Will this plan to lift joists work?

Ask your questions regarding the exterior of your house - siding, roofing, etc.
Post Reply
KeepTryin
Posts: 16
Joined: Wed Oct 09, 2013 11:17 am
Location: Western New York

Will this plan to lift joists work?

Post by KeepTryin » Mon Nov 13, 2017 10:12 pm

Hello,

I'm afraid that I'm going to need to replace a section of my home's sill plate and rim joist.
I discovered a significant amount of rot that goes right through the sill plate and the bottom inch or so of the rim joist.

In order to replace the sill and rim joist, I assume that I will need to take some of the weight off of them.
That leads me to my question. There is 2x4 framing in the basement along the wall where I will need to replace a section of the mud sill and rim joist. Would it be sufficient for me to force shims or some form of wedge between the top of the 2x4 framing and the joist to take the weight off of the existing rim joist?
Joists-From-Basement.jpg
Joists-From-Basement.jpg (39.5 KiB) Viewed 54 times
Please note, the blankets stuffed in between the joists are a temporary measure. I removed the
insulation so that I could have a look at the condition of the joists from the inside.

One problem I'm predicting is that the top plate of the 2x4 wall is likely nailed into the joist.

Will my plan to use shims between the 2x4 top plate and the joist work?
Are there potential problems that I should be aware of?

Thank you in advance.


User avatar
A. Spruce
Posts: 2488
Joined: Tue Aug 16, 2016 5:23 pm
Location: California, USA

Re: Will this plan to lift joists work?

Post by A. Spruce » Mon Nov 13, 2017 11:44 pm

You're better off jacking the joists in question, you're going to get better and more controlled lift this way. A 4x6 header across the joists in question should suffice, lift and support little bits at a time until you've got enough space to do the repair, then lower everything back into place for final fastening.

For fasteners between the wall and joists, lift the joists slightly first, then prybar and/or wedge the top plate to get some air gap, then sawzall the fasteners. If you've only got a couple of joists to deal with, you won't need to worry about refastening the wall, most likely, though you could install a couple toe-nails to reconnect the two.
I'm CDO, it's the same thing as OCD, but in alphabetical order like it should be! I've also got a touch of AD/OS, Attention Deficit . . . Oh, Shiny!

KeepTryin
Posts: 16
Joined: Wed Oct 09, 2013 11:17 am
Location: Western New York

Re: Will this plan to lift joists work?

Post by KeepTryin » Tue Nov 14, 2017 2:16 pm

Thank you @A.Spruce
Do you think this could be done with one car jack and maybe three to four 4x4 temporary columns? I'd imagine jacking a little near one column, then shimming the space created between the column and the temporary header, then moving on to the next column, etc...
Or, am I going to need three or four jacks--in which case I hope I can rent them?

Thanks again.

User avatar
A. Spruce
Posts: 2488
Joined: Tue Aug 16, 2016 5:23 pm
Location: California, USA

Re: Will this plan to lift joists work?

Post by A. Spruce » Tue Nov 14, 2017 3:25 pm

The better way to go would be a hydraulic bottle jack of 4 tons or more. You're not actually going to be lifting that much weight, but you absolutely want more jack than you're ever going to need for safety reasons. I'd be concerned that a car jack wouldn't have the capacity that you want for your safety margin.

Assuming you're going to lift no more than 3 or 4 joists at a time, the 4x6 header and 4x4 temporary posts will suffice. I think I'd create a pocket at the header/post connection that keeps the posts situated under the header, yet allows them to move up/down independently so that as you jack you can shim between the header/post. To do this, I'd nail a 2x4 on either side of the header, then 3 or 4" below the header attach 2x4 cross bars to the vertical 2x, this will allow you a pocket to insert shims between the header and post. Shim both sides of each post so that the header/posts bear the weight evenly.
I'm CDO, it's the same thing as OCD, but in alphabetical order like it should be! I've also got a touch of AD/OS, Attention Deficit . . . Oh, Shiny!

KeepTryin
Posts: 16
Joined: Wed Oct 09, 2013 11:17 am
Location: Western New York

Re: Will this plan to lift joists work?

Post by KeepTryin » Tue Nov 14, 2017 9:50 pm

That makes sense @A.Spruce
Thank you.

User avatar
A. Spruce
Posts: 2488
Joined: Tue Aug 16, 2016 5:23 pm
Location: California, USA

Re: Will this plan to lift joists work?

Post by A. Spruce » Tue Nov 14, 2017 11:00 pm

Lastly, don't leave the weight on the jack while you're working. It's ok for the jack to help with the weight, but not hold it by itself because if there is a failure it all comes down on you. Jack it, shore it, relieve weight on the shoring, go to work.
I'm CDO, it's the same thing as OCD, but in alphabetical order like it should be! I've also got a touch of AD/OS, Attention Deficit . . . Oh, Shiny!

Post Reply