How Can I Flatten This Floor? - Flooring - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Flooring

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 10-18-2009, 10:29 AM   #1
Member
 
Join Date: Dec 2007
Posts: 39
Rewards Points: 25
Default

How can I flatten this floor?





As you can see I have access to the floor from below. Is it possible to jack up the sub-floor and then sister the joist to hold it in place without jacking up the joist? When I put the level on the joists they seem flat enough but the floor above is sagging. The house is 100 years old and I'd prefer not to touch the joist. Any suggestions for good fix that lets me keep the original floor?

Thanks again for the continued help.

James

Advertisement

JamesEric is offline   Reply With Quote
Old 10-18-2009, 10:38 AM   #2
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

How can I flatten this floor?


You want to jack up the floor without jacking up the joist?

The sub-floor is not designed to hold the weight from jacking
If you want to destroy the floor trying to jack up the sub-floor would be a good way to do it

You need to jack up the joists little by little over time to bring this back into place
Do you see any crack or failure in the joist?

Advertisement

Scuba_Dave is offline   Reply With Quote
Old 10-18-2009, 10:43 AM   #3
Member
 
Join Date: Dec 2007
Posts: 39
Rewards Points: 25
Default

How can I flatten this floor?


No cracks or failures in the joist. Why couldn't the subfloor sit on the sister joist instead on the original joist?
JamesEric is offline   Reply With Quote
Old 10-18-2009, 11:25 AM   #4
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 4,300
Rewards Points: 2,178
Default

How can I flatten this floor?


If the existing joists are level, there is no reason to jack up the joists at all. You need to determine why, if the joists are level as you indicate, the floor is sagging. Usually a sagging floor indicates sagging joists, but from the first picture it looks to me like the floor sags much more than the joist ever would. Also, the basement photo seems to show the joists in very good condition.

I suspect that the floor is not firmly attached to the joists. This could indicate a problem with the subfloor installation, I could not tell much from the photos. If the subfloor is not properly attached to the joists, you could remove the flooring, and reattach the subfloor using screws or nails as appropriate. You may need to replace part of the subfloor, using identical thickness plywood to whatever was originally used.

If the subfloor is flat, and the floor is not, you have a different problem, which we could discuss once you determine where the problem lies.
Daniel Holzman is offline   Reply With Quote
Old 10-18-2009, 11:34 AM   #5
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

How can I flatten this floor?


One problem will be that the flooring is now warped
Trying to jack up just the one area will push up the floor
That looks like a pretty good dip
It's also possible that the joist is level, but it was installed lower then the joists on either side
Scuba_Dave is offline   Reply With Quote
Old 10-18-2009, 12:07 PM   #6
Member
 
Join Date: Dec 2007
Posts: 39
Rewards Points: 25
Default

How can I flatten this floor?


I gave it a second look and that joist is bowed in the center. the joist are 1-3/4" x 11-3/4" and the span is 13 feet. I think the joist are oak. The joist are set in 4" of masonry block and brick. If I try to jack up the joist it will damage the walls above. I'd still prefer to jack up the floor and attach a sister to the original joist. Will that work?
JamesEric is offline   Reply With Quote
Old 10-18-2009, 12:54 PM   #7
Licensed Builder
 
Handyservices's Avatar
 
Join Date: Oct 2009
Location: Michigan
Posts: 24
Rewards Points: 10
Default

How can I flatten this floor?


I would locate the joist and cut the subflooring out above it for access. Then cut out the bowed joist and replace it with a new one. Replace the removed subflooring section and finally the hardwood section.

The joist could also be bowed because of improper installation of the cross braces in that area. Really hard to tell without cutting a section out.
Handyservices is offline   Reply With Quote
Old 03-20-2011, 05:32 PM   #8
Member
 
Join Date: Mar 2011
Posts: 115
Rewards Points: 75
Default

How can I flatten this floor?


I would use a really large hammer to flatten this floor

Advertisement

IceT is offline   Reply With Quote
Reply


Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
2nd floor air flow/pressure fgillis HVAC 7 02-24-2009 05:58 AM
Installing floating floor over squeaky wood floor- rip it up? (Q3) cee2ski Flooring 1 02-09-2009 07:23 AM
Changing poly type during hardwood floor refinishing redpen Flooring 17 02-03-2009 07:11 PM
Attaching 3/4 Sturdy Floor with PL 400 jamiedolan Flooring 1 09-04-2008 10:15 PM
Molde: Underside of Attic Floor stangboy68 Building & Construction 9 12-06-2007 10:53 AM




Top of Page | View New Posts