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How to build a floating planter box

Trusted Contributor

Difficulty: Intermediate

For a stylish way to bring new life to a room, build a floating planter box to showcase some beloved plants.


Using basic materials and simple woodworking skills, you can achieve this project in a day and have something to admire for years to come.


Step 1

Measure your wall space and decide what sized planter box you would like. Use the formula below to determine the amount of timber required. This is based on using 140x19mm dressed pine.


  • Length of front - this is the one measurement you need to know to begin.
  • Length of back = front minus 38mm.
  • Length of base = same as back.
  • Length of sides = 140 + 38mm = 178mm.

Step 2

Cut your material to the required lengths which you’ve calculated in Step 1 and follow the guidance on cut angles below.


  • Front – The two short ends should be mitre cut at 45 degrees.
  • Back and base – These consist of 90-degree cuts on both ends.
  • Sides – One end (the front end) is to be cut at 45 degrees while the other end (the back) is 90 degrees. The reason for varied cut angles is to reduce the number of visible joins for a seamless finish.


Step 3

Once you’ve done the cuts, tidy up the cut ends with some 400 grit sandpaper, then lay the timber out and ensure a snug fit. Now we are going to move onto gluing it all together.


3.1 Use 400 grit sandpaper.jpg  3.2 Corner sanding.jpg  3.3 Lay the timber  out.jpg  3.4 Ensure a snug fit.jpg

Step 4

To glue the two mitre joins at the front of your box you can either use corner clamps or a little trick with some tape as you can see in the photos below.


Once your mitre joins have dried as per the instructions on your chosen glue, proceed to gluing the rest of the box together. Pop the base on, then the back.


If you have a Brad nailer, it makes finishing quicker as you can avoid some clamping. To avoid touching up small nail holes, just use nails on the back where they won’t be seen anyway.


4.1 Use corner clamps when gluing.jpg  4.2 Tape trick alternative to clamps.jpg  4.3 Using tape.jpg  4.4 Glue the rest together.jpg  4.5 Gluing finished.jpg

Step 5

Clean off any excess glue that’s oozed out of the joins then drill at least two holes in the back panel of your box to allow fixing to the wall with the sleeve anchors. Place it on the wall where you wish to hang it, level it with your spirit level and mark the points to drill into the wall. Note: if you are fixing to a timber wall you need the appropriate fixings and to locate the studs.


Step 6

Fill any gaps or joins that need filling and sand any areas that need it before finishing it in a style that matches your home décor. You can oil it, stain it or even paint it. It’s really up to you.


Note: don’t waste time oiling/painting the inside of the box as it’ll be lined with black plastic in the next step. Just go about 15mm down from the top on the inside for a clean finish.


Drill the holes in the wall and insert the sleeve anchors while you wait for the box to dry.


Step 7

Cut the black plastic to suit the shape of the inside of your box ensuring you overlap pieces by about 15mm. Apply silicone to the inside of the box to hold the black plastic in place. Apply silicone to where the plastic overlaps so you have a waterproof seal (preventing the moisture from the soil coming into contact with the timber box). Make small holes in the plastic where the drilled holes are.


Step 8

With the holes drilled in the wall, place your planter box onto the sleeve anchors and fasten it in place with your socket set or spanner.


8.1 Finished box.jpg

Step 9

Fill the box with a quality soil and your favourite plants.


Next time try using bamboo cladding for a different effect. You can be creative with the materials you use and the way you finish the box. Enjoy!


9.1 Finished box in bamboo.jpg  9.2 Finished box filled.jpg


  • Personal protective equipment
  • 30mm painters tape
  • Quality PVA wood glue
  • Dressed pine (based on desired size) or other timber
  • 400 grit sandpaper
  • Timber filler to match your material
  • Black garden/builders plastic
  • Clear roof and gutter silicone
  • 2-4x 10x75mm hex head sleeve anchors (for fixing to brick wall)
  • 25mm C1 18 gauge Brad nails (optional)


  • Ruler
  • Tape measure
  • Spirit level
  • Pencil or sharp texta
  • Mitre saw
  • Clamps and corner clamps
  • Hammer drill
  • 10mm timber drill bit
  • 10mm masonry drill bit
  • Socket set or adjustable spanner
  • Caulking gun
  • Cloth
  • Stud finder (for timber frame houses)
  • Brad nailer (optional)


3.1 Use 400 grit sandpaper.jpg

3.2 Corner sanding.jpg

3.3 Lay the timber  out.jpg

3.4 Ensure a snug fit.jpg

4.1 Use corner clamps when gluing.jpg

4.4 Glue the rest together.jpg

4.2 Tape trick alternative to clamps.jpg

4.3 Using tape.jpg

4.5 Gluing finished.jpg

8.1 Finished box.jpg

9.1 Finished box in bamboo.jpg

9.2 Finished box filled.jpg

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