Great question—this is one of those projects where the right hardware makes all the difference. If you drive screws straight through the feet of the bench, you will get a strong connection, but you will also leave permanent holes in the deck boards. The good news is you can absolutely anchor an outdoor bench to a deck without damaging the wood if you use clamps, existing gaps, or clever weight placement.
Before you choose a method, measure the thickness of your deck boards and the width of the gaps between them. Most no-drill deck bench anchors are designed for standard 5/4 or 2x deck boards, so knowing those numbers will save you a return trip to the hardware store.
1. Use a no-drill deck bench anchor kit.
This is my favorite solution for a real mechanical hold with zero visible damage. These kits usually have a top hook or plate that slides into the gap between two deck boards, and a bottom plate that tightens underneath with a bolt. The two plates grip the board from above and below, so there is no hole in the top surface. You simply position the bench leg over the clamp, bolt the leg to the top plate, and snug everything down. If your bench has legs that sit flat on the deck, this is the closest you will get to a permanent anchor without drilling.
2. Use the gaps between deck boards to reach the joists.
If your deck boards have enough spacing, you can run stainless steel bolts or hanger bolts down through the gaps and into the joist below. The deck board itself is not drilled. To prevent the bolt from biting into the edges of the boards, slip a rubber or plastic spacer around the bolt where it passes through the gap. This works especially well when you can line up a bench leg with a joist, but you can also add a small metal or wood cross brace under the deck if needed.
3. Add hidden weight to the bench.
For a truly zero-contact option, make the bench heavy enough that it stays put. You can bolt the bench to a wide, heavy base platform or fill a bench storage box with sandbags, concrete pavers, or steel plates. This is not as strong as a mechanical anchor, so I would only rely on it in a sheltered area. In high winds or on an exposed deck, use this as a supplement to one of the methods above.
4. Attach the bench to a nearby structure.
If your bench sits against a house wall, railing, or sturdy post, you may be able to anchor it there instead of through the deck. A heavy-duty L-bracket or angle bracket can secure the bench frame to the wall or post, keeping every fastener out of the deck boards. Just make sure the supporting structure is solid enough to handle the load and the movement of people sitting down.
5. Add anti-slip pads for extra stability.
Dense rubber pads or outdoor grip tape under the bench feet will not hold the bench in a storm, but they do reduce sliding and protect the wood from scratches. I use these on almost every outdoor bench, even when I also use a no-drill anchor.
A few things I would avoid: construction adhesive or strong double-sided tape directly on the deck boards. They can rip up the finish or leave a sticky residue that collects dirt. Also avoid galvanized hardware that is not rated for treated lumber, and choose stainless steel or coated fasteners to prevent rust stains.
My overall pick is the no-drill deck bench anchor because it gives you a solid mechanical connection without putting a single hole in the top of the deck. Whichever method you choose, check the hardware after a few weeks and at the start of each season, because wood expands and contracts with temperature and moisture.