How Commercial Contracts Define Trigger Depth

4 min read · Thames Valley Snow, London, Ontario

Trigger depth is one of the most important terms in a commercial snow removal contract, and it's also one that's frequently misunderstood by business owners signing their first agreement. Getting this right avoids frustration all winter.

Trigger depth simply means the amount of accumulated snowfall that automatically triggers a service visit under your contract. A common trigger might be two or five centimetres, meaning the contractor comes out once that amount has accumulated, rather than waiting for a phone call or a fixed daily schedule.

A lower trigger depth means more frequent visits and generally higher cost, since the contractor is responding to smaller accumulations more often. A higher trigger depth means fewer visits, potentially with more snow built up before each one, which usually costs less but leaves your property less consistently clear.

The right trigger depth for your property depends on your traffic and risk tolerance. A high-traffic retail entrance benefits from a low trigger depth to stay consistently accessible, while a lower-traffic industrial yard might reasonably operate with a higher trigger depth without meaningfully increasing risk.

How Trigger Depth Is Measured

A trigger only works if both sides agree how it is measured. Snow does not fall evenly, and drifting can leave one corner of a lot deep while another is nearly bare. A good contract states that the trigger is based on accumulated snowfall, and it explains what happens during a storm that keeps going for hours.

At Thames Valley Snow, our automatic service starts at 5 cm of snowfall. Nobody has to call us. Once that depth is reached, the property is added to the route, and in long storms crews return so snow does not build up between visits.

Trigger Depth and Ice Are Different Problems

Trigger depth covers snow. It does not cover ice. Freezing rain, drizzle and overnight refreezing can make a lot dangerous with almost no accumulation at all. That is why salting and ice control should be a separate line in your contract, with its own conditions. Our seasonal salt service includes freezing rain and refreeze visits, so ice is handled even when there is no snow to plow.

Questions to Ask Before You Sign

• What exact trigger depth starts a visit, and is it written in the contract?
• What happens in long storms that go well past the trigger?
• How is ice handled when there is little or no snow?
• What proof will you get that each visit happened?
• Is the contractor insured and WSIB registered?

With us, every visit comes with a timestamped photo. We carry $2,000,000 in liability insurance, are WSIB registered and belong to the London Property Management Association (LPMA). Commercial sites are priced per site, with a quote within two business days.

Matching the Trigger to How Your Site Is Used

Think about who uses your property and when. A medical clinic or retail store with customers arriving all day needs walkways and entrances usable from opening time, so priority early-morning clearing and salt matter as much as the trigger. A warehouse with a few staff vehicles may tolerate a little more snow between visits. Talk through your opening hours and busiest areas when you request a quote, so the plan fits how the site actually works.

Frequently Asked Questions

Is a lower trigger always better?

Not always. A lower trigger means more visits and higher cost. Busy entrances may be better served by a standard trigger plus good salting.

Do I need to call when the trigger is reached?

No. Service is automatic once 5 cm has fallen.

Ready to stop worrying about the next storm? Get a free quote, or call or text (548) 888-8702. You can also read more about commercial snow removal and salting and ice control.

What's included… and what's extra

Commercial snow service is priced per site from paved area, walkway length and opening time. A typical contract includes plowing at the agreed trigger depth, clearing before opening, hand-cleared entrances, sidewalks and ramps, and a timestamped photo log of every visit.

Common extras are quoted separately so you only pay for what the site needs: salting and de-icing per event, extra sidewalk or ramp coverage, after-hours or priority service, and snow relocation when piles run out of room. See commercial snow removal or request a site quote by calling or texting (548) 888-8702.