Engineered connectors required at cantilevered joist attachment to deck rim joist?

[Michael Thomas]

My understanding is that engineered connectors (typically, joist hangers) are required at all connections of deck joists the rim joists. Yesterday I inspected an otherwise extremely well constructed deck which lacked connectors at the cantilevered end of the joists, and I decided before write them up to confirm that they are required - however looking at the diagrams in the AFPA "Prescriptive Residential Deck Construction Guide" http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf I see that they're not illustrated for connections of cantilevered joists to rim joists. I can understand the logic of this given that the rim joists are not connected to a structure transferring loads downwards to the ground, however something more than nails through the rim joistwould seem to be desirable, if only because the posts supporting the railings are also likely tying in at this junction . So... does the IRC require engineered connectors at this location, or not? - Thanks

[Jim Luttrall]

I believe the same document figure 25 has detail with guard rail.

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

[Jerry Peck]

If a railing is involved then hold-down anchors are required. Joist hangers are not, rail or not.

The reason joist hangers are not required is that joist hangers are for ... 'hanging joist from' the joist hangers, whereas the rim board is not supporting the joists (the joists are not 'hanging from' the rim board).

[chris mcintyre]

The document posted by Michael T. says, "based on the 2009 IRC." Figure 17 says a ledger board may not be attached through exterior veneers (brick, masonry, stone), the deck must be free standing.

Question: Is this new for 2009? If not, can someone tell me where this is in the 2006 IRC.


Michael Thomas, good document, thanks for posting it.

[Jerry Peck]

It is not a change per se, but more of a clarification. This is from the 2006 IRC.

- R502.2.2 Decks. Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be selfsupporting. For decks with cantilevered framing members, connections to exterior walls or other framing members, shall be designed and constructed to resist uplift resulting from the full live load specified in Table R301.5 acting on the cantilevered portion of the deck.

I take that as clarifying what is meant by "positively anchored to the primary structure" / "positive connection to the primary structure".

I.e., that means a "positive connection to the structure itself".

Would you anchor the deck to "paint"? To "stucco"? To "EIFS"? If not, then why would you anchor it to "veneer" which is itself only anchored to "the structure" with brick ties?

[Michael Thomas]

Chris,

It was in the 2007 supplement:

R502.2.2.2 Alternate deck ledger connections. Deck ledger connections not conforming to Table R502.2.2.1 shall be designed in accordance with accepted engineering practice. Girders supporting deck joists shall not be supported on deck ledgers or band joists. Deck ledgers shall not be supported on stone or masonry veneer.

Professional Deck Builder: New Ledger Attachment Requirements Adopted (http://www.deckmagazine.com/article/47.html)

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Thanks to everyone for your replies to the original question.

[C.Johnson]

There is no need for Joist Hangers on the rim board, waste of money and time. I have installed many decks around town. The Rim boards purpose is to prevent the joists from twisting under the decking, hurricane straps or toenailing is used to prevent upheaving in high winds secureing the framed decking to the support beam. My biggest concerns when looking at decks is the connection to the house and the support beam as well as proper sized joist, looking at your photo i'm more concerned with the fact the support post is shimed and shows no true connection to the foundation pier, also the outside joist is not being provided a proper bearing to rest on. What looks to be a 2x2 at an angle to the post is not sufficient. The carriage beam should continue all the way out to the last joist. Just my 2 cents...;)

[Jerry Peck]

JP: Though I think I understand your need to assert yourself from time to time, this is an absurd statement, even by your standards . . .

Aaron,

So ... you are saying that the joists ARE hanging from the rim board? :confused:

Talk about being absurd ...

[Jerry Peck]

Please illustrate to me where I said that the joists were "hanging from" the rim joist.

Where you implied that joist hangers are not called "joist hangers" because they are used to hang joists ... jeez, make up your mind.:p :D

[H.G. Watson, Sr.]

2009 IRC 502.2.2.3 Lateral resistance requirement for Decks that are supported by an exterior wall must be positively attached to the structure and designed for lateral and vertical loads (2009 IRC Section 502.2.2 Introduced a requirement for positive attachment of decks to the structure).Minimum 1500 lb lateral load.Threaded rod through the wall and engineered tension devices installed on either side with approved and properly sized fasteners are one approved method for lateral restraint.

[Jerry Peck]

I will change the pertinent highlighting to bold red with underlining ...


2009 IRC 502.2.2.3 Lateral resistance requirement for Decks that are supported by an exterior wall must be positively attached to the structure and designed for lateral and vertical loads (2009 IRC Section 502.2.2 Introduced a requirement for positive attachment of decks to the structure).Minimum 1500 lb lateral load.Threaded rod through the wall and engineered tension devices installed on either side with approved and properly sized fasteners are one approved method for lateral restraint.


HG: Good point, but no 2009 adoptions in my area.

That deck is not "supported by" anything at that rim board. :D

[Jerry Peck]

JP: I'm not sure what color paint you've been huffing . . . chartreuse? . . . nowhere in my posts did I say anything about the deck being supported by the rim board.


You did not say anything about the deck being supported by the rim joists, but ... :p ... when H. G. provided a section which referenced precisely that type of support, and you said "Good point, but no 2009 adoptions in my area.", which implied that you agreed, and that the discussion was about that support.

If that you are not your intent, you are free to admit it here, which would (hopefully) solve your confusion. :)

[Fred Comb]

My understanding is that engineered connectors (typically, joist hangers) are required at all connections of deck joists the rim joists ... however something more than nails through the rim joistwould seem to be desirable, if only because the posts supporting the railings are also likely tying in at this junction . So... does the IRC require engineered connectors at this location, or not? - Thanks

I'm curious, what gave you the understanding that engineered connectors are required at all connections of deck joists (even cantilevered joists)? I teach classes so I'm always interested to learn the cause of misinformation, thanks.

FYI, IRC can be purchased here:
ICC - International Code Council (http://www.iccsafe.org/Pages/default.aspx)
It's a wise investment - the electronic version is easily saved on computer and flash drive.

[John Stephenson]

I'm curious, what gave you the understanding that engineered connectors are required at all connections of deck joists (even cantilevered joists)? I teach classes so I'm always interested to learn the cause of misinformation, thanks.

FYI, IRC can be purchased here:
ICC - International Code Council (http://www.iccsafe.org/Pages/default.aspx)
It's a wise investment - the electronic version is easily saved on computer and flash drive.
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If there are any attachments to the rim, you need to add the inverted connectors. (ie: railings, stairs etc) There are often railings that often need support from the rim. If weight is going to be applied to the edge (top stair for example) the rim could loosen up without the inverted hangers.
Also it looks nicer without all those nails in the rim. :)
Inspectors are funny thangs so I just put them on and worry less.

[Jerry Peck]

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If there are any attachments to the rim, you need to add the inverted connectors. (ie: railings, stairs etc) There are often railings that often need support from the rim.

Continuing the curious aspect of the post you quoted and replied: "need to add: and "need support".

"Need" as in "is required" (and by whom) or as in "is needed for additional strenght"?