Building a wooden garden bench: a simple, economical plan for two people
Building a wooden garden bench is one of the most rewarding projects for a beginner DIYer: a weekend of work, around thirty euros of materials and a piece of furniture that beautifies the terrace for years. This simple plan relies on decking boards and joists, screwed together, without special tools or expensive machinery.
The bench dimensions
A 120 cm long bench suits two people; allow 150 to 160 cm for three. A seat about 45 cm from the ground and a depth of 35 to 40 cm are comfortable. The backrest, tilted back a few degrees, is essential: aim for about 40 cm of height above the seat.
- Seat: 3 decking boards of 120 cm (section around 28 × 145 mm)
- Backrest: 2 decking boards of 120 cm
- Legs: 4 uprights in 60 × 60 mm joists or decking boards
- Reinforcement rails: 2 boards or joists of 110 cm
- Stainless steel or galvanized wood screws of 5 × 60 mm (garden wood is damp)
The right wood for outdoor use
Outdoors, wood must withstand rain, sun and fungus. Pressure-treated wood class 4 is the most common and economical solution for the parts in contact with moisture and the ground. Autoclave-treated pine decking boards or natural Douglas fir work well. If you use untreated wood, apply an outdoor wood stain or sealer, to be renewed every 1 to 2 years.
- Autoclave-treated pine class 4: economical, ideal outdoors
- Douglas fir or larch: naturally resistant, nice patina, a bit more expensive
- Wood stain or sealer: apply in 2 coats, then every 1 or 2 years
- Stainless steel or galvanized screws: bare steel rusts quickly outdoors
The assembly in seven steps
- Cut the boards to size: 3 seat boards, 2 backrest boards, 4 leg uprights
- Sand all the edges to avoid splinters
- Assemble the two legs with the rails, checking the squareness
- Screw the seat boards onto the rails leaving 3 to 5 mm between them for water drainage
- Attach the backrest uprights angled toward the rear
- Screw on the 2 backrest boards, also evenly spaced
- Stain or oil the whole thing and let it dry 24 hours before use
The tools needed
The project is done with basic tools: a saw, a drill/driver and a few measuring tools are enough. If you don't have a circular saw, hardware stores can often cut the boards to the required dimensions at the time of purchase, which simplifies the job even further.
- Circular saw or jigsaw for cutting the boards
- Drill/driver with wood bits and bits
- Tape measure, square and spirit level
- Medium-grit sandpaper for the edges
- Brush or applicator glove for the stain
Variations and customization
This bench adapts easily to your wishes and leftover wood. A longer 150 cm bench for three people does not change the technique, you just add a central leg or thicken the rails. You can also add armrests, paint the whole thing in an exterior color, or engrave the date and your initials under the seat. If you prefer a folding bench or one against a wall, take inspiration from the same screw-assembly principle, simplifying the backrest.
The mistakes to avoid
- Using untreated wood without stain: it grays, cracks and rots in a few seasons
- Screwing ordinary steel screws: they rust and leave marks on the wood
- Forgetting the gap between the boards: water stagnates and the wood rots prematurely
- Leaving the bench in direct permanent contact with damp soil
With a weekend and around thirty euros, you build a solid, comfortable and durable wooden garden bench. The most important points are the choice of treated wood and stainless steel screws, as well as a slight spacing between the boards to let water pass. You get a unique piece, made with your own hands, that will host summer evenings for many years.
To extend the life of your bench, inspect it once a year in spring: retighten any screws that have worked loose, lightly sand the areas that are graying and renew the stain or oil if necessary. A maintained bench is passed from season to season, and remains a favorite meeting spot for garden breaks.