Workshop
Start a discussion

The Bunnings Workshop community can help with your home improvement projects.

How to build a planter box with bench seats

Adam_W
Valued Contributor

Difficulty: Intermediate

Garden in comfort with this very achievable planter box with integrated seating. There’s no digging or concreting necessary for the build  all you need is an area of level ground.

Video Tutorial

Steps

Step 1

Mark and cut all sleepers into 1200mm lengths. Cut four lengths in half again to make eight 600mm lengths.

 

Step 1 - Measure mark and cut all sleepers.jpg

Step 2

Take two of the 600mm sections, align their edges and ends and butt join with 100mm screws, one screw towards each end and one in the middle.  

 

Repeat to make four corners.

 

Step 2 - Create corners from 600mm lengths.jpg

Step 3

Position one corner block and pay close attention to its configuration. You will notice that the internal faces are different lengths – 150mm and 200mm. Position a 1.2m sleeper section square into the corner with its face flat against the 150mm side. Lightly clamp and feel underneath to check the sleeper is aligned with the bottom edge of the corner block before screwing in place with at least two 100mm screws. Repeat for the far end of the sleeper and then to make the second end section.

 

Step 3 - Position sleeper in corner align and secure.jpg

Step 4

Stand both end sections up. Position a 1.2m sleeper section into the corner against the long side of the corner block, align and screw in place with one 100mm screw. Use your square to check it is correctly aligned and secure with second screw. Repeat for the far end and then the other side. 

 

Once all the sections are joined use your square to check inside corners and adjust if required. The corner blocks should naturally keep the corners square.

 

Step 4.1 Add sleeper section to long face of corner and secure.jpg  Step 4.2 Check corners with square.jpg

Step 5

Use your short level to check that the sides are suitably level and make any required adjustments. Add the remaining side boards in the same sequence, short face followed by long face, until all are secured.

 

Step 5 Add remaining side boards.jpg

Step 6

Measure the length of the face between the corner posts where you plan to add seats. From 1.2m sleeper lengths cut two pieces to size for each seat.

 

Step 6 Measure between corner posts on sides that will have seats.jpg

Step 7

From the 90mm x 45mm treated Pine cut two 350mm lengths for each seat. On one cut end measure and mark at half (45mm) for 45 degrees and saw off. These are your seat rails. 

 

On a sleeper you cut for the seat mark 50mm in from the end and position and clamp a seat-rail section with its end flush with the back of the sleeper and on the inside of the marked line.

 

Step 7.1 Cut 90 x 45 for seat rails.jpg  Step 7.2 Mark 50mm in from edge of cut sleeper and position rail.jpg

Step 8

Carefully roll the clamped pieces over and secure them using two 100mm screws through the sleeper face. Position the second seat board, clamp and screw down and then repeat for the rail on the far side and to create any other seats.

 

Step 8 Roll over and secure with 100mm screws.jpg

Step 9

Measure between the seat rails and cut 90mm x 45mm treated Pine to suit. This is your seat support. You may wish to cut the piece 10mm short to give you some wiggle room during installation of the seats.  

 
Mark the centre of the support rail. Determine the correct seat height (most seats are 400mm to 450mm high) and then mark the centre between the corner posts on the face of your bed at this height. We used the top of the second sleeper to align our rail as this was exactly 400mm. 

 

Align the centre mark on the rail with the centre mark on the bed and use at least three 100mm screws to secure the rail to the bed face and then add another three 100mm screws from inside the bed.

 

Step 9.1 Measure between seat rails.jpg  Step 9.2 Attach rail to bed face.jpg

Step 10

On a 1.2m length of sleeper use the 45-degree side of your square to mark a series of triangles, two per seat. Then cut these apart. 

 

Position the triangle support at the rear of the seat, flush with the seat edge. Use two 100mm screws to attach to the seat rail. Repeat for other sides and seats.

 

Step 10.1 Use square at 45 to mark a series of triangles.jpg  Step 10.2 Attach triangle support bracket to seat.jpg

Step 11

Slide the assembled seat into place between the corner posts and on top of the rail. Screw through triangle supports into corner posts with 150mm screws; through from inside the bed wall horizontally into the seat panels with three 150mm screws; and at a slight angle down through the top of the seat at the rear into the support rail with three 100mm screws.

 

Step 11 Position seats and screw to corner posts.jpg

Step 12

Inside the bed measure the length of the short sides and cut two pieces of 90mm x 45mm treated Pine for support rails. Position with their top edge 350mm down from the top of the bed and use at least five 100mm screws to fix off. Add at least another three 100mm screws through from the outside.

 

Step 12 Add support rails to short sides of inside of bed.jpg

Step 13

Place your 1200mm level on top of the rails and mark centre at both ends. You don’t need to measure as the level vial should be in the centre – just mark there. 

