Jacking Floor Joists In Multi-level

neolitic

Damn close, but I came to
in time.

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greg24k

Flush header is the way to go, if you can use proper beam size to be flush and at the same time support the D&L loads. Using flush headers in existing structures you might end up re-routing some wiring, etc.

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Home Work Pro

I have to admit that I have had to remove a jack stud or 2 before.

It's easy to get going too fast when the picture is clear.

I have a nice picture of 1 I did last year but I don't know how to move a picture from a file to here.

Brian

Home Work Pro

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greg24k

I did this job a while back. Flush beam could not be used in this situation because of the span and the load the beam was carrying, so it was lower then the ceiling beams. But all the joist where cut, the beam was placed in between and all the joists where leveled and attached with hangers.

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slowforthecones

I've got a question, I'm planning to take on a edwardian style restoration job of a 4 story building located on a slope. There is no garage currently and owner wants to add a garage on ground level. The building would need to be jacked up by about 2-6 inches to fix a settlement problem.

Any ideas or techniques?

neolitic

Far too vague.

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genecarp

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72chevy4x4

how about digging out the footer and dropping it 2-6 inches to get it all in level

A four story building-wow!

slowforthecones

I'll come up with some drawings in the next few weeks. Just a old house in California I was asked to give a price on. The clients engineer has an estimated jack up of 2-6 inches. They asked for some possible approachs and methods I would use during construction including some underpinning of the buildings on both sides.

genecarp

OK, hear you go SOP FOR JACKING
1- I USE a series of bottle jacks, i have had welded a piece of steel that sits on top of the piston, then transistions to a SQ 4X4 CUP TO ACCEPT A 4X4
2- THE area that you are lifting needs to be fully inspected, remove anything that can be removed, and the HO must understand the risks to the structure. Primary concerns are cracked plaster, Tile--mostly superficial types of damage.
3-The process is slow, the house fairs much better when the lift is preformed over a number of days, allowing the home to adjust, remember it did not settle overnight(dont rush).
4-Now comes the fun part, expose all areas that are relevant, jacking points must be specific, and a full knowledge of framing and construction is neccesary at this point, every job is different but the principals are always the same
5-In some cases cutting out nails will help the lift, i have always marveled at the holding power of one nail that is located in some unusual angle, and how it can impact the job, so look around, cut and relieve pressure points that make sense.
6-Ready to go, start jacking, the more jacks the better, apply equal pressure moving down the line, as the pressure is relieved, add to each one nice an easy. Often i will put some kickout safety bracing in place, When a jack kicks out it can be pretty intense, some 2x4s across the area can prevent injury
7-You should start to hear the scary creaking at this point, now the jacks are loaded and the beam is starting to lift. when it gets real hairy we would usually elect the new guy to deliver the next series of cranks.
8-Know when to call it a day, come back tommorow, hit it again.
9-Now, when you think the lift is complete, go a little further, when you lock it in and tranfer the load to your new support, you will loose some of your gains.

Thats it in a nutshell, this process should only be attempted by a very experianced person- structural work also can be very profitable. G

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72chevy4x4

just to follow up on Gene's comment #6: an understanding of the physics of what's going on is helpful. A jack that kicks out under pressure can cause a lot of damage if it hits your knee/leg or other body part.

In the past, I've used a string to aid in knowing when I've got the beam in a straight line.

slowforthecones

good ideas, thanks! I've done plenty of single family 2 & 3 levels but nothing the scope of this on a slope. I've done some exploratory testing, the ground floor I cut out the subfloor exposing the joists so i'm able to see the framing plan. there are no official plans on this home except a basic survey because this was a pre-1910 home, city hall burned to the ground in 1906.