# New deck feeling bouncy / springy



## liljohnny (Jun 17, 2013)

kunalsikka said:


> Hi - I am getting a deck built in the backyard and not feeling very confident about the contractor. Hence tapping into the collective brain trust here for feedback.
> 
> The deck is not complete but in the section that is done, I am feeling a little bounce in the walk. The contractor has used 2x8 beams with a 9'9" span and the joist are 24" OC. The decking is 2x4 PT.
> 
> ...


Depending on the wood species, the span is likely to large for 24"OC....I would think 16"OC would likely be better suited. Having said that, 24"OC is acceptable but the deflection might be too much for you...joist spans tables do not always take acceptable deflection rates into consideration....hope that helps.


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## joecaption (Nov 30, 2011)

There can be other factors causing this, posting a picture would be a big help.
Why would use 2 X 4's? Going to get some deflection from just using them instead of 6's.


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## kunalsikka (Sep 9, 2013)

Thanks much guys for the quick response. I will post pictures soon; though most of the deck is laid out now. 

Here is one quick Q before the contractor is back this morning - he has currently screwed the 2x4s down with 2 screws on either ends and then with 1 screw at the joists in-between on alternating edges. Will instead having 2 screws at every joist help reduce the deflection?


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## joecaption (Nov 30, 2011)

Not likely to help much with deflection, but there needs to be 2, screws not one.
I would want to see blocking between the joist, joist hangers, 2 X 10 rim joist. (I build all mine with doubled up rim joist, one on the inside and one on the outside of the post)

Should be 6 X 6 posts with the rim joist sitting on a cut made into the sides of the post and double through bolted, not just nailed to the sides of the post.


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## md2lgyk (Jan 6, 2009)

Until your issue with "springiness" is resolved, I would tell the contractor to stop putting down the decking. Whatever the fix, it'll likely have to be removed. 

I would never use 2x4s for decking. Not that it's "wrong"; I just think it looks cheap. Actually, it is compared to 5/4x6, but the 5/4 looks much nicer to me.


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## joecaption (Nov 30, 2011)

Also less likely to split out on the ends when screwed down, the sealer can seal the top and sides, where as with 2's the sides will be missed, far less screws needed with wider decking, less labor since there's less boards needed.


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## jagans (Oct 21, 2012)

I can honestly say that I have NEVER seen the deck portion of a wood deck done with 2 x 4's. the decking material that I use is No. 1- 5/4 x 6 with releived edges, with supports at 16 inches on center. 

Where did you get this guy?


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## kunalsikka (Sep 9, 2013)

I am here in the northwest (Seattle) and 2x4 is the more popular size. I don't have any technical insight as to why that is the case. Guess have to do with the amount of rain and ensuring there is enough gap for the water to flow through?

Thanks all for insights. At this point I think blocking would help the issue? Any advice on straight-line or staggered?

Much appreciated!


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## robertcdf (Nov 12, 2005)

Have him install 1 more joist between each bay bringing it up to 12" O.C. This will help a bit with the springyness. 9'9" on a 2x8 @ 24" O.C. probably meets code but as you're learning it has unacceptable deflection. BTW, what does the stamped plans and permit say? Also what does the contract say? 

Did you happen to visit a deck this contractor had built before you signed a contract with him? I recommend that people visit a jobsite to see if the contractor is competent to build you the quality that you expect.


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## tony.g (Apr 15, 2012)

kunalsikka said:


> At this point I think blocking would help the issue?


Blocking helps to distribute the load a little better between the joists, but it will only reduce the deflection - and hence the bounce - marginally and will be a waste of time.

It's deeper joists you need or, as above, more of them to reduce the spacing.
Halving the spacing will reduce the load, and hence deflection, by half.


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## kwikfishron (Mar 11, 2010)

Another beam midspan would stiffen it right up and would be easy to do since you don't need deep footings with only a 5" frost depth in your area.


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## kwikfishron (Mar 11, 2010)

jagans said:


> I can honestly say that I have NEVER seen the deck portion of a wood deck done with 2 x 4's. the decking material that I use is No. 1- 5/4 x 6 with releived edges, with supports at 16 inches on center.


