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Building a low-level deck over concrete

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Building a low-level deck over concrete

Preview of the finished resultPreview of the finished resultHello Team, i plan to build a deck outside within the shed area over concrete area.


Dimensions are 8 meters x 3 meters. Ground clearance at the entrance  (left side) is 120mm but on the right side window clearance is 170mm.


I want to build a deck with merbau 140mm running to parallel to house with picture frame design. 






Also i want to lay pebbles at the edge of decking like this


I have read the “Building low clearance guide” and want advice on lengths required to start the project. Appreciate your guidance. Thanks

Established Contributor

Re: building a deck

regarding butt join, do I keep a space between them? @EricL @MitchellMc 


1- Any space between picture frame board to horizontal boards?

2- Any space between two horizontal boards? I have read somewhere that these joints should be bevelled at 45 degrees so that only two screws can be used instead of four when two boards joining on a joist.


Bunnings Team Member
Bunnings Team Member

Re: building a deck

Hello @DIYImpressions


It's always advisable to keep a gap between the decking panels even when you are up against the picture frame. However, when you have two decking panels meeting horizontally, it will be up to you how you wish to join them. Some leave a gap to allow for timber expansion. Others do what you've described and cut the decking panel at an angle so that there is room for expansion. I recommend doing a sample layout without the fixings to give you an idea of where the joins will be. You can then plan it out before you start cutting the panels.


Here are some amazing low-level decks our Workshop members have shared: Inspiring low-level deck builds


If you need further assistance, please let us know.




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Established Contributor

Low Level Merbau Decking for 24 Sqm

Dear Community members, 


I have finally finished my deck and will try to give as much details as possible. Special thanks to @EricL and @MitchellMc for answering my endless questions. Questions can be found here ( This job wouldn't be possible without them. Inspiration was taken from @Neo19 project.

Project Details:

It was a 24sqm decking project with a ground clearance of 120mm over concrete. I started drilling with my old Black & Deck 500 Watt drill but in 30 minutes I decided to get a new one. Ozito 900W rotary hammer drill made my work a lot easier. I have used 19 joists (90 x 45) with a span of 450mm whereas the first two and last two joists were spanned at 70mm for picture framing. Joists were supported by 5 angle brackets in random positions to avoid twisting. This eliminates the need for noggings. I also drilled holes in timber to route the deck lightning cables. Also created a Merbau junction box near the switchboard for easy routing of wires. This will allow only to remove part of panel instead of removing entire Merbau panel. It took me 8 days to complete the project. The most difficult part was to straighten the Merbau panels. Space between the Merbau panels is kept at 5mm with the help of deckhand and Macsim spacers and 2-3mm at butt joints.


Below is the Bill of Material used:

Decking for 24SQMQtyUnit PriceTotal
90 x 45 Joist 3 meter (450mm span) 1921399
Dunnings 40 x 80 x 40 x 5mm M12 Galvanised Angle Bracket952.82267.9
Zenith M12 x 65mm Hot Dipped Galvanised Cup Head Bolts And Nuts - 12 Pack for Joist814.1112.8
Zenith M12 Hot Dipped Galvanised Washer per piece on the nut side950.3129.45
Ramset 12 x 60mm Galvanised  DynaBolt Plus Hex Nut Bolt for floor 25 per pack435140
Zenith M12 Hot Dipped Galvanised Washer per piece for both sides1100.3134.1
TWA Woodcare 300g Ecoseal Tanalised Timber Treatment115.915.9
Zenith 14G x 150mm Galvanised Type 17 Batten Bugle Head Timber Screws - 25 Pack11818
The Deckhand Easifit Template Guide - 2 Pack11919
Protectadeck 45mm x 50m Flexible PVC Joist15555
Ozito Hammer Rotary Drill 900W1001100
Ozito Mitre Saw1001100
60 mm 304 Decking Screws box2501250
Merbau (140mm) 183 Linear Meter18391647
Hollman Lights3311331
Craftright 3pce Countersink Bit Set and Craftright 8 Piece Spade Bit Set 14114
Macsim 72 x 100 x 1mm Brown Half Shim - 10 Pack2.9812.98
Macsim Fasteners 72 x 100 x 3mm Green Half Shim - 6 Pack3.1513.15
Macsim Fasteners 72 x 100 x 5mm Yellow Half Shim - 4 Pack2.812.8
Total  3542.08

Pre Decking 1Pre Decking 1Pre Decking 2Pre Decking 2PrepPrepIMG_6808.JPGEasy Drilling with Rotary HammerEasy Drilling with Rotary HammerIMG_6909.JPGIMG_6910.JPGIMG_6911.jpgIMG_6913.JPG

Deck layingDeck layingIMG_6921.JPGIMG_6920.JPGIMG_6922.JPGHo Ho Ho..time for gatheringsHo Ho Ho..time for gatheringsIMG_6945.JPGJunction box for easy wire routing under deckJunction box for easy wire routing under deckFinally...Finally...IMG_6996.JPGIMG_6998.JPGIMG_6999.JPG

Re: Low Level Deck for 24 Sqm

Wow it looks incredible @DIYImpressions and ready just in time for all those summer gatherings.


Thanks for sharing so much detail too. With such a fantastic finish, this project is bound to inspire many community members with their decking projects.


Well done!




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Established Contributor

Re: Low Level Deck for 24 Sqm

Thank you @StevieB it took me a-lot of time to plan and execute. Not all information is provided for this task so I decided to give back to the community with what i learned from all the members and other people. Hope others can benefit from this post. 

Re: Low Level Deck for 24 Sqm

Congratulations @DIYImpressions, the deck looks fantastic. 


I'm sure it will inspire many others. Many thanks for sharing. 




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Re: Low Level Deck for 24 Sqm

Excellent job, @DIYImpressions! I'm so pleased we've been able to assist you along the way, and thank you so much for taking the time to put this post together. Now, not only can our members see your sensational results, but they can read through the complete journey of how you got there. You've really painted the complete picture for everyone.


I'm sure you are very proud of your efforts and rightly so. Well done.




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Trusted Contributor

Re: Low Level Deck for 24 Sqm

Looks fantastic! :smile:


Once the guests are seated and the drinks just keep on coming - are those chair back legs getting closer to the edge?




What are your thoughts on the Ozito rotary hammer drill - a good purchase?



Established Contributor

Re: Low Level Deck for 24 Sqm



If you notice again, chairs are already outside the table. They do get close to the edge but we didn’t had any instance where guests had trouble. I can take a picture if you want. 

Yes it was a good purchase. I made 90 x 60mm holes in concrete without any issues. You can go for 1600W if you need to dig deeper or for any other heavy duty jobs. 

Re: Low Level Deck for 24 Sqm



"I can take a picture if you want."


No thanks mate - I'm sure it's a photographic illusion above. I have a similar sized area I've considered decking and played with chairs, tables and a tape measure and there's enough room to walk past seated guests who've pushed themselves away from the table - post meal. But my chairs are the traditional straight back with perpendicular legs.


Thanks for the Ozito feedback! I have one from around 2008 and still going strong so just wondering how the new ones are.



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