I need to jack up a post

Reply

  #1  
Old 09-03-14, 05:56 PM
Z
Member
Thread Starter
Join Date: Sep 2014
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
I need to jack up a post

I've got a three story porch. The side attached to the house is fine, but the other side was made on some pretty lousy foundation, it rotted out and sank about eight inches.

I've dug my five foot holes, filled said holes with concrete to use to support a bottom plate so when I rebuild this thing it will be more solidly placed. Now all I have to do is jack it up. But I'm iffy on exactly how to jack up a post.

The problem is that every peice of advice i've ever seen on how to jack up a house or deck - advises you not on how to jack up a post, but rather, on how to jack up the beam the post connects to. I do not have access to that beam, because stairs are in the way. I need to jack up the post itself. Preferably, without jacking it up from the bottom - for two reasons. Firstly, the bottom is on the ground for most of the posts I need to jack up (one is accessible), and secondly, if I jack up the post itself from the bottom, I will not be able to put the bottom plate properly under the post once the post is the correct height.

How does one jack up a 4X4? Is there some special tool I'm missing?
 
Sponsored Links
  #2  
Old 09-03-14, 06:13 PM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,512
Received 37 Votes on 34 Posts
Others will be along who know more about this than I do, but how much weight is up there?
Can you attach anything to this 4x4 or drill a hole through it?
A picture of what you are looking at would help as well.

Bud
 
  #3  
Old 09-03-14, 06:15 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 5 Votes on 5 Posts
Welcome to the forums! It may help if you post pictures of your situation so we can see what you see. Normal lifting will be done by the beam, not the post.
 
  #4  
Old 09-03-14, 09:57 PM
Z
Member
Thread Starter
Join Date: Sep 2014
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
In this case, it is an enclosed staircase porch. So on the side with the stairs, that post has a staircase blocking below access to the top plate - and due to it being enclosed, I can't access the top plate from the outside of the porch either. (although I'd have to do that at a heck of an angle even if I did tear down the wall to access that)

I'll see if I can get a video on youtube....
 
  #5  
Old 09-04-14, 05:08 AM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 25,822
Received 641 Votes on 593 Posts
Why can't you put a bottle jack under a 2nd post, setting it off to the side of where the primary post needs to be? Once you jack it up to the height it needs to be, then put the primary post in and release the bottle jack.

If you can't do that because there is wall in the way of a 2nd post location, I'd say that you have to lag something horizontally across either the interior or exterior side of the wall studs to jack against. Perhaps a couple 2x6's placed one above the other... several feet apart... that you could then notch a temporary 4x4 over, lagging the 4x4 to them as well. Then jack under that 4x4.

I think the alternative to that is jacking up a second, shorter post with a bottle jack, then temporarily bracing the structure with strongbacks at an angle to a mudsill on the ground... releasing the bottle jack... letting the mudsill settle into the ground... then probably jacking it up again... moving the strong backs so they are tighter and release the bottle jack again so that you can get it out of the way and hope you've got it held where it needs to be, or just a bit higher so that you can put the primary post in.
 
  #6  
Old 09-04-14, 09:22 AM
Z
Member
Thread Starter
Join Date: Sep 2014
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
posts and beams - YouTube

Made a quick youtube video of the beam. Up until the second landing, all the boards are simply nailed into the side of the beam and could not be used for jacking.

posts and beams - YouTube

I suppose it is possible to sister in a post, but I'm not sure how I'd secure it in with enough force to not have it come off when jacking up the porch.
 
  #7  
Old 09-04-14, 03:58 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 25,822
Received 641 Votes on 593 Posts
So you're not replacing the 4x4 post?

This doesn't look that difficult. Set the bottle jack next to the 4x4 post. Set a long piece of 4x4 on top of the bottle jack. Sister those two 4x4's together by lagging them both together using 4 or 5 lags... 1/2" x 6" or more. (drill 3/8" pilot holes for them.) Jack it up. Add a block under the original post. Let the bottle jack down. Repeat as needed, blocking up the jack as you go to raise it, if needed.) Once you have it to your final height, add a permanent 4x4 filler block underneath your post and let the jack down. Remove the 4x4 you sistered on. Sister a 2x4 onto each side of the 4x4 that's as long as you can make it to tie it all together.
 
  #8  
Old 09-05-14, 05:56 AM
Z
Member
Thread Starter
Join Date: Sep 2014
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
Not planning on replacing the post, just jacking it up. I'll probably remove an inch from the bottom, there's a small amount of rot in the corner. I'd have preferred if they used an actual 4x4 instead of nail 2 2x4's together, but clearly I didn't have a say in the design of this place.

Thanks for the advice... I'll have to sister a post in with lags.
 
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: