Decking Joists - minimum size

11 Aug 2012
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United Kingdom
Hi all, I'm about to move on to stage 3 of my current garden project and install a deck area where I've recently build a shed and fenced area. My deck will be spanning an old concreted area and a soil area - I've research on the site around various aspects of the deck (from gaps between joists etc) but what I'd like to get some advice on is the minimum thickness of the joist themselves.

For reasons relating to my shed door (and not wanting to cut it down) I need to keep the deck as low as possible so would ideally like a thin joist but how thin can I go ?
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that completely depends on the span and method of supporting them?

You could happily have 4x2 or even 3 x 2 if it was supported very well.
Thanks for the response - the total size of the area will be 5x3.6m with 2.8x3.6 of that over an old existing concrete base and the rest over soil. Will support the area over concrete on slabs and was intending to use posts for the area over soil. If I over support it everywhere would 3x2 be okay?

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