Yes, benches can absolutely be bolted down to wooden decking, and it's a highly recommended practice for safety and stability, especially in areas prone to high winds or on elevated decks. The key is using the correct hardware and technique to avoid damaging the deck structure.
For a secure installation, use corrosion-resistant lag screws or bolts, such as galvanized or stainless steel. First, position the bench where you want it. Pre-drill pilot holes through the bench's mounting points and into the deck boards. Crucially, you must ensure you are drilling into the solid deck joists underneath the deck boards, not just the boards themselves. Fastening only into the deck boards will not provide sufficient strength. Use a washer with each lag screw to distribute the load and prevent the wood from splitting. Tighten the bolts firmly, but avoid over-tightening which can crush the wood fibers.
Consider using removable options like deck anchor kits if you want the flexibility to move the bench later. Always check for hidden utilities like wiring or plumbing beneath the deck before drilling. Properly bolting your bench down will prevent tipping, enhance safety, and give you peace of mind for years of outdoor enjoyment.