That's an excellent and very practical question! The good news is, in most cases, yes, repairing a broken slat on an outdoor bench is a straightforward process. The ease of repair primarily depends on the bench's construction and material.
For traditional wooden benches with individual slats, repair is usually simple. If a slat cracks or breaks, you can often remove the fasteners (screws or bolts) holding it, take out the damaged piece, and replace it with a new one. Many manufacturers sell replacement slats for their models. If not, a piece of pressure-treated lumber or durable hardwood like teak or ipe, cut to size and pre-drilled, makes a perfect substitute. Sand and finish it to match, and your bench is as good as new.
Benches with slats that are part of a continuous, curved backrest or a more complex welded frame can be trickier. Here, repair might involve welding or specialized fabrication. However, even then, a skilled DIYer or a local metalworker can often craft and weld in a replacement section.
The key to an easy repair is proactive care. Regularly tightening fasteners and applying a protective sealant to wood can prevent many issues. If a slat does break, don't worry. Assess the damage, identify the material and attachment method, and source a matching replacement. With basic tools and a little time, you can typically restore your bench's strength and beauty, avoiding the cost of a full replacement and enjoying your outdoor furniture for many more seasons.