Warping oak stair treads - Woodworking Talk - Woodworkers Forum
 
Thread Tools Display Modes
post #1 of 8 Old 02-25-2013, 12:27 PM Thread Starter
Junior Member
 
Join Date: Feb 2013
Posts: 3
View J WILSON's Photo Album My Photos
Warping oak stair treads

As a contractor, I recently built a stairwell transition between a garage and the basement/main floor of the house. A stair company built the stairs. The top three treads of stairs leading to the basement began cupping, so I replaced them myself with the homeowner staining and sealing before installation. Now the top two treads are warping again. No sign of moisture. Both entrances to upper and lower levels to the house are cased openings. What could cause this?
J WILSON is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 02-25-2013, 01:45 PM
Senior Member
 
Join Date: Apr 2011
Posts: 305
View DannyT's Photo Album My Photos
were the bottom and the ends sealed also?
DannyT is offline  
post #3 of 8 Old 02-25-2013, 08:44 PM
recently retired
 
Join Date: Sep 2010
Location: Seattle
Posts: 174
View Keith Mathewson's Photo Album My Photos
Is there a difference in which spaces are heated?

I'm guessing that these are not housed stairs.
Keith Mathewson is offline  
Sponsored Links
Advertisement
 
post #4 of 8 Old 02-25-2013, 10:41 PM
Senior Member
 
Join Date: Jan 2011
Location: New Hill, North Carolina
Posts: 154
View scsmith42's Photo Album My Photos
Cupping in dry wood is typically caused by differences in RH% on each side of the wood. You can minimize it by finishing both sides of the board. Additionally, it sounds like the basement may be more humid than the rest of the house.
scsmith42 is offline  
post #5 of 8 Old 02-26-2013, 11:16 AM
Senior Member
 
Brian T.'s Avatar
 
Join Date: Dec 2012
Location: McBride, BC
Posts: 2,648
View Brian T.'s Photo Album My Photos
Air dried outdoors under cover, the equilibrium moisture content should be in the 12-15% range.
Indoors in service, that MC can drop as low as 4-5% and movement is probable. Particularly if the wood was cut tangentially, parallel to the plane of the growth rings.
The only fix that I've ever see was a set of ripping cuts, hidden on the underside of the wood, maybe 1/2 the thickness of the wood. That appeared to do a good job of alleviating the cupping movement.
A glue-up of narrow pieces works for this as well.
Brian T. is offline  
post #6 of 8 Old 02-26-2013, 02:09 PM Thread Starter
Junior Member
 
Join Date: Feb 2013
Posts: 3
View J WILSON's Photo Album My Photos
Quote:
Originally Posted by DannyT View Post
were the bottom and the ends sealed also?
Yes, the homeowner sealed both the top and bottom.
J WILSON is offline  
post #7 of 8 Old 02-26-2013, 02:12 PM Thread Starter
Junior Member
 
Join Date: Feb 2013
Posts: 3
View J WILSON's Photo Album My Photos
Quote:
Originally Posted by Keith Mathewson View Post
Is there a difference in which spaces are heated?

I'm guessing that these are not housed stairs.
The transition stairwell is heated. Obviously, the adjacent garage is not. Both levels of the house have open entryways.
J WILSON is offline  
post #8 of 8 Old 02-26-2013, 04:38 PM
Senior Member
 
Join Date: Jan 2011
Location: New Hill, North Carolina
Posts: 154
View scsmith42's Photo Album My Photos
If they are cupping "towards the bark", then it sounds like the lumber was not properly dried. It is the natural tendency for the growth rings on lumber to "try to straighten out" during the drying process.

On the other hand, if they are all cupping the same direction, irrespective of the orientation of the growth rings, then it sounds like there is a problem in RH% on one side of the board.

Lumber will cup towards the dry side.
scsmith42 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Refinishing Stair Treads - HELP Woodworking Amateur Wood Finishing 5 11-24-2012 09:11 AM
Stair Treads ellemarshall General Woodworking Discussion 6 10-30-2012 12:06 AM
Help with Stair Treads natetron66 Design & Plans 5 09-28-2012 01:04 PM
Hardwood stair treads BZawat General Woodworking Discussion 8 09-22-2012 09:31 AM
oak stair treads bigredc General Woodworking Discussion 5 08-30-2008 06:08 AM

Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome