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Low-level deck over concrete

Backyardtradie
Building a Reputation
Backyardtradie
Backyardtradie
Building a Reputation

Building a low-level deck transformed the look of this outdoor entertaining area.

 

 

StevieB_0-1629354009106.jpeg

 

The project

 

I built a 3800 x 3440mm low-level deck on a concrete slab. The deck meets the house on two sides, with a 120mm clearance on one side and 110mm on the other, so I decided to keep the deck height just above 110mm.

 

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I used 90 x 45 treated Pine joists sitting on galvanised brackets with about 10mm ground clearance. I was planning on using 70 x 45 joists, but MitchellMc suggested using 90 x 45 to stop the timber from flexing.

 

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I ran the joists in the alternate direction to the decking boards with 400mm spacing on the joists to support the timber.

 

Pre-sanding.

 

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Washed.

 

StevieB_1-1629354033522.jpeg

 

Oiled using Cutek with a matte finish.

 

Final table.JPG

 

Before and after

 

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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

 

Whether you are building a new deck or rejuvenating an existing one, get inspired by the clever and creative Bunnings Workshop community in our Top 10 most popular deck projects.

 

Comments
cathham
Just Starting Out

That looks great ! 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Welcome to the Bunnings Workshop community @cathham. It's sensational that you've joined us, and wonderful to see you're excited about this project.

 

Let me mention @Backyardtradie so they are alerted to your kind comment.

 

Are you considering building a deck at your own home? Something like this project could really transform the feel of your whole outdoor area. Please let us know if you need any assistance, as our knowledgeable members would all be keen to provide any guidance you need.

 

We look forward to hearing all about your projects and plans around the house and garden and encourage you to let us know anytime you need help or have something to share. You'll find tonnes more inspiration within the community, just like this project, and I can highly recommend reading through our Top 10 most popular deck projects for more ideas.

 

It's great to have you on board.

 

Mitchell

 

ssjolly
Finding My Feet

Great outcome @Backyardtradie

I have a question. I was wondering how did you go about fixing the treated pine next to the wall? and which bolts and nuts did you use to attach the timber to the brackets?
Thanks

 

Backyardtradie
Building a Reputation

@ssjolly  Apologies for the delayed response. Screenshot 2021-09-15 172934.jpg

Backyardtradie
Building a Reputation

@ssjolly I had limitations with Hebel hence had to take the longer path as shown below. If you have Bricks- suggest pre-drilling through the wood and brick wall and using fasteners suggested by @MitchellMc . 

Reach out as you need- I am sure you'll have more questions when you progress with the project. 

Good Luck!!

Beachbox
Having an Impact

Beautiful job!

shez_89
Just Starting Out

Hi @Backyardtradie @MitchellMc , 
A noob on this forum but I'm looking to build something very similar to what @Backyardtradie built. I've got an alfresco enclose on three sides. I'm planning to use 90x45 joists and bearers, and am looking to bolt the bearers to the brick walls. There's about a 10mm clearance once all joists and bearers will be installed although wondering if this will be enough (I noticed this being OK on a couple of other discussions). Do have a couple of questions:

* What screws should I use for the angle brackets of the joists to be bolted to the ground? Also, I know I case Dynabolts to bolt the bearers to the brick wall, although what is the recommended length of bolt give I'm using the 90x45.

*What screws should I use for the merbau to be screwed into the frame?

*Is there anything else I need to consider while building the deck? Pain points etc?

 

Cheers

Shez

 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Welcome to the Bunnings Workshop community @shez_89. It's wonderful that you've joined us, and many thanks for your question on deck construction.

 

A 10mm gap under the timber is really the bare minimum. It might allow water to drain, but there will be limited to no airflow under the structure. Time will tell if this becomes an issue that could lead to a premature life span on the deck.  

 

If the ground is concrete, then Dynabolts are also used to fix the joist brackets to the ground. To join the brackets to the joists, you can use Zenith M10 x 40mm Hot Dipped Galvanised Hex Head Coach Screws. You need to space your ledger board off the brick wall, as it can't be placed directly onto the bricks. You can do that with 10mm worth of plastic packers or flashing. Your Dynabolt needs to be 45mm, plus your packers depth and/or flashing and then at least 50mm into the brickwork. You'll likely be looking for something close to a Ramset 12 x 125mm Hex Nut Dynabolt.

 

My recommendation for the screws would be self-drilling stainless steel. They'll save you a tonne of time by not having to pre-drill and countersink every screw hole in the Merbau decking.

 

If you haven't already read through it, @Adam_W's article on How to build a low-level deck is an excellent resource for what to consider when building a deck.

 

Please let me know if you have further questions.