 

Measure and cut a sleeper to fit between the marked points and then, using the level on the rails as guide, position the sleeper and secure through the bed wall with 150mm screws. This will work as a central support. Add a centre prop by positioning a sleeper offcut in the middle of this sleeper, resting on the ground, and screw it to the sleeper with 100mm screws.

 

Step 13.1 Mark centre of bed between rails.jpg  Step 13.2 Fit centre support.jpg

Step 14

Lay 1200m sleepers on top of the rails and centre support. Once they are all in place, adjust to be evenly spaced. 

 

Secure sleepers in base of bed with 75mm screws, two at each end and one into the centre support.

 

Step 14.1 Add sleepers to rails.jpg  Step 14.2 Screw sleepers down with 75mm screws.jpg

Step 15

Cut drainage or filter fabric to size for bed base, allowing enough to lap up the walls a little. Staple it in place. 

 

Fill your bed with soil, adding some compost or quality manure too.  

 
To calculate the correct volume of material measure length x breadth x depth. In our case 1.2m x 1.1m x 0.3m = 0.396 cubic metres. There are 1000 litres in a cubic metre so this measurement converts to 396L. Bagged garden products are mostly sold by litres so that means this bed needs 400L of bagged product to fill. 

 

Tip: If you can’t fit everything into your car talk to the Trade Desk. They can organise delivery or you can hire a ute or trailer for the task.

 

Step 15.1 Cover base with drianage fabric.jpg  Step 15.2 Fill bed with soil and compost.jpg

Step 16

We used 90mm treated Pine decking to dress our seats, but this is optional. First we covered the edges, then we added slats to the top with an overhang of about 30mm on the sides and 20mm at the front. These we nailed on.

 

Step 16 Optional step Dress seats with treated pine decking.jpg

Step 17

Water the new soil and then plant out as desired. We used a dwarf pomegranate in the centre, a couple of pineapples to the rear and a row of annual sunflowers to the front. These will be replaced every few months with new seasonal colour. Water plants well once planted. 

 
Mulch the garden bed with a fine mulch, water well and enjoy your new planter.

 

Step 17.1 Plant out the bed.jpg  Step 17.2 Mulch well.jpgStep 17.3 Complete.jpg

Materials

  • 200mm x 50mm x 2400mm H4 treated Pine sleepers x 14 (or 28 x 1200mm if available) 

  • 90mm x 45mm x 6m treated Pine (H3 minimum) 

  • Bugle-head batten or construction screws, exterior grade: 25 x 75mm and 150mm, 100 x 100mm  

  • Filter or drainage fabric 

  • Bagged soil and bagged manure or compost (we used eight 50L bags of garden soil and two 25L bags of composted cow manure) 

  • Mulch (we used organic sugar cane) 

  • 90mm x 20mm treated Pine decking (optional).

Tools

  • Power saw  

  • Drill-driver

  • Tape measure 

  • Builders square or rafter square with 45-degree side 

  • 600mm and 1200mm levels

  • Quick-release clamps 

  • Staple gun 

  • Nail gun (optional) 

  • Personal protective equipment – eye and ear protection, plus gloves and dust mask for sawdust.

Images

 

Step 1 - Measure mark and cut all sleepers.jpg

Step 2 - Create corners from 600mm lengths.jpg

Step 3 - Position sleeper in corner align and secure.jpg

Step 4.1 Add sleeper section to long face of corner and secure.jpg

Step 4.2 Check corners with square.jpg

Step 5 Add remaining side boards.jpg

Step 6 Measure between corner posts on sides that will have seats.jpg

Step 7.1 Cut 90 x 45 for seat rails.jpg

Step 7.2 Mark 50mm in from edge of cut sleeper and position rail.jpg

Step 8 Roll over and secure with 100mm screws.jpg

Step 9.1 Measure between seat rails.jpg

Step 9.2 Attach rail to bed face.jpg

Step 10.1 Use square at 45 to mark a series of triangles.jpg

Step 10.2 Attach triangle support bracket to seat.jpg

Step 11 Position seats and screw to corner posts.jpg

Step 12 Add support rails to short sides of inside of bed.jpg

Step 13.2 Fit centre support.jpg

Step 14.1 Add sleepers to rails.jpg

Step 14.2 Screw sleepers down with 75mm screws.jpg

Step 15.1 Cover base with drianage fabric.jpg

Step 15.2 Fill bed with soil and compost.jpg

Step 16 Optional step Dress seats with treated pine decking.jpg

Step 17.1 Plant out the bed.jpg

Step 17.2 Mulch well.jpg

Step 17.3 Complete.jpg

Why join the Bunnings Workshop community?

Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects