication of residential termites is to work on a neighborhood wide basis that kills all the outdoor colonies.  Few municipalities want to finance that so they leave it as a perpetual individual homeowner problem.

Present termite control methods are not aimed at killing termites, but at creating a barrier around the house to prevent them from commuting from their habitats in the soil outside the house to your wooden structure where they feed.

They are an insect without a shell so they need protection to keep their body moisture, hence they always burrow tunnels from the soil to the house, or build visible tunnels over material they cannot burrow through like the concrete wall.

The barrier, or insect moat, is created around your foundation by drilling holes into the ground every few inches and injecting insecticides into the ground, both on the outside and the inside of the foundation wall. Here we were working with the guys from PCO Orkin pest control in Toronto.

This does not eliminate termites in the neighbourhood, not even in your yard, so you will have to maintain this protective barrier every few years. Termites cannot be eradicated on a house by house basis as they will continue to live in the yard, or next door.

Termite barriers installed during new construction

In the southern US where it is taken for granted that the soil around your house is loaded with termites, the building codes require that there be a visible break between the soil and the rest of the house. Basement insulation is not allowed up the outside of the house continuously from the footings up as we do commonly here. Interior basement insulation must leave a two inch gap before the sill plate, to be able to spot the tunnels.

So in Canada, if you have termites, and you apply standard construction practices for termite control, you guarantee yourself a condensation problem and a cold floor. One innovative solution during new construction is to install a cap flashing right into the wet concrete of a slab-on-grade or a poured foundation that will receive below grade foam insulation panels. More panels are installed right on top of the flashing, but the lip of the flashing will force any termites into building their tunnels over the flashing, exposing them to detection.

An interesting note about pressure treated wood and termites. The chemicals in the wood do not kill the termites, it is too diluted for that. Rather it makes the wood non-nutritive, so they simply taste it and go elsewhere.

Keywords: Damage, Insects, Termites, Pests, Rot

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