Great question—and honestly, the answer depends on the bench. I’ve put together more than a dozen outdoor benches over the years, and only one arrived fully assembled. Most outdoor benches come in a flat or partial kit. You’ll typically need to attach the legs, armrests, or back supports using the included hardware, and yes, a printed manual is almost always in the box.
Some premium brands ship the seat section pre-built, so you only have to bolt on the legs. A few local retailers offer white-glove delivery or free assembly, especially for heavy teak or aluminum benches. But if you're ordering online from a big-box store, expect some DIY time.
The tools you'll need are basic: a hex key set, a Phillips screwdriver, and an adjustable wrench. Many benches include the hex key, but it’s usually small and uncomfortable—so I use my own. A rubber mallet helps seat wooden slats without denting them. If the bench has a powder-coated metal frame, keep the parts on cardboard to avoid chips.
My advice: before you start, check the parts list, sort the bolts by size, and don’t fully tighten everything until the frame is squared up. With two people, most benches take 20 to 45 minutes. If you hate assembly, look for listings that say 'fully assembled,' 'no tools required,' or 'white-glove delivery.' Otherwise, plan on a little assembly, keep the manual nearby, and you’ll be fine.