Something that's shoddily built using the cheapest possible materials is jerry-rigged.
If the climbing structure you build for your cat is held together with duct tape and staples instead of screws and nails, you can describe it as jerry-rigged (and you can also expect it to collapse within a week). This term comes from the nautical jury-rigged, derived from the Middle English jory, "improvised," and rig, or "sail." The jerry version dates from the 19th century and a Liverpool slang meaning of the name Jerry, "defective."