Deck posts max distance

I don’t known if I missed it …but so far I haven’t see any requirement when it comes to max distance between 2 posts ( or footing) for a deck foundation. There is for handrail post but nothing for underneath the deck…?

The beams span dictates the posts and footings.

Hope this was helpful

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This should help you.

DCA6 Prescriptive Residential Wood Deck Construction Guide Based on 2015 IRC (

Ideal deck post spacing is 8 feet or less. The distance between deck support posts depends on the type of wood species used and the size of the joist and beam. There is no minimum span.


But there sure are a lot of maximum spans!!

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Here is a general span chart to give you an idea of what I meant.

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Thanks for the infos!

Diagonal bracing on center post allowed or not?

So, it depends on what your state adopts. Here in GA, you can use either the AWC prescriptive deck guide or the GA amendment prescriptive deck guide. Just as you indicated, the AWC does not allow for center bracing, but our GA amendment does.

I’ve never heard of not allowing center bracing. Someone enlighten me please.

The American Wood Council has a residential prescriptive wood deck guide that many states adopts for deck construction. This 2012 version of this guide prohibits center bracing as seen below:
Now, your state may use this guide are make their own.

Here is a copy for you.
AWC-DCA62012-DeckGuide-1405.pdf (3.9 MB)

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I was never doubting the rule, I was questioning the reasoning behind it.

Damned if I know? LOL My state contradicted itself.

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Thanks Brian. On a higher deck I think aesthetically it looks better having diagonal bracing on all posts. I was just curious.

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Diagonal bracing can contribute to the stiffness of the deck and, therefore, cause additional lateral loads on the posts. Since center posts receive more vertical load than corner posts, the additional lateral load can cause overstress. For this reason, DCA 6 does not show the use of diagonal bracing on center posts.

The lateral force applied to corner posts is based on the capacity of the connection at the brace.,the%20connection%20at%20the%20brace.


Great article! Thank you!

I always want to know the “Why”. Knowing the why’s makes it easier to retain the information and explain an issue to the consumer.

:+1: :+1:,the%20connection%20at%20the%20brace.

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Thank you Marcel!