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Deck footing

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Deck footing



I was hoping someone could help me understand the plans for the footings certificate I have received for my deck? From what I gather I need to dig holes of 1.2m, fill that with 800mm of concrete and and then sit my stumps in at least 450mm below ground level? This was set by council and seems like overkill.

I also have to cut the site to allow for 200mm spacing on the underside of the bearers and have to move a lot of dirt in doing so. Any recommendations for this? Thinking a Kanga Digger. 


Thanks for any help! 



Bunnings Team Member
Bunnings Team Member

Re: Deck footing

Welcome to the Workshop community @trentp. It's great to have you join us, I'd be happy to kick-off the discussion.


What you have mentioned certainly seems to marry up with the plans supplied. I can't help you out with whether they are "overkill", but perhaps @ProjectPete might have some advice. I do know that a letterbox should at least have a 30cm x30cm x 30cm cube of concrete to keep it secure in the ground, so for a footer supporting the weight of the deck it doesn't particularly surprise me.


Depending on how much dirt you have to move a Kanga Digger could certainly save a sore back.




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Kind of a Big Deal

Re: Deck footing

At first glance it can seem like overkill but there are several factors involved such as local regulations, height of deck, weight of deck (especially if there'll be a gazebo/pergola/spa on top), soul type, etc.


Generally speaking 400D X 300W X 300W is sufficient allowing for compacted base, concrete to be pour under the post and all around it (100x100 H4).


It's important you first a) question/challenge the engineer (espesh as they're known for over-engineering things), and b) build to the final specs because there'll be good reason to do so.


Sand removal (an it's important to get the right clearance) - hire a kanga, or pay someone on Gumtree $18-20hr cash to dog it for you. Only H4 requires the clearance so you don't need to worry so much around H4 (posts and sometimes other parts of your frame are H4).

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