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The simple solution is to add a beam somewhere between 8ft and 12ft from the house. Leave the original post as is.
You know what … you can minimize the visual impact of a new beam with some labor and joist hangers. Rather than simply adding the new beam under the joists, cut a 3” wide gap in all the joists and push the beam up tight under the deck boards. Hang the existing joists off the sides of the new beam. You will “hide” 8” of the new beam.
 

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. Depending on where you live you could have a substantial snow load with drifting or no snow at all.
I wonder if the 50 psf snow load would be offset by zero people load. Maybe not … folks crazy enough to live where you get that much snow probably don’t hesitate to go out on the deck in all weather.
 

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Discussion Starter · #63 ·
did you have it built or just bought the house ?
Bought the house with it in 2017. I’m irritated that it didn’t come up in the inspection. I think the deck was installed in 2011 or 2012.

I was looking at span tables in the IRC and spans are dependent on species (PT-SYP #2?), spacing, live load and dead load. At my NY house we have a 50 PSF ground snow load which equals a 35 PSF roof snow load. Depending on where you live you could have a substantial snow load with drifting or no snow at all.
I live in Nashville, TN. We do not see much snow. More likely to get ice. However we did have a 2 day storm this past winter that brought, 2 inches of sleet followed by 5 inches of snow.
 

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[
Bought the house with it in 2017. I’m irritated that it didn’t come up in the inspection. I think the deck was installed in 2011 or 2012.



I live in Nashville, TN. We do not see much snow. More likely to get ice. However we did have a 2 day storm this past winter that brought, 2 inches of sleet followed by 5 inches of snow.
What are you after, making it safer or making it up to code?
We can all agree the joists are over spanned and the bean is extremely undersized.
But it has been there and used for 8 years and it is at an age with wear and tear it may be getting closer to dangerous.
We haven't talked about the joists, 8 years old if they do not have protective tape on top, they may have some rot in the top inch making them weaker every year.
 

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I live in Nashville, TN. We do not see much snow. More likely to get ice. However we did have a 2 day storm this past winter that brought, 2 inches of sleet followed by 5 inches of snow.
Good, light snow load is in your favor.
 

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Discussion Starter · #66 ·
What are you after, making it safer or making it up to code?
We can all agree the joists are over spanned and the bean is extremely undersized.
But it has been there and used for 8 years and it is at an age with wear and tear it may be getting closer to dangerous.
We haven't talked about the joists, 8 years old if they do not have protective tape on top, they may have some rot in the top inch making them weaker every year.
Id like to make it safer. The joist were not taped. I’ve replaced 5 deck boards and didn’t see any rot. And I don’t see any rot looking up at the joist.
 

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Id like to make it safer. The joist were not taped. I’ve replaced 5 deck boards and didn’t see any rot. And I don’t see any rot looking up at the joist.
So the choices you have as I see them.
1. Just fix the beam issue with a new beam next to the posts with 4x6 below it.
2. put a new beam 2 ft closer to the house solving the beam problem and making the joist span 20% better than it was.
3. Add the beam like in #1 and add another beam at 10 to 12 feet from the house which would bring it to code.
 

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Y’all are nuts. You’re looking for the cheap easy solution because you don’t like the facts. No matter how much you want the existing 2x8 joists to work … it won’t work with the existing column locations. The only way to make 2x8 work is to shorten the span, but even then it won’t make 16 ft overall even with cantilever. You need two rows of columns, or larger joists.

View attachment 658519
Doubling up the 2x8, giving you the equivalent of a 2x8 every 8", gets you strength fairly close to that of 2x10's at 12". Based on that table, sistering the 2x8's makes the joists adequate for the 16' span.
 

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If I am seeing it correctly, the outer end looks like it has 5-2x8s supported by 1-2x8. Half of those 5 is supported by the house, the other half by the rim joist. I would have them supported by 3 on the outer end. And the posts are not under the supported member. It could have a punching shear failure like the pool deck on the high rise in FL.
Without getting into a bunch of engineering mumbo jumbo, to make the rim joist/beam be able to carry the same uniform load as the sistered 2x8 joists, you would need to triple the 2x8 rim, or replace it with double 2x10's. Because of its much higher allowable stress, a single 1.75x9.5 LVL would also have adequate capacity. I don't know if exterior rated LVL's are available where you're at (or anywhere), though.
 

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Without getting into a bunch of engineering mumbo jumbo, to make the rim joist/beam be able to carry the same uniform load as the sistered 2x8 joists, you would need to triple the 2x8 rim, or replace it with double 2x10's. Because of its much higher allowable stress, a single 1.75x9.5 LVL would also have adequate capacity. I don't know if exterior rated LVL's are available where you're at (or anywhere), though.
I have never seen LVL used in the weather but I did see where one outfit was selling treated ones.
 

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Doubling up the 2x8, giving you the equivalent of a 2x8 every 8", gets you strength fairly close to that of 2x10's at 12". Based on that table, sistering the 2x8's makes the joists adequate for the 16' span.
The problem with that statement is that published joist tables (to my knowledge) only go down to 12” oc. So if you want a different spacing and you want to pass inspection, you would have to get the design approved by an engineer.
 

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The problem with that statement is that published joist tables (to my knowledge) only go down to 12” oc. So if you want a different spacing and you want to pass inspection, you would have to get the design approved by an engineer.
Yes, I suppose if it has to pass inspection, he may need an engineer licensed in his state.
 

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You could put beams 2 foot in from house and deck edges leaving 12 foot span. That would also leave 12 foot space that is stil full height under deck. Use lateral ties to the house or just leave current bolts. That would give you a freestanding deck attached to the house, but the house side beam would block the view from the window.
 

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Little bounce can be lived with. Front single joist holding all the floor joists has a middle post which helps. You can add another on the opposite side of the posts. Not ideal and not to current codes but lots of it done in past and used as such. Your deck will not fall because of it but it will have less life. In nj and standard deck may be used as much as 40 years with all lumber cracking and loose joints but depends on user's sensibilities. Newer decks with copper treatments may not last as long as well as shorter fastener/hardware lives because of the corrosion. You can add corner braces to reinforce the deck to post movements.
Use it for 20 and rebuild. Since you have the inside open, replace the carriage bolts for heck of it with double dipped bolts against corrosion if you're not sure how those bolts were treated against corrosion. Next deck, add flashing and let it into the brick joint. Ledger should be tight to the house and not on a veneer brick but the fact is it is standing and maybe the bricks aren't standing against air. Posts are buried in ground as well. 4x4 treated fence post buried in the ground has a max life of about 20 years, as a kind of reference. Surrounded by concrete, it may rot litlle faster.
Lots of maybe's, so better to think shorter life and future replacement. For 16' deck, beam can be closer to the house and some of the floor joists cantilevered. 2x10, I think, is rated up to 14' and deck cantilivers can be up to 24".
 
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