# Tension ties for deck under sunroom.



## Rick18071 (Oct 20, 2021)

I am looking at a new 20' long deck and an 20' long addition attached to each other and attached to the rear of a house. Visualize it as one 40' deck with an sunroom on the north half and just a deck on the south half. The addition is like a sunroom  but does not meet the definition of a sunroom because it doesn't have enough glass. The addition is built on the same framing as the deck. Everything complies to code except the builder installed the 2 of the  Simpson DTT12 deck tension ties 2  on the the ledger supporting the addition (south half). Should they move the 2 from under the addition (south half) to the the the deck so there are 2 tension ties on each end of the deck to comply to code and the manufacturers instructions?


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## Beniah Naylor (Oct 20, 2021)

I don't know if this helps, but if you look at this pdf from Simpson, on the first page, figure 3, all it says is that the middle two ties have to be an equal distance from the outer two.

So, I think it technically complies if you are going for the 750 lbs.


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## Beniah Naylor (Oct 20, 2021)

Beniah Naylor said:


> I don't know if this helps, but if you look at this pdf from Simpson, on the first page, figure 3, all it says is that the middle two ties have to be an equal distance from the outer two.
> 
> So, I think it technically complies if you are going for the 750 lbs.


Never mind, I think I missed the point of your post. 

I would treat the sunroom and deck combo as one unit, and figure the necessary bracing that way.


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## ADAguy (Nov 10, 2021)

Concentrated load at mid span above deck is not figured in Sinpson calc, is it?


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## Saugie53 (Nov 11, 2021)

If you are using the ICC the lateral load connection code requirement in the deck section (if I remember correctly off the top of my head it is R507.2 4) has changed over the last few code cycles. I believe the 2012 IRC was before the new 4-Piece lateral load connector came out so that code required the threaded Rod Style that was drilled through into the house they were required to have a minimum of one within 2 ft of each outside edge of the ledger, and we're rated at 1500lbs each for a total of 3000lbs of lateral tension applied for the entire deck. I could be wrong but I believe it was the 2015 code when they added the section that the new style which is the pack of four (I call them the "L-bracket" style) started being allowed to be used by code and if you look at the specs for that each one of those is rated at 750lbs which is why all four are required to be used so you get the same total of 3000lbs of tension applied to the deck. 

When I am doing residential plan reviews on decks that is one of my markups I always try to write on the plans if I don't see it mentioned because for some reason it seems contractors tend to either forget about installing them or not know what they are at all (which is kind of scary since they've been in the code for a while now). The way I have been interpreting it the lateral load devices are completely within the deck section, with the code even having a span table for open porch roof beams in a complete different section which makes me think that they are considering decks and porches two separate things. To me I have been looking at it that the whole point of the lateral load connectors are obviously to help with lateral displacement at the ledger. An open porch, screen porch, or even a sunroof, in my opinion, has more than just a deck ledger connection to the structure since it also has a roof tieing back in and due to that has more lateral strength than just a deck by itself. When I go to do inspections if I see the lateral load connectors on both the screen porch or sunroom and the deck I think even better as long as the deck by itself has the required connectors to meet the required 3000lbs (so either 2 of the threaded Rod Style or 4 of the "L-bracket" style) but if I don't see them on the screen porch, sunroom I wouldn't fail the inspection as long as the deck is meeting the minimumrequirement as I mentioned above.

That being said as an inspector I would never speak for another inspector. If it were me I would say to have your Builder move the two lateral load connectors to just the deck section but whoever the inspector you have is May interpret that requirement differently than I have mentioned above how I interpret it so they might want 2 on the deck and two on the sunroom. Your best bet would be to reach out to the building inspector or have your contractor reach out to the inspector and just ask them what they will be looking for when they come out for their inspection.


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## Glenn (Nov 11, 2021)

The lateral load connector details that got in the 2009 IRC are not required and are still not required.  This provision is one of the biggest smoke-in-mirrors, sloppy, lie of a structural design in the IRC.  They are an embarrassment that we appear stuck with for now (it's been a damn decade).  Research in 2012 shed so much important light on this subject, but has gone no where.  This is because everyone is fooled that a connection is the answer to deck lateral resistance, so no one is investing or requesting real answers.  ARGGGG!!!

This subject makes me so frustrated, and has for a decade.  I have done a ridiculous amount of research on it and many videos, On-Demand Courses and Webinars that reveal the truth behind these figures.  Yet... nothing is stronger that garbage printed right in the IRC.

Before you argue, read those sections again.  The lateral load connections are NOT REQUIRED.  They are a feel good, unproven structural connection for loads that are completely unknown but greatly handled by the ledger fasteners already.

Before you argue, watch this video.  




Before you argue, read these articles:  http://wdf.forestprod.org/Archive/23_2.pdf

After that, no need to argue at all.  You can believe whatever you want.  I'm so exhausted by this subject.


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## rogerpa (Nov 11, 2021)

Glenn:
You saved me from having to post on this. Michigan deleted R507.3.2 language and Figures.


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## Rick18071 (Nov 11, 2021)

I agree with you Glenn but the BCO which is also my boss says to require them,  even after I showed him this 
from this from the "2015 Changes to the Pennsylvania Uniform Construction Code" that the ICC wrote. 
ICC actually says the Lateral Load Connections are not required.


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## Glenn (Nov 11, 2021)

You should see what's said about them in my book, published by ICC, ha, ha!  DeckCodes.com


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## steveray (Nov 12, 2021)

I would just have it covered under the engineering for the elevated post and pier foundation engineering.....

R602.10.9 Braced wall panel support. Braced wall panel support shall be provided as follows: 1. Cantilevered floor joists complying with Section R502.3.3 shall be permitted to support braced wall panels. 2. Raised floor system post or pier foundations supporting braced wall panels shall be designed in accordance with accepted engineering practice.

Most of our sunrooms here get engineered because they can't meet prescriptive IRC...


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## Rick18071 (Nov 12, 2021)

Not sure why you would look under walls for a deck but here the state took everything out of the IRC for braced walls. This is one thing the state did we are glad of.


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## bill1952 (Nov 12, 2021)

Rick - is that by the exception added to 602.10 for detached one and two family dwellings?


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## steveray (Nov 12, 2021)

Rick18071 said:


> Not sure why you would look under walls for a deck but here the state took everything out of the IRC for braced walls. This is one thing the state did we are glad of.


You said sunroom on a deck...so it is no longer a deck, it's a room...


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## Rick18071 (Nov 12, 2021)

bill1952 said:


> Rick - is that by the exception added to 602.10 for detached one and two family dwellings?


No, the state took all of 602.10 and replaced it with the 2006 IRC section on wall bracing that only requires wall bracing in higher wind zones that we don't have in PA. So no wall bracing required at all in PA.


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## steveray (Nov 15, 2021)

2003 IRC (and before) had bracing....just wasn't spelled out as much...

R602.10 Wall brac ing. All ex te rior walls shall be braced in ac - cor dance with this section. In ad di tion, in te rior braced wall lines shall be provided in ac cor dance with Section R602.10.1.1. For build ings in Seis mic De sign Cat ego ries D1 and D2 , walls shall be con structed in ac cor dance with the ad di - tional re quire ments of R602.10.9, R602.10.11 and R602.11.


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