Spider & Crawling Insect Control, Collingwood

This is the group people call about when they cannot name what they saw. Spiders, house centipedes, earwigs, silverfish, sowbugs and ground beetles are treated the same way and, more importantly, they are caused the same way — a damp margin around the building and somewhere dark to sit inside it.

Escarpment properties get more of it, and here is why

A house built into the slope below the escarpment has rock, leaf litter and shade against at least one wall, and drainage that arrives from uphill. That margin holds moisture through the summer and it is continuous harbourage. Properties on the sand at Wasaga Beach have almost the opposite profile and see far less of this, which is a useful diagnostic in itself: if you have moved from one to the other and noticed a change, this is why.

What the treatment is, and what it is not

An exterior residual band around the foundation, into the weep holes, under the sill and around window and door frames, plus targeted interior work in the basement and any crawl space. It knocks down what is present and stops the season's entry. What it is not is permanent: it degrades in sunlight and rain, and on a shaded damp wall it is a single-season measure.

Spider and centipede control in Collingwood basements

House centipedes are the one that generates the alarmed evening phone call, and they are worth understanding rather than only treating: they eat the other things in your basement. A house with a centipede population has a food supply, so treating the centipede alone is treating the symptom. The silverfish and sowbugs they are living on come from the same damp.

Are any Ontario spiders dangerous?

Practically, no. There is no brown recluse population in Ontario and the black widow is confined to a few pockets far from here, so the spiders in a Collingwood basement are cellar spiders, funnel weavers and their relatives. That matters because it changes the right answer: this is a nuisance and comfort job, and nobody needs to treat a whole house for it.

The four fixes that beat any treatment

• Pull the mulch, leaf litter and stacked wood back 300 mm from the foundation. This is the single biggest one.
• Fix the downpipe that discharges beside the wall instead of away from it.
• Dehumidify the basement to under 50% relative humidity. Silverfish and sowbugs cannot hold a population below that.
• Fit or replace door sweeps. Most of what walks in, walks in under a door.