DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   deck sway (http://www.diychatroom.com/f19/deck-sway-52305/)

redroc25 09-04-2009 10:19 AM

deck sway
 
I am building a 13x16 deck attached to the house and based on slope of yard, goes from appr 4.5'-6' over ground. I am using 2x10 wood. my question is on the deck "Sway" that is parallel to the house- Any recommondations to reduce the sway? I was told to use 4x4 posts. Used simpson ties/post braces, etc.

All wood has been purchased and the frame has been installed. I have not installed the deck boards yet, but the frame iteslf seems to sway too much at this point.

Thanks for your help.
Adam

Scuba_Dave 09-04-2009 10:23 AM

Do you have a picture?
How high off the ground is the end of the deck, only the ~6' you mentioned?

concretemasonry 09-04-2009 10:42 AM

So far you have not mentioned anything that would eliminate the "sway" of the outer frames. Do you have any drawings or photos?

The decking can stiffen it up, depending on the direction it is laid. You can also install horizontal diagonal bracing to the bottom of the joists or vertical diagonals between the posts and the outside girder/beam. Nailed joints and 90% of the metal connectors do not provide connections that cannot rotate some - especially with a bunch of people moving around on the 13x16 deck.

Who designed the deck and who got the permit?

I assume it is the non-preferred ledger method of connection to the house and hope that you used through bolts instead of lags and installed flashing under your moisture barrier. It may be too late for that now.

Dick

redroc25 09-05-2009 10:21 AM

responses to your q's
 
I designed the deck with both HD and Loews, both were relatively the same design. I however incorrectly listed the size of the deck on my post, the deck that sways is 16x20 (sorry, had two built the other one is fine!).

top height off of the ground is 6'. the ledger is bolted to house with bolts (Not bolted through), but this isnt the sway problem! It sways at the 20 foot away from the house in the same direction of the house (ie parrallel).

The deck boards will run in the same direction the deck is currently swaying (again parrallel).

Thanks again.

Adam

JonM 09-05-2009 11:48 AM

The floorboards will take most of the sway out...but also use 2 1/2 foot diagonals (2 per post) lagged in with 31/2" lags

Scuba_Dave 09-05-2009 11:51 AM

Take a look at this deck/pavillion thread with the cross bracing at the posts

http://www.diychatroom.com/f19/pavil...ld-help-52230/

What do you have for posts & framing structure?
How far apart, beam sizes...etc
Without some idea of how the deck is built its hard to give a recommendation

Aggie67 09-05-2009 11:54 AM

Generally accepted good practice will include the use of braces, blocking, and properly sized piers/posts. If you haven't downloaded the AWC's Prescriptive Residential Wood Deck Construction Guide (it's free), please do so. Read that, and if you have any questions, please post back.

Please note that the design guide recommends 6x6 posts, so you're already behind the 8 ball in my opinion. And depending on the span you have and wood species, 2x10 joists may not cut it.

concretemasonry 09-05-2009 12:15 PM

If you find it sways too much, you will have to install diagonal braces in the "frame" that is parallel to the house.

Most metal nailed corner braces do not really provide any real resistance to rotation. They are strong and reliable in other ways as they are intended to be.

Dick

redroc25 09-06-2009 09:44 AM

answers
 
Ok, so I am going to try the braces on the posts at 45 degree angles to see if that helps....in the mean time, to answer some of your questions, in an effort to help me:

1- deck is attached to house with anchor bolts
2- deck is 16 x 20, using 2x10 joists, spaced appr 16" on center
3- ledger boards are double 2x10's at approx 11' and 19'marks. From what I have read, this is leaving an allowable spacing using 2x10 joists.
4- I have used 4x4 posts, on concrete footers 36" deep (as needed for permit).
5- Designed deck using Loews/HD computer program, both stated 4x4 would be acceptable.
6- 3 posts on each ledger at the 11 and 19' marks (one at each edge, and then in the middle), used post brackets on the cement/post and then again used brackets to hold the ledgers on the posts (ledgers are resting on the posts utilizing the brackets).
7- I added blocks at approx the 5' mark (so then there is now lateral support at the 5' and 11' (where ledger exists) and again at approx 15' as well.
8-used simpson ties for each connection to a ledger board at each crossing, used corner brackets too from simpson.
9- deck is attached to the house, where it is appr 5' off the ground, at the edge 20 feet out, the deck is 6' off the ground due to the slope of my yard.
10-i will be using composite deck boards after the inspector approves the framing!