2X4 isn't as common as it used to be in the NW but it's still done. 5/4 however is rare 2x6 is the norm.


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## Pittsville (Jan 8, 2011)

I've not seen this mentioned yet. What size are the actual joists? Beams were mentioned and joist spacing, but not the size of the joists themselves.


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## Oso954 (Jun 23, 2012)

> only a 5" frost depth in your area.


Footings must bear on undisturbed soil minimum 12" below grade, including deck footings.

http://www.seattle.gov/dpd/publications/cam/cam303a.pdf

Page 4, item# 10 Building Construction Requirements, first bullet under Foundation


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## Clutchcargo (Mar 31, 2007)

Two pages and nobody asked what size the deck is.


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## woodworkbykirk (Sep 25, 2011)

a 2x8 beam that spans 9'9" is over spanned.. locally all deck beams must be 3ply 2x10 with no more than a 8' span. 

joists are either 12" o.c or 16" o.c , 24" would never pass


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## kunalsikka (Sep 9, 2013)

The deck is roughly 40'x20'.

I accidentally mentioned "beams" in the original thread. It's the joists that are 2x8.

Is it technically possible to layout a new beam under joists with decking on top?

Thanks all again.


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## kwikfishron (Mar 11, 2010)

kunalsikka said:


> Is it technically possible to layout a new beam under joists with decking on top?


The short answer is Yes. How high is this deck off of the ground?

Posting pictures would help.


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## woodworkbykirk (Sep 25, 2011)

kwik is right. if you have 3' or so under the deck you can do it.. its harder to move around and get things situated mind you

however adding another beam wont do anything to prevent sagging decking where you have 24 " o.c decking


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## Clutchcargo (Mar 31, 2007)

What is the span of the joists and how much is cantilevered? Is there just one beam? The 24 oc shouldn't matter as far as sagging decking because it is 2x4 planking but the deck overall sounds under structured.


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## mariaruth (Jul 25, 2013)

Also less likely to divided out on the finishes when attached down, the wax can closure the top and factors, where as with 2's the edges will be skipped, far less nails required with broader deck, less work since there's less forums required.

Should be 6 X 6 content with the rim joist seated on a cut created into the edges of the publish and dual through attached, not just nailed to the edges of the publish.


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## tony.g (Apr 15, 2012)

Aren't on-line translators great.:laughing:


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## Nailbags (Feb 1, 2012)

kunalsikka said:


> I am here in the northwest (Seattle) and 2x4 is the more popular size. I don't have any technical insight as to why that is the case. Guess have to do with the amount of rain and ensuring there is enough gap for the water to flow through?
> 
> Thanks all for insights. At this point I think blocking would help the issue? Any advice on straight-line or staggered?
> 
> Much appreciated!


I built decks and 2x4's treated will one warp buckle crack split bow cup. why? because the treated wood has a moisture content of greater then 19% as the wood dries out it wants to go back to being round like a tree. second decks and floors should be 16" OC for little defection. and 5 1/4 cedar is the norm in the pacific north west. I sure hope you have not paid this clown yet.


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## md2lgyk (Jan 6, 2009)

tony.g said:


> Aren't on-line translators great.:laughing:


Well, apparently not that one.


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## jagans (Oct 21, 2012)

mariaruth said:


> Also less likely to divided out on the finishes when attached down, the wax can closure the top and factors, where as with 2's the edges will be skipped, far less nails required with broader deck, less work since there's less forums required.
> 
> Should be 6 X 6 content with the rim joist seated on a cut created into the edges of the publish and dual through attached, not just nailed to the edges of the publish.


Thanks man, I always wanted to know how to do that, but could never find anyone to properly explain it. I finally get it!


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## AndyGump (Sep 26, 2010)

mariaruth said:


> Also less likely to divided out on the finishes when attached down, the wax can closure the top and factors, where as with 2's the edges will be skipped, far less nails required with broader deck, less work since there's less forums required.
> 
> Should be 6 X 6 content with the rim joist seated on a cut created into the edges of the publish and dual through attached, not just nailed to the edges of the publish.



Quite more likely that I would be pleased that for you to not publish in the very unlikely and unqualified event of your demise. 
So please to go urinate up a rope. :thumbsup:


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