The Problem: Narrow paths and soggy seats
Commercial garden benches are almost always too deep for a terrace house patio or balcony. At 650mm front-to-back, they force you to walk sideways past the table. Worse, mass-produced softwood benches rely on thin tenons glued into blind mortises. Once winter rain seeps into those upward-facing joints, the wood swells, crushes its own fibres, and develops a permanent side-to-side racking wobble by spring.
Our courtyard bench trims the overall depth to a trim 410mm—comfortable for an hour with a book, yet slim enough to tuck beneath a kitchen window sill. Even better, every structural intersection is an open, free-draining half-lap joint fastened from the underside so rain rolls straight off the top slats.
Timber Selection & Cut List
Buy kiln-dried C24 structural graded European Larch, Douglas Fir, or pressure-treated redwood (Use Class 3 or 4). Sight down each length at the timber yard and reject boards with heart-centre pith, which splits rapidly in July sun.
| Part Name | Qty | Dimensions (mm) | Notes & Preparation |
|---|---|---|---|
| Seat Top Slats | 4 | 45 × 95 × 1200 | Ease top arrises with 6mm router radius or 80-grit block; crown side up. |
| Long Rails (Aprons) | 2 | 45 × 95 × 1060 | Notched at both ends for leg half-laps. |
| Vertical Legs | 4 | 45 × 95 × 410 | Fit 10mm HDPE plastic glides to bottom end-grain before assembly. |
| Cross Bearers | 3 | 45 × 95 × 380 | Top edge planed at a 2-degree cant so rain sheds toward the rear slat. |
| Lower Stretcher | 1 | 45 × 70 × 1060 | Centred 120mm above patio level to prevent long-span leg splay. |
Numbered Assembly Sequence
- Acclimatise and crown-mark the slats: Look at the end-grain of your four 1200mm seat slats. Orient the growth rings like a frown (bark side up) so rainwater sheds off the crown rather than cupping into a puddle down the middle of the plank.
- Cut the leg-to-bearer half-laps: Set your circular saw depth to exactly 22.5mm (half the 45mm thickness). Make shoulder cuts 95mm down from the top of each leg, then make series of kerf cuts and pare the cheek flat with a sharp 38mm chisel.
- Seal internal joint cheeks before gluing: Coat all end-grain inside the joint areas with end-grain preservative, leaving the flat glue faces bare. Assemble the two end frames using D4 polyurethane adhesive and two 5.0×40mm A2 stainless screws per joint.
- Connect the long aprons and central bearer: Join the left and right leg frames with the two 1060mm long rails. Check diagonals with a tape measure until both figures match within 1mm, then fix the centre cross bearer to prevent seat bounce.
- Space and counter-fix the top slats: Clamp the four seat slats across the frame using 6.5mm carpenter pencils as consistent spacing gauges. Drive 5.0×80mm stainless screws up through the underside of the cross bearers into the slats so no screw heads show on top.
"Counter-fixing seat slats from underneath takes twenty extra minutes on the workbench, but saves your trousers from snagging on weathered screw heads and keeps water out of top-face pilot holes." — Maintenance Note: Hidden Fixings
Weather Exposure & Annual Upkeep
Even durable larch and Douglas fir will silver to driftwood grey within nine months of UV exposure. If you like the silvery patina, simply brush off autumn leaf litter and apply a clear water-repellent preservative every October. If you want to retain the warm honey-terracotta tone, brush on two thin coats of pigmented UV decking oil, wiping away any unabsorbed puddles after fifteen minutes with a lint-free cotton rag.
Looking to frame your new seating corner with greenery? Combine this bench with our vertical herb ladders or tuck garden cushions inside a weatherproof potting locker.