Drag an orange dot to resize; a dashed line shows when it snaps to a common size. Click a dot, then use the arrow keys to nudge 1/8″ (hold Shift for 1″). Every size can also be typed in the panel.
Checks
- The seat slats passes the sag check.
- The front rail passes the sag check.
- The back slats passes the sag check.
- Chairs with backs are a draft until a test build is published; build the joints exactly as shown.
- Cedar: use stainless screws. Plain steel reacts with cedar and leaves black streaks around every screw.
- Cushions to buy: 3 deep-seat sets, each a 24″ × 24″ × 5″ seat cushion and a back cushion about 24″ wide and 18–20″ tall. The seat well is 72 1/2″ wide and 29 1/2″ deep from the back slats to the front edge.
- Tie the cushions to the slats with their ties, or use non-slip pads. Outdoor cushions blow off in wind.
Shopping list
| Qty | Item | Est. |
|---|---|---|
| 2 | 4×4 cedar post, 8′ (board) | $51.20 |
| 2 | 2×6 cedar, 12′ (board) | $57.60 |
| 2 | 2×2 cedar, 8′ (board) | $14.40 |
| 4 | 2×4 cedar, 10′ (board) | $64.00 |
| 3 | 5/4×6 cedar deck board, 8′ (board) | $50.40 |
| 2 | 1×6 cedar board, 6′ (board) | $18.00 |
| 1 | 2 1/2″ exterior-coated pocket-hole screws (box of 100) | $11.00 |
| 1 | #10 × 3″ stainless steel deck screws (box of 100) | $22.00 |
| 1 | #10 × 2 1/2″ stainless steel deck screws (box of 100) | $19.00 |
| 1 | #8 × 1 5/8″ stainless steel deck screws (box of 100) | $13.00 |
| 1 | Waterproof wood glue (Type I, e.g. Titebond III) (bottle) | $10.00 |
| 1 | Screw-on nylon furniture glides, outdoor (pack of 8) | $8.00 |
| 3 | Outdoor deep-seat cushion set: 24″ × 24″ seat + matching back cushion (set) | $285.00 |
| 3 | Exterior penetrating oil or semi-transparent stain (quart) | $72.00 |
About $696 · rough estimates, check the store
Parts
| Part | Qty | Length | Width | Material | |
|---|---|---|---|---|---|
| A | Back post | 4 | 30 1/2″ | 3 1/2″ | 4×4 cedar post |
| B | Front arm post | 2 | 22″ | 3 1/2″ | 4×4 cedar post |
| C | Middle front leg Stops under the ledger. | 1 | 10 1/2″ | 3 1/2″ | 4×4 cedar post |
| D | Front rail | 1 | 72 1/2″ | 5 1/2″ | 2×6 cedar |
| E | Back rail | 1 | 75 1/2″ | 5 1/2″ | 2×6 cedar |
| F | Side rail | 2 | 27″ | 5 1/2″ | 2×6 cedar |
| G | Ledger | 2 | 72 1/2″ | 1 1/2″ | 2×2 cedar |
| H | Seat slat | 16 | 27 1/2″ | 3 1/2″ | 2×4 cedar |
| I | Back slat | 3 | 79 1/2″ | 5 1/2″ | 5/4×6 cedar deck board |
| J | Arm side slat | 4 | 34″ | 5 1/2″ | 1×6 cedar board |
| K | Arm top Round the front corners and ease every edge. | 2 | 30 1/2″ | 5 1/2″ | 2×6 cedar |
Cut list
4×4 cedar post, 96″ → A 30 1/2″ · A 30 1/2″ · A 30 1/2″
4×4 cedar post, 96″ → A 30 1/2″ · B 22″ · B 22″ · C 10 1/2″
2×6 cedar, 144″ → E 75 1/2″ · K 30 1/2″ · K 30 1/2″
2×6 cedar, 144″ → D 72 1/2″ · F 27″ · F 27″
2 × 2×2 cedar, 96″ → G 72 1/2″ each
4 × 2×4 cedar, 120″ → H 27 1/2″ · H 27 1/2″ · H 27 1/2″ · H 27 1/2″ each
3 × 5/4×6 cedar deck board, 96″ → I 79 1/2″ each
2 × 1×6 cedar board, 72″ → J 34″ · J 34″ each
Kerf 1/8″ included. Every cut runs edge to edge.
Steps
- Tape measure
- Speed square
- Pencil
- Drill/driver
- Clamps
- Safety glasses
- Hearing protection
- Dust mask
- Circular saw or miter saw
- Miter saw, or circular saw in two passes, for 4×4 posts
- Pocket-hole jig
- Clamps, 2 at least 36″
- Jigsaw (arm corners)
- Sander, 120 and 180 grit
1Before you start
Read every step once, start to finish, before you buy or cut anything. Each step names the parts it uses by letter; the parts list gives their sizes.
Set up somewhere flat with good light. A pair of sawhorses with a sheet of plywood on top makes a fine work table.
Wear safety glasses whenever a tool is running, hearing protection for saws, and a dust mask for sanding and for cutting treated wood or sheet goods. Tie back long hair and loose sleeves. Keep children and pets out of the work area.
- Tip At the store, pick straight boards: hold each one up to your eye and look down its length. Skip boards that bow, twist or have big knots near the ends.
- Tip Measure twice, cut once. Most mistakes are a misread tape, not a bad cut.
2Cut and label the parts
Cut every part on the cut list. Cut the longest parts first: if one goes wrong, it can still become a shorter part.
