# Residential Deck Design Guide (DCA6) by AWC Updated May 2013



## Frank Woeste (Jun 13, 2013)

Visit http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf for details.


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## jar546 (Jun 14, 2013)

Folks, this is MAJOR news.  Please take note!!!

Jeff


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## globe trekker (Jun 14, 2013)

To be applicable and enforceable, the REVISED Guide still must be adopted specifically

by each AHJ though!

.


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## Pcinspector1 (Jun 14, 2013)

O..No.....Mr. Bill,

I noticed under stair requirements that two 2x6's used as treads will not span the 34.5" span so the jacks will need to be brought inward or a center jack added.

pc1


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## jar546 (Jun 15, 2013)

So when is the ICC going to make changes in the span tables?  That is what is limiting enforcement.


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## Frank Woeste (Jun 15, 2013)

Just for informational purposes, some spans in DCA6 will not match the IRC because DCA6 spans are based on "wet service" conditions, whereas the IRC spans are based on dry use (Moisture Content<19%).  Note footnotes 1 and 2 in the joist span table:

"1. Assumes 40 psf live load, 10 psf dead load, L/360 deflection, No. 2 grade, and wet service

conditions. See Figure 1B.

2. Assumes 40 psf live load, 10 psf dead load, L/180 cantilever deflection with 220 lb point load,

No. 2 grade, and wet service conditions. See Figure 1A and Figure 2."

The wet service factor can reduce spans when "deflection limits" do not control the maximum span.


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## jar546 (Jun 15, 2013)

This is the problem with the IRC.  We have known that the DCA6 is wet service but I am still trying to connect it to the IRC legally so that we can use it for enforcement.  We strongly recommend they use it but can't force it unless someone can show me how it legally connects into the IRC.


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## RJJ (Jun 15, 2013)

Well then the question becomes in PA could you adopt the reference? I use it I recommend it and most can't figure out 2009 IRC.


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## peach (Jun 22, 2013)

it comes into best practice; I used to give the deck design guide away (as part of my building safety month budget).


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## RJJ (Jun 22, 2013)

I still give it out for guidance.


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## Glenn (Jun 22, 2013)

jar546 said:
			
		

> This is the problem with the IRC.  We have known that the DCA6 is wet service but I am still trying to connect it to the IRC legally so that we can use it for enforcement.  We strongly recommend they use it but can't force it unless someone can show me how it legally connects into the IRC.


1) You can build something using prescriptive methods in the IRC, or an alternative means and method

2) Alternatives are engineering or testing

3) There is no prescriptive means to build a deck in the IRC, so a builder must go the "alternative" route.

4) There are no pre-tested complete deck assemblies, so engineering is what's left.

5) The Building Official has the authority to review alternatives to determine if they are "equivalent" to the IRC.

6) "Engineering" does not have to mean a signed and sealed drawing for each site, it can be pre-engineered information from "approved" sources.

7) The publishers of the DCA6 are the AWC.

8) The AWC writes the NDS, the bible for wood frame construction and referenced from the IRC

9) The AWC is considered a reputable source of engineering and the BO "approves" it's use as an alternative.

10) The Building Official politely tells the permit applicant that they can use the DCA 6 in lieu of expensive job specific engineering.

It's all in how you present it.  It's not that you're FORCING them to use the DCA 6...that's negative and pushy.  It's that you're LETTING them use the DCA 6 instead of paying for an engineer.  How nice of you.

You can't install an elevator track using the IRC because there are no prescriptive provisions addressing it.  You can't install joists in a wet-use environment using the IRC because there is no prescriptive provisions addressing it.  What you are up against is that though for all of time (technically) decks should have been engineered, they have never been.  Our culture seems to ignore decks when it comes to following the actual path the IRC lays out.  You wouldn't have a problem asking for that engineer for the residential elevator...but the deck...that's tough.  I too cannot demand engineering for every deck in my jurisdiction, as it's not the culture.  However, I can certainly expect that they be built with some kind of validity.  If you approach it this way, you'll be thanked for LETTING them use the DCA 6.

As for getting this fixed in the IRC...

I have been working with the NAHB, AWC, CLMA, NADRA, CCICC, VBCOA, SST, OMG, SMA, and many other interested professionals working to produce quality, prescriptive deck provisions for the 2015 IRC.  Wet-use tables for joists and beams being a large focus.  There are a variety of opinions, ideas and proposals related to decks this year.

Take a look at RB-264 and RB-268.  Both include wet-use span tables proposed for the 2015 IRC.


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## Uncle Bob (Jun 22, 2013)

Disclaimer from AWC:   "Where applicable, provisions and details contained in this document are based on the _International Residential Code (IRC) _[bracketed text references applicable sections of the _IRC_]. Prescriptive construction methods recommended meet or exceed minimum requirements of the _IRC_. Provisions that are not found in the _IRC _are recommended as good industry practice. Where differences exist between provisions of this document and the _IRC_, provisions of the _IRC _shall apply. This document is not intended to preclude the use of other construction methods or materials. All construction and materials must be approved by the authority having jurisdiction. Every effort has been made to reflect the language and intent of the _IRC_. However, no assurance can be given that designs and construction made in accordance with this document meet the requirements of any particular jurisdiction."  My prospective:  Please keep in mind that inspectors and building officials have no authority to suggest or provide building designs.  Any design given to contractors or suggested by employees should be adopted by the governing body ( and not from the building official or the  inspector).  When you do, you take full responsibility for the design.  Uncle Bob


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## jar546 (Jul 24, 2020)

I am unsticking this thread.  It is way, way, way old news and out of date now.


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