A lot of us who use shredded cardboard run it through a paper shredder. A shredder that can handle at least 8 sheets can handle most cardboard if you rip it done to about 4 inches wide first. Heavier cardboard needs to have the layers separated as well.

I buy peat by the bale as I use this as a filler mix on my potted plants. This is the main filler I use for bedding. I soak this in bucket pail and then wring it out by hand to where its lightly dripping. To this I will mix in a good amount of shredded newsprint, small chunks of cardboard, maybe some coffee grounds, even a handful or two of black kow. On occasion but not every day I will throw in a coffee filter with used grounds. I used to use coir in the bins but the one I was using would leave long straw like strands on harvest day so I quit using it for my bins but still use it for my potting mixes. Thats my two cents, same method I use every new bedding fill. Also the cardboard gets soaked good before use.

I ended up trying to shred a some cardboard at the office, but pretty much gave up. The machine was totally up to it, once you got the cardboard in, but the angle of the feed made it almost impossible to get each piece started (and I was worried the secretary would see what I was up to and yell at me...).

I ended up taking some of the office paper and shredding some newspapers. I added this dry to the rubbermaid container in the hopes of pulling out some of the excess moisture in that bin.

Best solution: Buy your own Strip Shredder (they're cheap enough) and work at home. I have a 12-sheet (2 years on and going strong).

Shaul (aka shaul_gw)