If the coating on your tent fly or floor starts to crack and peel, you just may be able to fix it for a few bucks (as opposed to forking over a couple of hundred for a new tent). First, you'll need to clean the tent and remove any residual coating. Normally, putting your tent into the washing machine is a huge no-no, but this is the one case in which you're allowed to. The washer and dryer wreak havoc on the waterproof coatings of your tent, but since you need to strip the coatings in order to properly refurbish them, the washing machine is your best bet. Zip all the zippers and fasten all the Velcro swatches, then run it through the gentle cycle with cold water and a touch of a mild powdered soap (like Ivory).
Then, pop it in the dryer on low heat for about 5 minutes. Remove the tent and hang it until completely dry. Then scrub the floor with a vegetable brush to remove any remaining flakes.
When the tent is clean and dry, set it up and flip it onto its side. Using a polyurethane product that's designed specifically for the task (check your outdoor shop for the best options) simply follow the instructions and evenly paint the outside of the floor. Let it dry completely before packing it away.