Workshop
Ask a question

The Bunnings Workshop community can help with your home improvement projects.

How to build low-lying deck over concrete and lawn?

SMUCKY
Community Newcomer

How to build low-lying deck over concrete and lawn?

Hi all - new here & hoping to maybe have some questions answered regarding some upcoming work im planning at my place!

We have a small backyard that is half concrete/half grass, we are wanting to make the 47m2 space more useable so am planning on decking over the whole thing essentially with a roof covering over the top one day too. Due to poor drainage in the existing grass area I will be starting off by making the drainage sufficient, concreting in the posts, & then covering essentially the whole backyard in blue metal then build the deck over the top. Due to the small height I have (70mm) ontop of the slab I will be using ClickDeck's extra low profile system to make the job possible. Then due to the small clearance in the grass area I have, the deck will be a single-level deck design & I will be leaving the finished height of the ground below much lower than it is currently as to avoid moisture issues under the deck.

My question is, judging by my rough plans I drew up. Am I in the right direction? Do I have too much framing as it does seems like a lot. Although I have based most of my measurements off of others advice but wondering if its overkill.

Essentially plan on concreting in posts, notching out posts to sit joists on & running a joist only system with hangers in place due to my overall clearance.

I'm aware of council requirements on decks & will have to alter the design to suit.

I'll include photo of what the backyard looks like now as well as my plans.

 

Thanks in advance!

 

BlakeDeck-revision2.jpgIMG_0323.JPGclickdeck.jpgIMG_0232.JPG

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to build low-lying deck over concrete and lawn?

Welcome to the Bunnings Workshop community @SMUCKY. It's wonderful to have you join us, and many thanks for your question about building a deck.

Your plan looks solid, and it's clear you've put a lot of thought into it. The spans you’ve chosen are within the recommended limits, which is exactly what I would suggest. While it’s possible to push the spans further, this can result in a deck that feels a bit bouncy underfoot, so what you have now should provide a sturdy and stable finish.

 

Addressing the drainage issues and concreting in the posts sounds like a smart approach, especially with the low clearance and potential moisture concerns. By creating the single-level deck with ample ventilation underneath, you’ll reduce the risk of moisture build-up, which is key for the deck's longevity.

 

Overall, your layout looks good for the space and conditions you've described. However, remember to approach the council, as if a permit is required, you might also need to employ the services of a draftsperson to create plans for submission. Ultimately, they'll decide if your approach is appropriate.

Please let me know if you have any questions.

Mitchell
 

See something interesting? Give it the thumbs up!

Re: How to build low-lying deck over concrete and lawn?

deck-revision2.jpeg

Hey thanks for the good info @MitchellMc!

 

I am thinking about having the edge of the deck along the footpath come down and over and have a fascia board the whole way along. Or potentially even have a step depending once I figure out the height of the existing concrete as it might be a large drop off. My concern though is getting my posts as close to the edge as possible it probably won’t be close enough so my fascia board hangs over the footpath. To do this would I have to double up (or triple) on my bearer closest to the footpath so to give me more overhang from the last post?

And is it easy enough to incorporate steps in? I was thinking having a step in from the edge. Are there any guides on here with maybe something similar? 
I have highlighted in orange roughly where my fascia board would overhang and in purple roughly where the step would go.

 

What do you think?

Cheers

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to build low-lying deck over concrete and lawn?

Hi @SMUCKY,

 

For the overhang, dropping the bearer down below the joists and running them across the top of the bearer to your desired overhang would work. This will create a cantilevered effect that gives you the extra overhang without needing to double or triple up on the bearer. By having the bearer below the joists, you can still ensure structural integrity while allowing the fascia board to extend over the edge.

 

As for incorporating steps, they can be a little tricky, but nothing too complicated for an experienced D.I.Y.er. The height of the deck and the drop from the existing concrete will determine the size and design of the steps. If you can provide those measurements, I’d be happy to assist you in creating a design for the frame of the steps. Typically, you’ll want the steps to be comfortable to use, with each step’s rise being no more than 190mm, and the tread depth should be around 250mm or so for stability. While I don’t know of any guides specific to step construction for decks on the site, building the frame for steps is very similar to constructing a deck frame—just on a smaller scale and at the appropriate height.

 

Mitchell

 

See something interesting? Give it the thumbs up!

Why join the Bunnings Workshop community?

Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects