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Deck's Requirements Per DCA6-2015

Updated: Nov 27, 2023

I will be discussing some of the recommendation as published in DCA6-2015 (Prescriptive Residential Wood, Deck Construction Guide based on 2015 International Residential Code). This write up is in no way meant to summarize DCA6-2015.

I am not reproducing the document but rather I am highlighting some of the information in it in efforts to make more people aware of such a great resource (free) that is available at everyone fingertips DCA6-2015

Engineers are trained to interpret codes, standards and other requirements of the local jurisdiction, also to use their best engineering judgement, training and education when reliable sources aren't available.

In the pictures below information provided to help builders and home owners determine decks maximum joist spans and overhangs. There are a lot of information available to help people get their projects built, and some of it just free like DCA6 2015.

In the pictures below information provided to help builders and home owners determine decks’ maximum Beam Spans and overhangs also joist-to-beam connection detail as well as beam assembly detail.

In the 2 figures below, I am sharing the recommended post to beam attachment requirements as noted in DCA6-2015.

This attachment below is an example of a prohibited post to beam attachment per DCA6-2015. It is important to note that per the article published in the Structure Magazine in April 17th and written by John Showalter, P.E. And Loren Ross, P.E. (Residential Wood Deck Design, ).

They do state that" It is important to note that prohibiting attachment of the beam to the sides of the post with fasteners only ensures wood -to-wood bearing. The design of fasteners for wet-services conditions requires significant capacity reductions and should be evaluated by a design professional" Based on this statement a more detailed and maybe lengthy calculations would be required to determine whether this indicated attachment satisfy minimum code and engineering requirements or not. For many people avoiding that engineering expense would just simply to comply with the prescriptive code and eliminate such connection.

In the Figures below you will see a few recommended attachment of ledger board to band joist/rim joist and to foundation wall, also you will see the prohibited attachment per DCA6-2015

Typical foundation options also discussed in DCA6-2015 as shown in the figure below

Below you will see an example guard detail so builders and home owners can determine Guard Requirements for all decks that are 30" above grade.

Examples of Guard Post attachments for required guard are shown in the few pictures below.

Pictures below Explain stair & stair stringer requirements also show tread connection, stair guard requirements and stair stringer attachment detail.

I hope I was able to provide some highlights for this great document, DCA6-2015. Also refer back to IRC and IBC for any additional information that is necessary and not discussed in DCA6.

Call us today if you need any further assistance: 724-949-0004

Written by Firas Abdelahad, P.E.

Firas Abdelahad has been a practicing structural engineer since 2005, collaborating with a diverse range of professionals, including consultants, architects, investors, homeowners, contractors, and subcontractors. Together, they tackle the various challenges that can arise during the design and construction phases of projects.


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