thanks, I think that describes all of the deck and again thanks for your help in trying to solve my sway problem!
adam

Joe Carola 09-06-2009 11:47 AM

Quote:

Originally Posted by redroc25 (Post 324383)
Ok, so I am going to try the braces on the posts at 45 degree angles to see if that helps....in the mean time, to answer some of your questions, in an effort to help me:

1- deck is attached to house with anchor bolts
2- deck is 16 x 20, using 2x10 joists, spaced appr 16" on center
3- ledger boards are double 2x10's at approx 11' and 19'marks. From what I have read, this is leaving an allowable spacing using 2x10 joists.
4- I have used 4x4 posts, on concrete footers 36" deep (as needed for permit).
5- Designed deck using Loews/HD computer program, both stated 4x4 would be acceptable.
6- 3 posts on each ledger at the 11 and 19' marks (one at each edge, and then in the middle), used post brackets on the cement/post and then again used brackets to hold the ledgers on the posts (ledgers are resting on the posts utilizing the brackets).
7- I added blocks at approx the 5' mark (so then there is now lateral support at the 5' and 11' (where ledger exists) and again at approx 15' as well.
8-used simpson ties for each connection to a ledger board at each crossing, used corner brackets too from simpson.
9- deck is attached to the house, where it is appr 5' off the ground, at the edge 20 feet out, the deck is 6' off the ground due to the slope of my yard.
10-i will be using composite deck boards after the inspector approves the framing!

thanks, I think that describes all of the deck and again thanks for your help in trying to solve my sway problem!
adam

Install the decking FIRST and then see if it still sways. No need for anything else until you install the decking. Every single deck sways a little until it has the decking.

Gary in WA 09-06-2009 02:19 PM

"1- deck is attached to house with anchor bolts Through bolts w. nuts and flat washers, all dipped galv. Table #5, 14" through 1/2" ply and 1-1/8" engineered rim = 14" o.c. with 1-1/2" solid rim = 29" o.c.
2- deck is 16 x 20, using 2x10 joists, spaced appr 16" on center May want to reduce to 14" or so.
3- ledger boards are double 2x10's at approx 11' and 19'marks. From what I have read, this is leaving an allowable spacing using 2x10 joists. Built beams, install sticky window wrap on top edges, by Grace. Seals nail holes.
4- I have used 4x4 posts, on concrete footers 36" deep (as needed for permit). Use sono's on a footing, 15"x6" - if span of beam is reduced, to get post out of ground and protect against frost heave with gravel: http://books.google.com/books?id=1gg...num=3#PPA31,M1 http://rockproducts.com/mag/rock_agg...prevent_frost/ http://www.sustland.umn.edu/implemen..._footings.html
5- Designed deck using Loews/HD computer program, both stated 4x4 would be acceptable. Not per 2006 code, as Aggie said: http://www.awc.org/Publications/DCA/DCA6/DCA6.pdf
6- 3 posts on each ledger at the 11 and 19' marks (one at each edge, and then in the middle), used post brackets on the cement/post and then again used brackets to hold the ledgers on the posts (ledgers are resting on the posts utilizing the brackets). Over span as per code = 6'2" figuring 50# sq. ft.
7- I added blocks at approx the 5' mark (so then there is now lateral support at the 5' and 11' (where ledger exists) and again at approx 15' as well." Blocking, same size as joist, required at all bearing to prevent rotation.

Let's see some finished pics when done! Hope this helps....
Be safe, G

redroc25 09-13-2009 02:46 PM

added 6x6's....
 
I added two 6x6 posts to the end the deck was swaying and man what a difference!!

Thanks for all your help and advice, my deck sway problem is now fixed. Based on the comments about adding the deck boards, now the minimal movement should clearly be stopped when I add the deck this week@!!:thumbup:


All times are GMT -5. The time now is 01:16 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved