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Low-level Merbau deck over concrete

Having an Impact
Having an Impact

This low-level Merbau deck was built over concrete and features picture framing and deck lighting.





The project


I built a low-level Merbau deck with picture framing. It was a 24sqm decking project over concrete with a ground clearance of 120mm.


Inspiration was taken from Neo19's Low-level Merbau deck over concrete slab and this deck project wouldn't be possible without the help of EricL and MitchellMc answering my endless questions in my Building a low-level deck over concrete discussion.

I started drilling with my old Black & Decker 500W Drill, but within 30 minutes I decided to get a new one. The Ozito 900W Rotary Hammer Drill made my work a lot easier. I made 90 x 60mm holes in concrete without any issues.




I used 19 joists (90 x 45) with a span of 450mm. The first two and last two joists were spanned at 70mm for picture framing. The joists were supported by five angle brackets in random positions to avoid twisting. This eliminates the need for noggings. The space between the Merbau panels is kept at 5mm with the help of Deckhand and Macsim Spacers and 2–3mm at butt joints.




Joist placement for picture frame border.




I drilled holes in the timber to route the deck lighting cables and created a Merbau junction box near the switchboard for easy wire routing under the deck. This allows me to only remove part of a panel if needed instead of removing an entire Merbau panel.






It took me eight days to complete this project. The most difficult part was straightening the Merbau panels.













Here is the materials used for this 24sqm deck and the cost:


Decking for 24SQM Qty Unit Price Total
90 x 45 Joist 3 meter (450mm span)  19 21 399
Dunnings 40 x 80 x 40 x 5mm M12 Galvanised Angle Bracket 95 2.82 267.9
Zenith M12 x 65mm Hot Dipped Galvanised Cup Head Bolts And Nuts - 12 Pack for Joist 8 14.1 112.8
Zenith M12 Hot Dipped Galvanised Washer per piece on the nut side 95 0.31 29.45
Ramset 12 x 60mm Galvanised  DynaBolt Plus Hex Nut Bolt for floor 25 per pack 4 35 140
Zenith M12 Hot Dipped Galvanised Washer per piece for both sides 110 0.31 34.1
TWA Woodcare 300g Ecoseal Tanalised Timber Treatment 1 15.9 15.9
Zenith 14G x 150mm Galvanised Type 17 Batten Bugle Head Timber Screws - 25 Pack 1 18 18
The Deckhand Easifit Template Guide - 2 Pack 1 19 19
Protectadeck 45mm x 50m Flexible PVC Joist 1 55 55
Ozito Hammer Rotary Drill 900W 100 1 100
Ozito Mitre Saw 100 1 100
60 mm 304 Decking Screws box 250 1 250
Merbau (140mm) 183 Linear Meter 183 9 1647
Hollman Lights 331 1 331
Craftright 3pce Countersink Bit Set and Craftright 8 Piece Spade Bit Set  14 1 14
Macsim 72 x 100 x 1mm Brown Half Shim - 10 Pack 2.98 1 2.98
Macsim Fasteners 72 x 100 x 3mm Green Half Shim - 6 Pack 3.15 1 3.15
Macsim Fasteners 72 x 100 x 5mm Yellow Half Shim - 4 Pack 2.8 1 2.8
Total     3542.08


How to build a low-level deck


A low-level deck can pose a range of potential design and installation problems, with particular challenges around ventilation, drainage, termites and rotting. But it doesn't have to be a difficult project once you take the time to understand the basics of how they are put together.


Experienced Bunnings Workshop member Adam Woodhams has created a comprehensive guide to building your own low-level deck which should provide an excellent reference for getting started. 


More inspiration for your deck


A deck can help extend your living area and provides a fantastic space to relax and entertain friends and family. For more inspiration for your outdoor area, check out our Top 10 most popular decking projects and these Inspiring low-level deck builds.


Finding My Feet



Great job mate looks great and did well with the lights. One question I do have is why did you put all the joins in a straight line and not stagger the joins? 

Bunnings Team Member
Bunnings Team Member

Hi @Thurlo90


Let me tag @DIYImpressions to make them aware of your kind words and question. Are you planning on making your won low-level deck? If you have any questions or need assistance, please let us know. Our members would be more than happy to provide advice and information.




Having an Impact

@Thurlo90 apologies for late reply. Reason to put joins in straight line was to minimise the cutting and i felt it easy to install it. I laid the joists in a way that I was able to use one full merbau plank (4 meter) without cutting it. It was the second plank which I had to cut (3.5 meters) 

Finding My Feet

Very well explained 

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