How to Keep Spiders Out of Your Basement (Without Harsh Chemicals)

If you’ve flipped on the basement lights in winter and suddenly wished you hadn’t, you’re not alone. 

In Calgary and across Western Canada, basements and crawl spaces are the most common places homeowners spot spiders once the weather turns cold (followed closely by garages).

And when you see a big one skitter across the floor, the knee-jerk reaction is usually to reach for a can of spray. But blasting your basement with harsh chemicals isn’t the safest move. For one, you’re storing boxes, kids’ gear, or workout equipment there. Secondly, egg sacs are often untouched. And finally, basements have limited ventilation, which means airborne chemicals linger longer. Even products labelled “low odour” or “safe once dry” can affect indoor air quality.

So what do you do instead? 

Photo credits to unsplash.com

A Simple, Non-Toxic Basement Action Plan

You don’t need chemicals to make your basement less spider-friendly. You need a plan and consistent follow-through.

Pro Tip: Start from the outdoors.

And then…

Step 1: Reduce Moisture

Spiders follow insects, and insects follow moisture. Use a dehumidifier if the humidity stays above 50%. Fix small leaks promptly, even slow drips from pipes or foundation seepage. Improve airflow in corners, behind appliances, and around floor drains where dampness tends to linger unnoticed.

Step 2: Declutter Strategically

Clutter creates shelter. Replace cardboard boxes with sealed plastic bins and avoid storing fabric or paper directly on floors. Elevate storage on shelves or pallets and keep wall-to-floor junctions clear so spiders can’t easily build webs in undisturbed areas.

Step 3: Seal Entry Points

Inspect foundation cracks, utility penetrations, window frames, and basement vents. Seal gaps with appropriate materials to block spider access and limit insect entry. Even small openings can act as regular entry routes over time.

Step 4: Improve Basement Cleanliness

Vacuum regularly along baseboards, corners, and ceiling edges. This removes webs, egg sacs, and scent trails that encourage spiders to resettle in the same spots.

Step 5: Physical Removal When Needed

If you’re seeing recurring spider activity, large populations, or spiders in hard-to-reach areas, this is where a pest control company like Buzz Boss can help. Our outdoor-focused, low-impact approach targets the source of the problem around your home’s exterior, reducing the number of spiders (and the insects they feed on) that ever make it into your basement in the first place.

A Healthier Way to Handle Basement Spiders

Spiders don’t belong in your basements, but neither do harsh chemicals in the air your family breathes. The good news is that you can take control of the situation by addressing the conditions that invite spiders inside in the first place, rather than relying on toxic sprays. You start by covering your exteriors. 

At Buzz Boss, we take a prevention-first approach that focuses on spider control strategies that protect your home without compromising your health. We offer 3 pest control packages, each designed to keep your home’s exterior pest-free all season long. You can compare packages here. Our methods are completely safe for kids and pets.