48″ long deck box plans

Parts

Cut list

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
• Table saw or track saw for ripping
• Clamps, 2 at least 24″
• Spacers: 1/8″ hardboard strips
• Sander, 120 and 180 grit

Underlined words have a short explanation: hover or tap them. All of them are on the glossary page.

1. 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.

2. 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.

3. 3Build the front and back walls

   Lay two corner posts (A) on a flat surface, 43 1/2″ apart inside, their bottoms on a straight line. They stand 3/4″ below the slats as feet, so water drains out and the slats never sit in a puddle.

   Lay the bottom slat (B) across them, 3/4″ past each post (the end slats tuck into that space later), its bottom edge 3/4″ above the post bottoms. Predrill and drive 2 1 1/4″ stainless screws into each post.

   Work up with 1/8″ gaps (a strip of 1/8″ hardboard is a good spacer) to the post tops: 4 rows, the top one ripped to 5 3/8″. Build the second wall the same way.

   • Tip The small gaps let the boards swell in wet weather without pushing the box apart.
   • Tip 1 1/4″ screws through a 3/4″ slat into a 1 1/2″ post will not poke out the inside.

   ✓ Measure each wall corner to corner both ways: the diagonals match within 1/16″, so the box will be square.

4. 4Join the walls with the end slats

   Stand the two walls up, posts inside, 24″ apart outside to outside. A helper or a clamp across the top keeps them upright.

   Fit the end slats (D) between the front and back slats, lined up with their rows, and screw them into the posts: 2 1 1/4″ stainless screws at each end.

   ✓ The box sits flat on its four post feet, and the diagonals across the top match within 1/8″.

5. 5Fit the floor

   Screw a floor cleat (F) to the inside of the front wall and another to the back wall, between the posts, bottoms flush with the bottom slats: 1 5/8″ stainless screws every 8″ through the cleat into the slats.

   Lay the 11 floor slats (G) across the cleats, 1/2″ apart, and screw each end down: 1 1 5/8″ stainless screws.

   The gaps are the drainage: any water that blows in runs straight through. Do not close them up.

   ✓ Pour a cup of water on the floor: it drains out underneath within seconds.

6. 6Build the lid

   Lay the lid boards (H) and the two end boards (I) face down on a flat floor, 1/16″ apart, ends lined up. The lid is 50″ × 26″: 1″ bigger than the box all round so rain drips clear of the walls.

   Lay the two battens (J) across them, 2″ in from the front and back edges and centred end to end, so they drop just inside the walls when the lid shuts.

   Predrill and drive 2 1 1/4″ stainless screws through the battens into every board.

   • Tip Lay the boards with the growth rings arching up on the top face, so they shed water as they cup.

   ✓ Set the lid on the box: the battens drop inside the walls with a little play and the lid sits flat.

7. 7Hang the lid

   Set the lid in place, overhanging evenly. Screw 2 stainless strap hinges across the back: the long strap on the lid, the other leaf on the back wall's top slat, one 6″ from each end.

   Use the stainless screws that come with the hinges. Open and close the lid a few times; it should not bind on the walls.

   ✓ The lid swings open past straight up and closes square on the walls, overhanging the same all round.

8. 8Fit the gas struts

   The lid weighs about 20 lb. Each strut needs to push about 24 lb (110 N); buy a matched pair near that rating.

   Mount one strut at each end, inside the box: the body bracket on an end wall post, the rod bracket under the lid about 6″ from the hinge line. Follow the kit's chart for the exact spots, rod end up.

   Open the lid fully, then let go at half-open: it should stay put or rise slowly. If it slams shut, the struts are too weak; if it will not close, too strong.

   ✓ The lid never drops shut on its own from any angle.

   STOP. A lid that falls can pinch fingers. Do not use the box until the lid support holds it open; check it again every spring.

9. 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.

   Leave the inside unfinished or oil it lightly; a film finish inside traps moisture against the wood.

   • 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.

10. 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.