I just did a deck with a 16 foot span with 2x10 joists 16 on center and im lookin at it, and the joists sag. 16 foot is ok with local code but the thing sags like 1/2 inch in the center. I did not install bridging blocks because I wanted to eliminate the sqeak factor. Do you think thats why it sagged or do you always have to oversize preasure treated lumber because it is so wet and floppy?
floor joist sizing
bluebird5
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I just did a deck with a 16 foot span with 2x10 joists 16 on center and im lookin at it, and the joists sag. 16 foot is ok with local code but the thing sags like 1/2 inch in the center. I did not install bridging blocks because I wanted to eliminate the sqeak factor. Do you think thats why it sagged or do you always have to oversize preasure treated lumber because it is so wet and floppy?
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I come up with 14'4" at L/480 40/10
This us fir thou
I would never go 16 ft with a 2x10. I dont go over 12 with 2x10, everything over 12 gets another beam. I like my decks to be as solid as my floors if not more so. People congregate on decks in groups and a little over building makes it not feel like a trampoline when 8 adults are siting/ standing in a 7 ft circle.
This us fir thou
I would never go 16 ft with a 2x10. I dont go over 12 with 2x10, everything over 12 gets another beam. I like my decks to be as solid as my floors if not more so. People congregate on decks in groups and a little over building makes it not feel like a trampoline when 8 adults are siting/ standing in a 7 ft circle.
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Crown would not help this at all.
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What kind of PT are you using.
Bluebird, you are all over this board with plumbing, roofing, carpentry & framing questions.
I admire that you are ambitious....but learn a trade & learn it well.:thumbsup:
Become a real pro. I believe you recently had a flashing question.
To succeed you must rise above the norm...acquire a reputation as a top drawer all first class kind of guy. No BS with reusing flashings or what ever...All top notch first class stuff. When you acquire that rep you will have people that demand & want that type of guy. It takes experience & knowledge, but you have to start to get there.
I admire that you are ambitious....but learn a trade & learn it well.:thumbsup:
Become a real pro. I believe you recently had a flashing question.
To succeed you must rise above the norm...acquire a reputation as a top drawer all first class kind of guy. No BS with reusing flashings or what ever...All top notch first class stuff. When you acquire that rep you will have people that demand & want that type of guy. It takes experience & knowledge, but you have to start to get there.
All wood is not created equally. Take morningwood for example...
The span chart is probably for fir/larch/hemlock. Your pressure treated stuff is probably southern yellow pine.
12" spacing is a good thing. It will help. Same with solid blocking. Don't forget you can cantilever over the beam by 3x the joist width. This will help also.
Griz is right about the quality work. Hopefully you will still be able to walk by the time it pays off.
The span chart is probably for fir/larch/hemlock. Your pressure treated stuff is probably southern yellow pine.
12" spacing is a good thing. It will help. Same with solid blocking. Don't forget you can cantilever over the beam by 3x the joist width. This will help also.
Griz is right about the quality work. Hopefully you will still be able to walk by the time it pays off.
Mark is correct.
If you get closer to the limit of your span it will start to bounce.
Depending on the wood type looks like you are very close to that.
Add a beam in the center and it will be solid.
Clemens
www.finedecks.com
If you get closer to the limit of your span it will start to bounce.
Depending on the wood type looks like you are very close to that.
Add a beam in the center and it will be solid.
Clemens
www.finedecks.com
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5,672 Posts
Error on my behalf...in '93 if I remember correct.
9 1/2" TJI15, continuous span, 15'-6" both sides of bearing wall, 24" o.c., 5/8" T&G OSB...met span tables of the day...worst floor I ever did.
I gave the customer a 5/8" drywall ceiling in the basement to reduce the bouncing effect, but never again would I follow that table to the max. spans allowed.
We are all here to learn from each other.
Perhaps as a good measure you go back and install another joist between, 8" o.c. or get a beam running down the center.
9 1/2" TJI15, continuous span, 15'-6" both sides of bearing wall, 24" o.c., 5/8" T&G OSB...met span tables of the day...worst floor I ever did.
I gave the customer a 5/8" drywall ceiling in the basement to reduce the bouncing effect, but never again would I follow that table to the max. spans allowed.
We are all here to learn from each other.
Perhaps as a good measure you go back and install another joist between, 8" o.c. or get a beam running down the center.
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My deck has a 14' span and I built it with double 2"x10" on 12" centers. I also have triple blocking course (solid).
The deck is topped with 5/8" sheathing and will get another 1/2" layer, 1/4" Hardiboard then Noble Companies Noble Deck.
The deflection rating of my deck is L/1120 or something like that plus what ever gain I get from the 1/2" ply and blocking.
Some jobs here in Vancouver I jump on and the bounce factor is insane. When I can bounce it with so much ease and the builder doesn't want to upgrade - we go bye bye. :no:
JW
The deck is topped with 5/8" sheathing and will get another 1/2" layer, 1/4" Hardiboard then Noble Companies Noble Deck.
The deflection rating of my deck is L/1120 or something like that plus what ever gain I get from the 1/2" ply and blocking.
Some jobs here in Vancouver I jump on and the bounce factor is insane. When I can bounce it with so much ease and the builder doesn't want to upgrade - we go bye bye. :no:
JW
The quality of wood we get around here, crown makes a big difference. :laughing::sad:
Anyone who builds decks should get the free download of DCA6-09, from www.awc.org, also known as the prescriptive wood deck construction guide. According to the span tables contained in it, 2x10 at 16" o.c. is allowed a span of 13'7". It would appear that you are a bit overextended at 16'. And midspan blocking is always a good idea. Adding a beam in the center, as someone suggested, is probably your best best.
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What I was implying is that even if they had a 1 inch crown up it still is not going to help this situation.
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You have to use a span table with a deflection table. This will tell you what kind of deflection your going to get.
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This is L/180 at 40/10
I think my daughters trampoline has less bounce then your deck.
The Maximum Horizontal Span is:
14 ft. 4 in.
with a minimum bearing length of 0.84 in.
required at each end of the member.
Property Value
Species Southern Pine
Grade No. 2
Size 2x10
Modulus of Elasticity (E) 1368000 psi
Bending Strength (Fb) 966 psi
Bearing Strength (Fcp) 378.55 psi
Shear Strength (Fv) 135.8 psi
I think my daughters trampoline has less bounce then your deck.
The Maximum Horizontal Span is:
14 ft. 4 in.
with a minimum bearing length of 0.84 in.
required at each end of the member.
Property Value
Species Southern Pine
Grade No. 2
Size 2x10
Modulus of Elasticity (E) 1368000 psi
Bending Strength (Fb) 966 psi
Bearing Strength (Fcp) 378.55 psi
Shear Strength (Fv) 135.8 psi
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