DIY Home Improvement Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
104 Posts
Discussion Starter #1 (Edited)
Hey I’m in the process of replacing deck boards. After taking a look at the structure it seems like the deck was built with:

2-2x6 joist spanning 9 feet.

They doubled up the 2x6 joist but they have them at 24”OC

What would you guys do to remedy the situation?

A. I always do mine 16OC and
B. I don’t double my joist....

If I remove all the joist I’ll risk damaging everything I’m afraid. Should I just add an extra joist In Between and just make it 12OC for some overkill? How would you guys go about it?


Sent from my iPhone using Tapatalk
 

·
Guapo
Joined
·
5,940 Posts
You probably don't have to touch the joists. If you're not a politician, don't look for a solution to a non existent problem. Structure starts from the bottom. First look at the posts & the footings. Are there footings. Has the deck shifted or sunk?
 

·
Registered
Joined
·
104 Posts
Discussion Starter #4
Deck is sitting on brick pillars. The deck is actually plenty supported in terms of post wise....

I’m using 5/4 SYP PT deck boards


Sent from my iPhone using Tapatalk
 

·
Guapo
Joined
·
5,940 Posts
Brick pillars don't count as footings. If you aren't going to correct that, don't correct anything else. Adding joists will add weight to the structure.
 

·
Registered
Joined
·
104 Posts
Discussion Starter #6
It’s sitting on brick pillars over concrete with additional footings. Like I said. It’s plenty supported from the bottom. There’s zero worry about sinking. I’m more worried about the joist and the bounce


Sent from my iPhone using Tapatalk
 

·
retired framer
Joined
·
39,013 Posts
You may find more trouble when you remove the old decking, double joists tend to hold water on top you may find some rot there. What is the decking now, how does it do spanning the 24 inches ? If you put one between can you do that with 2x8?
 

·
Contractor/Engineer
Joined
·
599 Posts
Depending on the square footage - I'd simply put additional 2X6 at 12" o.c. between the existing sistered joists.

Yes, it will be a little overkill, but you don't have remove anything - just add hangers or ledger board at each end. Might be tight to nail...

And, if you're on 12" o.c. you could move to Trex/other.

If the existing joists are in good condition and dry - you should waterproof the tops (product of your choice).
 

·
Registered
Joined
·
104 Posts
Discussion Starter #9
I like the idea of putting a 2x8...

There’s actually no rot on the joist being as it has a roof over the deck. Everything looked fine.

I’m not sure how it feels currently because instead of them having the deck boards running on top of the joists... they decided to run it parallel with the joist and the boards are all on top of the braces.... :/


Sent from my iPhone using Tapatalk
 

·
retired framer
Joined
·
39,013 Posts
I like the idea of putting a 2x8...

There’s actually no rot on the joist being as it has a roof over the deck. Everything looked fine.

I’m not sure how it feels currently because instead of them having the deck boards running on top of the joists... they decided to run it parallel with the joist and the boards are all on top of the braces.... :/


Sent from my iPhone using Tapatalk
So that would be strapping, and how far apart is the strapping.
 

·
Hammered Thumb
Joined
·
2,829 Posts
Not what I pictured from the words. Much worse.

I think from the pic you have one (2)2x6x9' BEAM with single [email protected]"o.c. STRINGERS spanning about 5' on either side of this BEAM? Then each end of the BEAM mounts midpoint on a (2)2x6 GIRDER which then rests on the posts?

Spacing could be done at 24"o.c, and you could use beam/girder method. Except here each instance is all undersized. I would think about replacing more than the decking.
 

·
Registered
Joined
·
221 Posts
No wonder it's bouncy. I sure wouldn't want that attached to my house the way it's built. As 3ontree pointed out, the outside 2x6(8?) girder is holding the load that the beam is carrying. It's an overly complicated but weak design that creates a lynchpin failure point.
Like others, my choice would be to rebuild the framing as well.
 

·
Registered
Joined
·
104 Posts
Discussion Starter #16 (Edited)
Yeah I’m going to have to redo the whole structure. After uncovering everything it seems like I’m at a lost at why they did what they did.

I’ll save what I can by not tearing it down completely and just reorienting the beams and joist configuration.

Keep the outside beam. Turning the center beams into joist. Add more sistered 2x6 joists so they are 16OC




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
6,399 Posts
Not sure I see anything there that can be salvaged. Looks like that outside beam has splices all over it. I don't see much on how the ledger board is mounted, but its mounted to what is likely just brick veneer anyways.
 

·
Hammered Thumb
Joined
·
2,829 Posts
Yeah I’m going to have to redo the whole structure. After uncovering everything it seems like I’m at a lost at why they did what they did
These 4 pics tell a better story. I'll describe what I think I see from them (can't zoom in though) and let you go from there, but glad you're at least rethinking what to do.

I've come across many houses that extend and cantilever the interior floor joists outside for a porch/deck, but usually around 3-4 feet. Sometimes they've had brick piers, but those are mostly for looks. It's obviously hard to replace them when there's rot, and they will rot being untreated.

Here it looks like they did a version of that. Is the interior joist framing [email protected]"o.c.? You can see the holes in the brick every 24" (pic4). Like they extended the 2x6 out, except at 10' it's too long for a cantilever, so they may be a separate 2x6 resting on the interior wall frame. At some point I'd say there was rot, so they cut off/removed some, and doubled up the remaining ones to take the load (pic3) and cover minor rot. Then they nailed the stringers and ledger board between these remaining doubled-up joists.

So here are some issues I spot:
1. Brick (used as veneer) is not structural. Both the piers and exterior wall.
2. The brick piers do not look to be attached to the beam.
3. The ledger board looks to be only nailed between the double joists.
4. The double joist "sister" does not extend to bearing (pic3), which makes it just a single joist structurally.
5. Adding [email protected]"o.c. may not meet load reqmts at 10' long.
6. The (2)2x6 beam resting on the piers is already undersized, especially when planning on adding more 2x6 joists.
7. The 4x4 posts holding up the roof are not positioned over the piers (pic2), accentuating the inadequacy of the beam. They are also notched reducing the amount of effective load transfer.
8. The roof: If the rafters are continuous from the ridge to the 4x4 posts, all of the structure at the front of the porch is probably inadequate. If the rafters are just a tack-on "shed" bearing on the house wall to the 4x4 posts, it all still probably needs re-thought.
 
1 - 19 of 19 Posts
Top