Does typical treated pine decking shrink?

Reply

  #1  
Old 12-09-19, 12:59 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 43
Received 0 Votes on 0 Posts
Does typical treated pine decking shrink?

I have one of those situations where one of the inner boards (naturally) on my back deck has a couple of places of rot in an overall length of about 8'. I thought I could simply go to Lowes or HD and grab a length and replace the bad timber. (I do not know the source of the original lumber but it, and the railings, look like store-bought stock.)

However, when I got home the new wood filled 100% of the space between the sister planks? The established planks have about a 5/8's gap. Is widthwise shrinkage the norm?

I figure I could rip a new piece into the correct width and shape a round edge to fake it in, but... I am back to shrinkage?! It is right where your eye see it climbing the steps. Thanks.

Jim
 
Sponsored Links
  #2  
Old 12-09-19, 02:09 PM
Member
Join Date: Sep 2019
Location: Canada
Posts: 638
Received 56 Votes on 52 Posts
Yes it shrinks.

Even cedar will shrink but it takes longer.
 
  #3  
Old 12-09-19, 02:17 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,413
Received 153 Votes on 136 Posts
As long as it fits in the gap I'd nail/screw it in place. As noted above it will shrink as it dries out.
I don't know what the deal is but on my son's deck I went to replace a couple of rotten boards and they were less than 5.5" wide and I had to rip one of them to make them fit.
 
  #4  
Old 12-09-19, 05:23 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,377
Received 296 Votes on 270 Posts
I often install 5/4 treated pine decking touching, with no gaps between the boards knowing that the wood will shrink and open up a reasonable gap.
 
Norm201 voted this post useful.
  #5  
Old 12-09-19, 05:28 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 4,784
Received 141 Votes on 131 Posts
planks have about a 5/8's gap.
Is that a typo, 1/8" is/should be the norm!
 
  #6  
Old 12-09-19, 05:37 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 7,744
Received 106 Votes on 97 Posts
The technical answer is treated wood should not shrink if if was previously kiln dried or aged for the proper amount of time.

The problem is that in today's market, proper kiln drying us expensive and is therefor shorted by time an very often green wood is treated then left to dry at the consumer market level.

When installing a new wood fence that encloses your yard you may hear an echo for the first year until the boards shrinks and the sound escapes through the gaps.
 
  #7  
Old 12-10-19, 04:19 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,413
Received 153 Votes on 136 Posts
Almost all the PT wood sold at a big box or lumber yard has not been dried from the PT process. Some places will have kiln dried PT but it's at a premium price.

My front and back porch have sawmil lumber for decking, they were installed tight but shrunk enough to have about a 5/8" gap between boards. My side deck was also installed tight and shrunk to about a 1/4" gap.
 
  #8  
Old 12-10-19, 06:44 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 4,784
Received 141 Votes on 131 Posts
Just watch when your walking around in your stiletto high heels!!
 
  #9  
Old 12-10-19, 11:56 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,413
Received 153 Votes on 136 Posts
Ya, my wife used to have one pair that would occasionally get stuck in between the boards on the front porch.
 
  #10  
Old 01-13-20, 02:14 PM
Member
Join Date: Jul 2014
Location: usa
Posts: 226
Received 0 Votes on 0 Posts
My side deck was also installed tight and shrunk to about a 1/4" gap.

I would still space wood decking a tad. I'd just take it out and plane it down a bit or sander it or whatever you got.

it does shrink but you never really know how much. It's better to have a slightly larger space than no space. no space will pool up and rot wood. big box store decking wood is kept indoors in the heat if winter, and might be somewhat dry. fresh PT decking from lumber yard will usually be wetter piratically dripping when you screw/nail it, and will shrink more so.

also know that wood decking is cupped longways, install it so it's not collecting water.

here: saying the same thing, and I agree, and I think that wood is already dry/shrunk hence the long split from the screw which isn't even close to the edge
https://youtu.be/sg0Gyp6Zelk?t=125

I mean, in your case, just one board not a big problem but I would slightly space wood decking if doing the whole thing.
 
  #11  
Old 01-13-20, 04:20 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 7,744
Received 106 Votes on 97 Posts
Well, you can't argue with proof via video. Gunner is correct, you leave some kind of space. But as most of the above responses have shown, most likely it will shrink.
So to answer the original OP's question, and since it's in the middle, I would not cut or shave it, betting on the fact that the odds are it will shrink.
 
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: