Uneven joists for composite decking

Reply

  #1  
Old 05-02-18, 02:23 PM
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Uneven joists for composite decking

Building my first deck. Just wondering what the tolerance is for variations in joist heights. I'm just trying to avoid the appearance of a wavy deck. Should I be worried about 1/8", 3/16", 1/4"? Where do you guys draw the line?
 
Sponsored Links
  #2  
Old 05-02-18, 03:23 PM
czizzi's Avatar
Forum Topic Moderator
Join Date: Jul 2007
Location: USA
Posts: 7,376
Received 9 Votes on 7 Posts
Some composites are more likely to show waves than others. I would shoot for no more that 1/8".

Are the joists set on a ledger, or on joist hangers. Either way, you either shim the joists or remove small bit to even them out.

Some composites recommend joists that are 12" on center so double check. What brand of composite are you using?
 
  #3  
Old 05-02-18, 04:51 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,315
Received 214 Votes on 199 Posts
Always a good idea to get them as flat as possible. I generally will power plane joists to make them straight.

Problem is with time and weather the deck usually warps a little anyway. Some guys like to use crowned joists on decks... (creates a prestressed deck) if that's the case you wouldn't plane the crown off.
 
  #4  
Old 05-02-18, 05:40 PM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,335
Received 49 Votes on 46 Posts
I think composite is a lot like a vinyl floor in how well it telegraphs inconsistencies from below. I would shoot for as even as you can get.
 
  #5  
Old 05-02-18, 05:52 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 4,448
Received 106 Votes on 97 Posts
I've built 3 composit decks with various styles of decking and befroe that 3 wood decks (never again) even now with a 10 year old deck that I'm sure has changed shape due to structure boards warping and drying out nothing is any more obvious than any other material.

I would agree, anything under 1/8" is not an issue, anything greater and I'd be changing it out regardless.

BTW you will never regret the decision to go composit, just did a clean up on the current 10 year old deck and it still looks, and feels like new.

Have never had to stain, never had to replace a board, never had to sand, that's the long term savings!
 
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
Display Modes
 
Ask a Question
Question Title:
Description: