Double 2x4s for Deck Joists.


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Old 05-12-19, 12:54 PM
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Double 2x4s for Deck Joists.

We currently have a 2-story deck that extends the length of the house and extends 8' out.
I'd like to extend it to 16'.
There is a deck on the top story, and on the story below.
The house is on a hill, with the top story the entry floor.
It currently has (basically) single 2x6 beams.

Ideally I would like to have the supporting beams 16' out from the house so that the bottom deck does not have beams in the center of it, and at the end.
I have an opportunity to purchase 100 2x4x16 at a very nice price, and am wondering if doubling up on the 2x4's will suffice?

If I have to keep the supporting beams at 8', then another at 16', I can do that & live with beams splitting up the lower deck.
Also, if I do that (beams at 8' & 16') I can use the 8' 2x6s from one of the decks and use them for the other deck, right?

Thanks in advance for any help.
 
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Old 05-12-19, 01:51 PM
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2x4's are never used as structural components, for what you are considering I would strongly suggest you get an engineer involved to calculate the loads!
 
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Old 05-12-19, 03:45 PM
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I have an opportunity to purchase 100 2x4x16 at a very nice price, and am wondering if doubling up on the 2x4's will suffice?
Is this a joke? If not, its the worst idea ever. You might Google DCA6 deck guide, it's a free download and educate yourself on how decks are properly built.

A single 2x6 is not a beam. Sounds like you need to start over, sorry to say.
 
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Old 05-12-19, 04:39 PM
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You could use the 2 X 4's as decking if they're a really good price, but not for structure. The deck you are describing is a complex structure. Should it collapse it could cause a fatality.
 
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Old 05-12-19, 05:11 PM
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XSleeper, the 2x4s would be for joists, NOT for the supporting beams.
They would replace the SINGLE 2x6s that are currently used.
From what I am hearing is that 2x4's doubled up are not as strong as a single 2x6.

That's cool, that is why I am asking.
 
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Old 05-12-19, 05:31 PM
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the 2x4s would be for joists,
exactly. That's a no. Capital NO.
 
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Old 05-12-19, 11:04 PM
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2x4s have very little ability to carry a load; they are simply not up to the task.

As mentioned earlier, your concept is complex enough you probably should have an engineer involved.
 
 

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