To mark a cut, hook your tape on the end of the board, make a small V with its point exactly at the measurement, and draw a square line through the point with a speed square. Put an X on the waste side.
Cut on the waste side of the line, so the blade's kerf (about 1/8″) comes out of the scrap, not your part.
Write each part's letter in pencil on a face that won't show, and stack the parts by letter.
Sand the faces before assembly while they're flat and easy to reach: 120 grit, then 180.
✓ Lay the parts out and count them against the parts list. Measure a few: if one is off by more than 1/16″, recut it now.
STOP. Let the saw reach full speed before it touches the wood, keep both hands clear of the blade's path, and never reach under a board you're cutting. Support long boards on both sides of the cut so the blade doesn't pinch.3Build the front frame
Drill 3 pocket holes in each end of the front rail (D) on its inside face, jig set for 1 1/2″ stock.
Lay the left front arm post and the right front arm post on the floor, 72 1/2″ apart. Glue and screw the rail between them with its top 13 1/2″ above the post bottoms and its front face flush with the posts.
Stand the middle front leg (C) behind the rail, evenly spaced, bottoms level with the other legs. Drive 2 3″ stainless screws through the rail into each.
- Tip Exterior pocket screws are coated against rust. Indoor ones streak and fail outside.
✓ The rail top is the same height at both ends, and the frame diagonals match within 1/8″.
4Build the back frame
Lay the 4 back posts (A) face up: the two end ones 79 1/2″ apart outside to outside, and the middle ones centred on the seat joints, 24″ apart.
Lay the back rail (E) across their fronts, its top 13 1/2″ above the post bottoms and 2″ in from each end. Drive 2 3″ stainless screws through the rail into every post.
✓ The posts are parallel: measure between them at the top and at the bottom, the numbers match.
5Join the frames with the side rails
Drill 3 pocket holes in each end of both side rails (F).
Stand both frames up, 27″ apart between the post faces. Fit a side rail between the front and back posts at each end, tops at 13 1/2″, set 1/2″ in from the outside faces. Glue and screw.
✓ Measure corner to corner across the top of the rails: the two diagonals match within 1/8″. Then check that the frame sits flat with no rocking.
STOP. Get a helper to hold the frames upright. A tall back frame falling over flat can crush feet.6Add the ledgers and seat slats
Screw a ledger (G) along the inside face of the front rail and another along the back rail, tops 12″ above the floor (1 1/2″ below the rail tops). 2 1/2″ stainless screws every 8″.
Lay the 16 seat slats (H) front to back on the ledgers, 1 1/8″ apart. The 1″ gaps let rain drain and air reach the cushions from below.
Drive 2 3″ stainless screws down through each slat end into the ledger.
- Tip Cut a 1″ spacer block and use it at both ends of every slat for even gaps.
✓ The slats are flush with the rail tops all the way along. A cushion laid on them should sit flat.
7Screw on the back slats
Start at the bottom: the first back slat (I) sits on the seat slats against the posts, running the full 79 1/2″.
Work up with 1/4″ gaps to the top of the posts: 3 rows. 2 2 1/2″ stainless screws into every post.
✓ The top slat is flush with the post tops and the gaps are even.
8Build the arms
On each arm end, screw 2 arm side slats (J) to the outside faces of the front and back posts, from the bottom of the rails up, 1/2″ apart. 2 1 5/8″ stainless screws into each post.
Lay the arm top (K) on the front post and the slats, centred over the post, its back end against the back slats and 1″ past the front. 2 2 1/2″ stainless screws down into the front post and 2 into the back slat edge.
✓ Press down hard on the front of each arm: it does not move.
9Finish it for outdoors
Cedar can stay bare. It weathers to silver-grey in a season or two and still resists rot. To keep the warm colour, use an exterior penetrating oil or a semi-transparent stain with UV blockers.
Outdoors, choose a finish that soaks in rather than one that forms a skin. Oil and stain fade gently and you just clean and recoat every year or two. Indoor polyurethane cracks in the sun, water gets under it, and it peels. If you want a hard clear coat anyway, use spar urethane and expect to sand and recoat it.
Brush two coats on every cut end. End grain drinks water like a straw and is where outdoor furniture rots first.
Let the finish cure fully before the cushions go on, or it can stain the fabric.
- Tip Finish the bottoms of the legs and the undersides too; they stay damp the longest.
- Tip Oily rags can catch fire on their own as they dry. Lay them flat outside to dry, or keep them in a closed metal can of water.
✓ Sprinkle a little water on a finished surface: it should bead up. When it soaks in again (usually next spring), it is time for another coat.
10Finish
Ease every sharp edge and corner with 120-grit sandpaper so nobody gets a splinter.
Sand all over with 180 grit, always along the grain (the direction the wood fibres run). Scratches across the grain show through stain.
Wipe off the dust with a barely damp rag and let it dry.
Outdoors, use an exterior finish: a penetrating deck oil or exterior stain, or primer and exterior paint. Leave cedar bare to weather silver if you like. If it holds soil for food plants, leave the inside unfinished.
Let it dry for the time on the can before using it.
- Tip Try your finish on a scrap of the same wood first: stain looks different on every board.
Conceptual layout, material estimate and assembly guide from the sizes you entered. Not engineering, not a building plan, not stamped or approved. Confirm measurements on site; follow local codes and product instructions; anchor tall pieces before use. Using this plan means you accept the Terms of Use.