joist spacing for deck


  #1  
Old 09-11-23, 10:53 PM
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joist spacing for deck

Hello all,
I have a balcony as pictured below. It's a pain to repaint it every few years. I would like to replace the floor with composite decking. Hover the joists below are spaced 20" apart. Everything I found says 16" apart max.
Are there products you know of that I could use? Or another way to build proper support?
Currently, it has 2x8 wooden boards and there is some rot on few of them near the perimeter.

Thank much

 
  #2  
Old 09-12-23, 03:17 AM
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the joists below are spaced 20" apart.
Is that between the joists? Center of one to center of the next is probably 24".
That would make for easy lay pattern of flooring.

Some people use 16" some use 24" depending on the plans/project.
 
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Old 09-12-23, 03:40 AM
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Follow the composite manufacturer's installation instructions for the best result. You have some wiggle room since the floor joists are thicker than normal deck floor joists which are 1 1/2 inches thick. Since the deck joists extend beyond the railing, you could attach composite samples and check its response.
 
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Old 09-12-23, 05:27 AM
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I assume your joists are on 19.2" spacing. Composite decking is not structural so it can't span distances as well as structural wood. I would check different brands of composite decking. I think there are some that have internal reinforcement and can span greater distances.
 
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Old 09-12-23, 09:50 AM
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Thanks all. After measuring again, it turned out the gaps between the joists are rather irregular. They vary from 20" to 23". That is from edge to edge. Center to center would be 25.5" to 28.5" given the joists are 5.5" thick.
Most products I found say 12" for joist support. Very few say 16".
 
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Old 09-12-23, 10:41 AM
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Check out Wear Deck from Owens Corning. They state it can span 24" ctr to ctr. Also look at aluminum decking which can span longer distances based on load.
 
  #7  
Old 09-12-23, 12:52 PM
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Another possibility would be to bridge between the existing joists and add in another joist between the existing.

The problem I see with this is to come up with a design that is visually pleasing.

 
 

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