 

Mitchell

 

shez_89
Just Starting Out

@MitchellMc Thanks a tonne for your advice - really helpful. I didnt come across the packers for brick installs but that was a good tip. Are you able to tell me why these are required? 

 

WIth the joists, would a 70x45 be better to go with in that case to allow another for more airflow?

Also what size angle brackets are advisable to use?

 

Cheers

Shez

MitchellMc
Bunnings Team Member
Bunnings Team Member

Hi @shez_89,

 

There needs to be a gap or flashing between your ledger board and your wall as you'll be generally attaching above the brick walls damp course line. If there is no gap, moisture can be transferred from your deck into the wall. If this then gets into the houses' timberwork, there can be issues.


More airflow is always better, though you'll need more supports for the 70 x 45 as it can't span as far unsupported. A bracket similar to the Wesfab 75 x 75 x 40 Galvinised Angle Bracket should be suitable.

 

Mitchell

 

 

shauny
Building a Reputation

@Backyardtradie Your picture framing, is it a 140mm board, with a board laying on its side with an additional 19mm space before your normal decking boards? I like that feature just inside of the wide board.

Faheem
Getting Established

Hi @Backyardtradie , your deck look so professionally done mate. Excellent job! 

i am going to build my own deck as well and need some guidance on the fixings. Whats the name and size of brackets you used to join joists with the concrete slab? And the screws or bolts you used? And the brackets you used to join joist with the beam at the end. 

And i can see you have one frame edging. What should  be gap between the two joists on the edges to support the frame? 

and lastly, i have clearance of 160-170mm. What combination of footings, bearers and joists you recon I should use? 

Thanks mate,

Faheem

 

Faheem
Getting Established

Nice work @Backyardtradie. just a quick one. What type of screws or bolts you used to connect the brackets with the concrete slab?

also, Do you have masonry drill? I have a regular 3amp makita drill. Will that work? 

 

 

DIYImpressions
Having an Impact

@Backyardtradie  How did you manage to get this border done? 

57507176-6E40-4200-97C1-5DD4229D8D8B.jpeg

newhobby
Just Starting Out

Looks awesome! I want to do the similar thing. Can i ask what materials are required?

EricL
Bunnings Team Member
Bunnings Team Member

Hello @newhobby

 

Thank you so much for joining the discussion. Let me tag @Backyardtradie to make them aware of your kind comments. The materials used for low-level decks are often framing timber and decking panels . But before you start I recommend reading this fantastic guide - How to build a low-level deck by @Adam_W. There you will be able to see the general idea of how to plan your deck. I suggest planning it on paper or computer so that you will have a better idea of what is involved in building a low-level deck.

 

Here is a link for ideas and inspiration: Inspiring low-level deck builds

 

If you have any other questions, please let us know.

 

Eric

 

RussF
Finding My Feet

Looks really good, inspirational

Craig-G
Just Starting Out

Hi People,

Very impressed with the updated look of the deck. Would like to consider something similar.

I have a large irregular shaped existing patio with tiles covering concrete. No drumming or loose tiles but very slippery when wet.

Can I just run treated pine slats, 450 centres, in the direction of the existing fall to fix the decking to?

If so, how do I fix these to the tiles/concrete?

Thanks

EricL
Bunnings Team Member
Bunnings Team Member

Hello @Craig-G

 

Welcome to the Bunnings Workshop community. It's fabulous to have you join us, and thank you for sharing your question about installing a low-level deck over tiles.

 

Unfortunately, if the timber slats are in direct contact with the tiles you'll get moisture contamination which will greatly shorten the life of your proposed deck. Not only that, but the slats being very thin will create a spongy deck and will provide no support to the decking panels. In regards to this type of installation, I recommend using treated framing timber in H3. The size of timber that you can use will depend on the clearance you have between your door and the floor area.

 

If you look at the second picture of the article you'll see that timber framing is below the door assembly. It has just enough space to install the decking panel. The timber framing is installed with angled brackets which are screwed down with Dynabolts onto the concrete base. In your case, you'll need to drill through the tiles and into the concrete base. It's not enough that the frame is only mounted to tiles.

 

Here is a link for ideas and inspiration: Inspiring low-level deck builds

 

If you have any other questions we can help with, please let us know.

 

Eric

 

makhan006
Just Starting Out

Hi

 

i like your project and i am planning to build similar . Could you please share the list of stuff i required for this?

Thanks

EricL
Bunnings Team Member
Bunnings Team Member

Hello @makhan006

 

It's great that you've been inspired by this decking project. Let me tag @Backyardtradie to make them aware of your kind words and question. 

 

Please keep us updated with your progress, we look forward to seeing the start of your decking project.

 

Eric

 

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