Bedding???

Carefresh is the best thing I've tried for odor control, though it's very expensive for a C&C (since they're so large). If your piggies generally pee in a few specific places, the best bet is setting up some kind of litter box there that you can change daily or at least more regularly than the rest of the cage. You could also use the carefresh in that, and something else in the rest of the cage.

What are you using now? A lot of people have said that if they have newspaper under their bedding it starts to smell bad really quickly, no matter what is on top.

If you have a petstore cage, you probably need to clean it every day to 2 days. Even the largest petstore cages will get stinky fast -- the pee and poo is concentrated in a very small area. Just as you would clean a litter box nearly every day, so too do you need to clean a whole small cage nearly every day.

You could probably pay for the coroplast faster than you think with the amount of bedding you'd need to keep a petstore sized cage clean. When I was using a pet store cage the thing was just yuckie all the time and I was spending so much money in Carefresh!! I was wondering how on earth I was going to afford it because I did at least know better than to use cedar.

Now that I have my C&C built and use towels and fleece as my bedding (with carefresh in the small litterbox up top) I'm not only saving money but it does not smell. Near the end of the week you can start to smell it but it's not nearly as bad as when it was the small cage. SO much easier to clean too - not to mention how happy the pigs are in their pig castle . Everyone who has seen their cage is very impressed with it - and I must admit so am I!

Where have you looked for coroplast so far? Another name for it is Stratocore. My suggestion is to try calling university area art supply stores or any art supply store - mind you - not like hobby lobby - they won't have a clue what you're even talking about. Find a real professional art supply store and I'd be willing to bet they'd have it. I can get a whole 8 foot sheet for like 13 dollars AND they cut it for me.