How hard is assembly on heavy-duty garage shelving?

Boltless rivet-style units (the most common heavy-duty design) typically take 20–45 minutes per unit for one person and require only a rubber mallet. Wire shelving with snap-on collars is faster. Reviewers consistently flag that the larger 70-inch-plus units are easier with two people, mostly because of the awkward upright lengths rather than the part count.