About Laurie Chambers and the Critterproof Composter

I’m Laurie Chambers. I live in Lund, just north of Powell River on the west coast of Canada, where black bears still live in the woods.

Here’s a picture of a composter I built out of two-inch cedar boards, with a heavy aluminum plate top. It took a bear 20 minutes to make this hole.
Next, I built a composter of three-inch thick seasoned fir, with the nail heads pointed out, to discourage scratching. But it’s a lot of nails, and it looks ugly. This is a mother bear about to have a snack from that composter.

This time she didn’t have to claw her way in, because someone forgot to properly latch the lid, so she flipped it out of the way.
I feel strongly about the way our garbage habits are hurting the planet. I also like bears. Bears that get used to seeing the composter as a feeding station can be dangerous, and for that reason, a lot of them are killed.


It was a big problem, the kind that requires a complete rethinking. This composter is made using concrete formwork, faced with stone, with recessed bolts holding the aluminum lid, front door and back vent in place. As unique as it looks, this design uses proven methods for producing compost.

It’s a bonus that it turned out to be beautiful, but it did. Apart from being critter-proof, this is more than likely the first composter ever made that’s equal on the outside to the beauty of what’s going on inside: the transformation of organic wastes into rich, life-giving compost.


Right now there are 20 of these composters in use in and around Powell River. They’ve all gone through at least one full bear season. Bears have shown interest, but once they check it out, they know they can’t get inside, and they go away. And the compost these bins produce is the best of black gold.

Here’s a video shot by Bernadette Giroux, of her family’s Critterproof Composter in action.


Inside, there’s a screen angled across the bottom of the bin that allows air from the ventilation hole at the bottom of the back of the bin to move up through the compost and out through a vent at the top. Because hot air rises, the heat of the compost constantly flows out through the top vent and pulls cooler air in from the bottom. You don’t need to turn it, but it certainly helps to punch holes in it with a pointed stick or preferably a wingdigger. You do need to treat it like any other composter, and layer in an appropriate mix of kitchen wastes and carbon sources, such as dry leaves, sawdust or shredded newspapers, and soil with lots of life, not sand, to control odors and capture valuable nitrates. Core samples taken on the bins already in use are showing great results: rich, fully digested compost. Food does not decompose as quickly as in a rotating bin, but it has more organic life in it. Like slow food, slow composting has a lot to recommend it.

About Eve Johson and Alan James

Eve Johnson is a fan of both compost and bears. Drawing on 20 years of newspaper reporting, she wrote the directions for building the composter and handles the technical end of websites and sales.

Alan James is an architect and photographer. He took the photos to document the process and made the working drawings for building the composter.