Things You'll Need
- Permanent marker
- 30 gallon plastic storage container
- Cutting shears
- File
- Drill with 1/8 inch bit
- Activated carbon air filter sheet
- Duct tape
Instructions
Turn the storage tub upside down and draw an arching outline for an entrance that is large enough for the cat using the litter box you are covering.
Cut through the plastic with a pair of sharp cutting shears to remove the section inside the door outline.
Slide a file back and forth over the rough plastic edges to remove any barbs that may poke the cat and create a smooth door surface.
Hold the box upside down over the cat and lower it down on top of them. Watch the cat exit to make sure there is about 4 inches of clearance above the cat's back. Trim the opening with the shears and refile it smooth until you are satisfied with the door size.
Create a perforated area in the bottom section of the plastic storage tub that is about 4 inches wide and 8 inches long. Drill a series of 8-inch holes that are about half an inch apart until you have vented the 4-by-8 rectangle.
Cover the perforated section of the plastic storage box with an activated charcoal air filter sheet and tape the sheet in place with two small pieces of duct tape. As warm air rises from the litter it will be vented through the holes and filtered by the charcoal sheet.
Lower the liter box cover sown over the litter box with the opening facing the direction you want the cat to exit. Observe the box cover for the first few litter uses to make sure the door size or box location is not making it difficult for the cat to enter and exit.