Choosing the right fasteners is crucial for building a wooden garden bench that stays sturdy and safe for years. For most joints connecting wood to wood, such as attaching legs to the seat frame or securing back slats, I highly recommend using outdoor-rated wood screws. Look for screws labeled as corrosion-resistant, such as hot-dipped galvanized, stainless steel (304 or 316 grade), or coated deck screws. These materials withstand moisture and prevent unsightly rust stains. Their sharp points and aggressive threads provide excellent holding power without the need for pre-drilling a full pilot hole in softer woods, though a pilot hole is still good practice to prevent splitting.
For critical structural points where immense shear force is expected—like where the main legs meet the long seat support beam—galvanized lag bolts (lag screws) with washers are the superior choice. These are much heavier-duty than screws. You must pre-drill a pilot hole slightly smaller than the bolt's shaft. The washer distributes the clamping force, preventing the bolt head from pulling into the wood and ensuring a rock-solid connection that won't wobble.
Don't overlook corrosion-resistant metal brackets and braces. Angle brackets, T-braces, and corner plates add tremendous reinforcement to joints, especially for benches with complex designs or heavy expected use. Attach them using the screws or bolts recommended above.
Avoid standard interior drywall or construction screws, as they will rust quickly. Also, while nails are fast, they work loose over time as wood expands and contracts with the seasons, leading to a shaky bench. Your goal is to create rigid, permanent joints. Invest in quality fasteners from the start; they are the invisible hero ensuring your beautiful garden bench remains a reliable retreat for many seasons to come.