Merbau decking over concrete slab

[Neo19]

Hi Everyone 

I have been going through these discussion boards for a while and finally mustered to courage to post a question here

This would be my first deck. Have done some landscaping for myself in the past including a raised garden bed, however nothing major. As far as tools, I've a drill kit including hammer drill, a cordked circular saw and a random orbital sander. 

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My proposed deck would be 350 x 370 with height from the slab between 17 - 18 cm so it stays flush with the brick and same level as my internal floor. 

I've been advised that i could use H3 structural timber (140 x 45) as joists and lay decking boards on top that. 

My questions, 

1. How do I attach joists to the concrete? Use galvanized angle brackets like this?

2. How can I adjust the height so the finished decking board stays flush? If i used 140 board + .5 bracket + 19 mm board = it would be around 165 cm height. Which is around 1.5 cm lower than bricks. Can I use plastic wedges / window packers to compensate for around 1.5 to 2 cm? 

3. This deck would be under alfresco cover and under eaves. In terms for water drainage, what would be helpful. Would the packers / wedges mentioned in Q. 2 help with the same?   

AlfrescoRough plan showing pillar

On the last image, pillar is on the corner of the alfresco slab and the decking to the south of it would be on top of soil (this would 370 x 45 cm). Not much height difference from alfresco slab. What do I need to provide here under joist for support? Not enough height for a stirrup. 

Thank you very much for reading through. 

Community manager's note: Check out How to build a low-level deck for expert advice.

[Jason]

Many thanks for joining in the discussion @Brendon_B. Great to see you have been inspired by @Neo19's work. Feel free to post anytime you need a hand or have something to share. We have loads of helpful, clever and creative members sharing advice and inspiration every day. 

Welcome to Workshop,

Jason

[devin]

 

Hi @Jason & @Brad, we just moved into our new house and I’m about to embark on my first DIY project, decking the front patio. After spending hours researching, Neo’s project is the best I’ve come across so far.

I’ve got a couple of questions though, bear with me as these may be quite

trivial.

1. Would you need two brackets on either side of the sleeper? I assume so, even though I can’t see them on the pic that Neo had posted.

2. Would you use screws or nuts and bolts to secure the brackets to the sleeper?

3. There’s a tiny bit of water that comes in when it rains which might leave a bit of moisture behind. I was planning on using 140x45mm H3 sleepers, would these work? I was wondering if I should look for H4 sleepers in 140x45mm.  

[MitchellMc]

Welcome to the Workshop community @devin. Many thanks for your question, I'll be happy to assist.

From the brackets laid out which haven't been attached and from what I can see, it appears only one bracket has been used in the fixing of the bearers here.

You would use bolts to secure the brackets to the bearer.

H3 pine is treated to resist moderate decay. If moisture is trapped within the deck it can increase the rate of decay. Perhaps the brackets could go under the bearers raising them slightly giving the water a chance to flow out. I'm sure @Brad can advise if this is even an option.

Mitchell

[Brad]

I think instead of trying to fix with the bracket under I would rather use a packer or wedge to get at least some gap between bearer and concrete so water won't pool like it would if it was a tight fit. H4 is not a bad idea when your tight with space and there is water around.

[devin]

@MitchellMc & @Brad thank you! I didn’t expect such a prompt reply, you guys are champs!

I’m going to get the timber, brackets, etc for the frame tomorrow. After factoring in 140mm for the bearer and 9mm for the decking, I’ve got about 20mm left for the decking to sit flush with the step at the entrance. I think I’ll use spacers to compensate, and hopefully this will leave enough of a gap between the concrete and the bearer for any water to drain off. 

Since it’s a small project, I actually wouldn’t mind spending a little extra for H4, but couldn’t find 140x45mm on the site, hopefully I’d have better luck at the store. 

[MitchellMc]

@devin,

If you need further assistance or would like to share your project with the community, please feel free to start a new discussion. We look forward to seeing your new deck come together.

Mitchell

[Brendon_B]

 

 

 Deck completed!!

Couple months of Saturdays...

Really happy with the results.

Kept it simple as possible

Only issue was fighting with warped decking boards.

[MitchellMc]

Hi @Brendon_B,

Well done on constructing a deck that compliments the area perfectly! I am sure you are proud of your efforts and rightly so as the area looks significantly more functional than before. You'll just need a small 3pc setting and it will be fit for morning coffees whilst admiring your handiwork.

Many thanks for updating us on your deck. We look forward to seeing what other projects you have going on around your home and garden.

Mitchell

[Brendon_B]

 

 All over it Mitchell...

Thanks to Bunnings....

[babakr]

@Neo19

The deck looks fantastic. I want to choose deck boards with exactly same colour and finish like this. Can I ask what type of boards or stain did you use?