Knee bracing alternatives for freestanding Deck

Reply

  #1  
Old 09-17-18, 10:38 PM
L
Member
Thread Starter
Join Date: Apr 2018
Location: United States
Posts: 13
Received 0 Votes on 0 Posts
Knee bracing alternatives for freestanding Deck

I am getting closer to my final plans for my future second story deck. My second story of my house has a one foot cantilever on the back side of my house. By code I can not do a ledger attachment, so I am building as a freestanding deck. I am wondering if there are any alternatives to the knee / cross bracing instead of what I have designed (see pics). Maybe something heavy duty like a Simpson CC46 post cap. I would like to do retractable screens in the future like the last picture, so I have designed the crossbracing to not interfere. If any one knows how I can eliminate some of the bracing and still be able to get inspectors approval, please let me know. Any other suggestions and opinions are welcomed. Just FYI I am planning to use Lockdry Aluminum decking to keep the patio area below dry and I have yet to work on the railings.
 
Attached Images     
Sponsored Links
  #2  
Old 09-18-18, 06:01 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 23,981
Received 681 Votes on 628 Posts
I would discuss your plans with your building inspectors first. They are important to keep in the loop if you are doing anything non-standard.

The Simpson caps you mentioned might be good enough. You will have to look into the documentation and see if they can provide the needed support.

Depending on the height of your deck using 4x4 for the posts could be a problem, especially if you don't have diagonal bracing extending far below. 4x4 are only so rigid. You might have a good steel bracket above but the wood in between can still flex and wiggle like a noodle. You might consider going up to 6x6 for the posts. You don't need it for bearing the load but it could help firm up the deck.

The other option is expensive. You'll need a structural Engineer. They can design steel brackets (that would have to be custom fabricated) to provide the strength and stiffness you need. With a professional Engineer's stamp on your plans your building inspectors will largely be out of the loop regarding the design and will largely focus on whether or not you constructed the deck to the Engineer's plans.
 
  #3  
Old 09-18-18, 07:58 AM
L
Member
Thread Starter
Join Date: Apr 2018
Location: United States
Posts: 13
Received 0 Votes on 0 Posts
The posts are 6x6, and the beams are triple 2x12s. The building inspectors in my county are not helpful. They will mark something incorrect, but refuse to suggest or tell me how to fix the issue. What is the best way to enlist a engineer? The ones I have found around here are all part of larger firms and would not work on plans that their company is not building. Has any one got experience with reducing bracing on their projects?
 
  #4  
Old 09-25-18, 10:54 PM
L
Member
Thread Starter
Join Date: Apr 2018
Location: United States
Posts: 13
Received 0 Votes on 0 Posts
Bump to see if anyone has any comments or suggestions before I proceed. FYI I am planning on using LockDry Aluminum Decking as seem in this pic. But have not designed the railing for the top side yet.
 
Attached Images  
  #5  
Old 09-26-18, 12:54 AM
czizzi's Avatar
Member
Join Date: Jul 2007
Location: USA
Posts: 7,388
Received 14 Votes on 12 Posts
Is it just an anomoly in your pictures, but is shows your deck under the cantilever which would make a ledger direct to the house possible. This would eliminate any sway front to back. You would only have to worry about sway left to right. Even at that, you may not need bracing at every post, just the corners may provide enough stability.

Not familiar with aluminum drylock decking. Perhaps you can provide a link to the product. My concerns are that the decking will not provide any lateral support as the aluminum decking may not be structural in any way.
 
  #6  
Old 09-26-18, 01:58 PM
L
Member
Thread Starter
Join Date: Apr 2018
Location: United States
Posts: 13
Received 0 Votes on 0 Posts
Yes the deck is under the cantilever. I believe attaching may not be possible because it would only be able to attach to one or two horizontal 2x4s and the wall studs they are resting on the top of. I don't think I have ever seen ledgers not attached to a floor joist. Also since my house is real stucco, code dictates it must be removed before ledger is attached. But thanks for the suggestion, I had not considered still attaching once I knew I could not attach it to cantilever.

Here is the lockdry info and specs:
https://www.nexaninc.com/products/decking/lockdry-waterproof-decking/lockdry-downloads
 
  #7  
Old 09-26-18, 04:23 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 26,198
Received 714 Votes on 661 Posts
You can have a structural engineer draw you up some steel t-brackets and corner brackets to take the place of your gussets. They will need to be bolted with 1/2" bolts. Hot dipped galvanized brackets that are powder coated black will look best and last longest.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: