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-   -   Dilemma with lifting floor joist (http://www.diychatroom.com/f19/dilemma-lifting-floor-joist-135857/)

WillK 03-03-2012 10:11 PM

Dilemma with lifting floor joist
 
Okay. I think I have an idea what I need to do, but I need to run it by folks here to see if there are any other ideas because I'm not entirely satisfied with the solution I'm thinking of, and I can't think of any others...

Here's the situation. My house, built in 1917, has no foundation. It's mostly supported by cement blocks under floor joists, the blocks are sitting directly on dirt. It is a conditioned, enclosed and ventilated crawlspace.

I've gotten plans for adding beams to support the joists, these beams being of triple 2x10 built up construction, supported by 6x6 posts on 24x24x10 footings. Originally specified as 2 beams with reuse of the original triple 2x6 beam, but I'm building 4 beams because the original triple 2x6 beam is in bad shape, the joints are unsupported and the furnace under it makes it impractical to replace directly... I further intend to replace the 2x6 joists with larger 2x8 joists, and I do mean replace and not just sister.

At this point, I have 3 of the 4 beams built. I am digging footings for the 4th beam, but first I must clear cement blocks supporting the ends of the joists under the southern exterior wall.

In order to remove or relocate a stack of cement blockst before digging a footing, I am jacking the floor joists by hydraulic jack under a temporary triple 2x6 beam which lifts 4 floor joists at a time.

Here's where the difficulty comes in. The first footing I'm trying to clear, when I jack up my temporary beam, the floor lifts, the exterior wall does not. I ran into this issue once before.. The solution was to sister the joist because the joist was too deteriorated to lift the exterior wall.

However, in the earlier case there was a 2x6 under the end of the floor joist, something like a sill plate. In the present area I'm working - the board is smaller, it's irregular, and the joist has crushed into it. I can not get my 2x6 sister under the exterior wall.

What are my options to get a 2x6 joist into the space under the exterior wall so I can lift... If I notch the end of the sister, will it still be strong enough to lift the wall when I jack under it away from the wall?

I'm left with the option of cutting away with a sawzall this board that interferes with the 2x6 sister joist I intend to add... Obviously that's risky because it undermines the support for floor joists between stacks of cement blocks.

Or I just leave the cement blocks where they are and build the beam another 8" away from the wall... Which will in the end be supported by a foundation wall when I get that done.

Any other ideas or pros/cons on the ideas I'm pondering?

titanoman 03-03-2012 11:32 PM

All I know, is if you want to lift part of the house, and not all the house, and the house is completely sheered together, something has to give.
Like the joists/floor in this case.
You can't lift part of a house.
You're trying to lift the whole house from one spot.
(lift up one end of a box. The whole box goes up, on an angle, of course)
How high are you trying to go, you think?
Without a picture, I can't guess how many jacks you should have, or how many beams you need.
But more than 2.
House movers are good about figuring that sort of thing.

joecaption 03-03-2012 11:57 PM

Quote:

Originally Posted by WillK (Post 869700)
Okay. I think I have an idea what I need to do, but I need to run it by folks here to see if there are any other ideas because I'm not entirely satisfied with the solution I'm thinking of, and I can't think of any others...

Here's the situation. My house, built in 1917, has no foundation. It's mostly supported by cement blocks under floor joists, the blocks are sitting directly on dirt. It is a conditioned, enclosed and ventilated crawlspace.

I've gotten plans for adding beams to support the joists, these beams being of triple 2x10 built up construction, supported by 6x6 posts on 24x24x10 footings. Originally specified as 2 beams with reuse of the original triple 2x6 beam, but I'm building 4 beams because the original triple 2x6 beam is in bad shape, the joints are unsupported and the furnace under it makes it impractical to replace directly... I further intend to replace the 2x6 joists with larger 2x8 joists, and I do mean replace and not just sister.

At this point, I have 3 of the 4 beams built. I am digging footings for the 4th beam, but first I must clear cement blocks supporting the ends of the joists under the southern exterior wall.

In order to remove or relocate a stack of cement blockst before digging a footing, I am jacking the floor joists by hydraulic jack under a temporary triple 2x6 beam which lifts 4 floor joists at a time.

Here's where the difficulty comes in. The first footing I'm trying to clear, when I jack up my temporary beam, the floor lifts, the exterior wall does not. I ran into this issue once before.. The solution was to sister the joist because the joist was too deteriorated to lift the exterior wall.

However, in the earlier case there was a 2x6 under the end of the floor joist, something like a sill plate. In the present area I'm working - the board is smaller, it's irregular, and the joist has crushed into it. I can not get my 2x6 sister under the exterior wall.

What are my options to get a 2x6 joist into the space under the exterior wall so I can lift... If I notch the end of the sister, will it still be strong enough to lift the wall when I jack under it away from the wall?

I'm left with the option of cutting away with a sawzall this board that interferes with the 2x6 sister joist I intend to add... Obviously that's risky because it undermines the support for floor joists between stacks of cement blocks.

Or I just leave the cement blocks where they are and build the beam another 8" away from the wall... Which will in the end be supported by a foundation wall when I get that done.

Any other ideas or pros/cons on the ideas I'm pondering?

Where did you get these plans? No engineer would ever suggest using 6 X 6's instead of real piers.
The piers need to be a double row of concrete blocks not a 6 X 6's.
Your whole plan sounds kind of funky to me.
As already mentioned, trying to lift any house in sections always results in lots of uneven floors, wall damage and out of skew doorways.
If the plan is to add a whole new foundation then the whole house needs to be lifted at once, footing is pored, foundation built then the house is lowered.

titanoman 03-04-2012 12:04 AM

...buckled siding, busted windows, broken facia/gutters, buckled roof, broken water-pipes...

It has stood there for almost 100 years. Why change things now?

WillK 03-04-2012 06:24 AM

As I said, I'm only trying to lift far enough to remove the cement blocks and/or move them to a location that doesn't interfere with the footing I need to dig.

For the number of times I've posted about this project and the number of problems I've described I'd thiinnk it'd be clear that the only way that this house has stood for 93 years has been by having a huge number of half-baked repairs done to the rotting undersized lumber that holds it up. It should really say something that I bought the house for $25,000 in a city where most of the houses list and sell around $150k and up... This house can't be mortgaged and /the floors are all over the place for not levelness... I could go on, but pictures would probably do more to describe it so I'll leave it at that until I come back with pictures.

AndyGump 03-04-2012 11:29 AM

It sounds like you need to tie the floor joists in to the studs. You could place a 2x10 on edge on the floor next to wall and lag screw into that then try your lift.
I have done this before with success.

Andy.

titanoman 03-04-2012 12:26 PM

Quote:

Originally Posted by AndyGump
It sounds like you need to tie the floor joists in to the studs. You could place a 2x10 on edge on the floor next to wall and lag screw into that then try your lift.
I have done this before with success.

Andy.

I'm sure Andy will accept all liability when your house is so buckled and broken up that a new foundation will be the least of your problems.

WillK 03-05-2012 08:33 AM

Quote:

Originally Posted by titanoman (Post 870098)
I'm sure Andy will accept all liability when your house is so buckled and broken up that a new foundation will be the least of your problems.

You say that as if I'm not already at that point.

I'm looking at the overall project as if I'm going to be replacing everything as though the house was being built new, but keeping a roof over it while in progress.

Pictures are coming soon.

WillK 03-05-2012 08:35 AM

Quote:

Originally Posted by AndyGump (Post 870054)
It sounds like you need to tie the floor joists in to the studs. You could place a 2x10 on edge on the floor next to wall and lag screw into that then try your lift.
I have done this before with success.

Andy.

At this point I've been able to get the wall to lift with the floor by sistering 4' long lengths of new 2x6 onto the 3 of the joists before I start a lift. The issue is apparently more complicated than that, but I'll have to explain with pictures when I get a chance later this morning, but at this time I have to head to another meeting here at work.

WillK 03-05-2012 09:47 AM

1 Attachment(s)
Okay. So at this point, I've sistered 3 joists and the subsequent lift attempt was successful at lifting the wall with the floor, but not removing load from the cement blocks sufficiently to relocate the stack.

Referencing the picture below, the picture was taken before I sisted onto the joists, I have cut away the top board behind "Joist A" so I can add the sister joist at that point.

This top board is actually a 2x4 with the top rounded off because it was cut from the edge of the lumber, so one side actually does not have any flat at all. Behind this board was a pile of wood dust from whatever was originally a sill-plate type structural member having completely rotted away. Subfloor near the wall has been replaced with particle board.

The middle board spans multiple floor joists, and the board on the bottom which rests directly on the cement blocks only sits on these blocks. I can lift the floor joists and walls enough to unload the top board so it could be removed, but I haven't removed it because until I'm able to move the cement blocks, my intent is to chagne nothing.

I think at this point I'm going to change my approach to leave this stack of cement blocks where it is, and the footer location will move forward reducing the span between beam supports at this point. It may mean I have to increase the number of footers I'll have to dig over the length of the beam, so I'll just have to deal with that.


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