Jacking Up Cottage Problem

[imported_gbeichho]

This is a semi-continued thread from a former topic:

http://www.selfhelpforums.com/viewtopic.php?t=2024

Quick Recap:

As per the suggestions from this forum I was going to install jack joists (extended outside the cottage) every 4 joists so I could raise the one side and install a foundation wall along the one side. (currently supported by a couple of piers).

So after I installed one jack joist successfully, I ran into several complications for which I am at a loss on how to proceed.

Firstly, I looks like the main beam along this side is rotting. This might be the reason this side was sinking (the piers might actually be stable).

http://www.eichholzer.net/webpostings/RottingBeam286.JPG

http://www.eichholzer.net/webpostings/RottingBeam186.JPG

I'm pretty sure it's rotting because of the moisture. This beam is a couple of inches above grade in a few places and it is only protected by the metal sheathing and obviously the moisture has gotten into the wood.

So my simple project of jack the side, dig, and build a blocked foundation wall has now turned into jack up the side, replace the beam and then build the wall.

I assume the now the only way to prop/jack up the cottage is to put supports on the floor joists just behind the beam. This will allow me to replace the beam (made of 3 2x6).

http://www.eichholzer.net/webpostings/JackProblem.bmp

Here are the problems:
1) Since the beam is basically at grade, the clearance behind is only about 6" (mostly enough room for me to crawl underneath on my belly or back, but I can't roll and in some places there is a rock where I can't get to from underneath).

If I plan to support the floor joists with a 6" beam (I have ~30' of 6x6s), I'll have no room to get a jack underneath this beam.

2) I can't even install temporary jack joists because at one end of the wall, it is rock (big ones) so I can't even dig a full 6" from the outside (or underneath for that matter) at that section to get a jack under the main beam.

3) Given the rock directly below a good portion of the main beam, I won't even be able to build the blocked wall.

The only solution I could think of is to get a jack hammer, and break up the rock to be able to jack up the beam and put supports on the floor joists behind. Then I could put the proper blocked wall there.

Any suggestions are welcome -- George

[Wgoodrich]

Get a few steel I beams or solid square bars large enough to carry the load of that side of the house same frequency as before. Slide the Steel under the beam into the crawl onto a rock [seems you have plenty of them to hit on]. Then using as a lever jack the end of the steel beams sticking under the house on the rocks for solid pivot and sticking out beyond the house far enough to get a jack under them. Then jack up as you need to take pressure off the beam. Then buy a 6 x 6 and a 4x4 post. Cut the 6x6 short enough to lay under the house on the ground supporting the 4x4 laying across several floor joists. Cut the 6x6 as posts so that when the 4x4 sits down on the 6x6 posts legs the beam you need to replace is free of your piers. Then cut out the rotted section of beam and dig your footer and lay your foundation up to place where it is supposed to be. Then replace with a new TREATED BEAM same size as old beam cut to length fitting end to end to the remainging good part of the beam. Then using lag bolts or long bolts and nuts bolt a steel plat across the joint of old beam and new beam to secure as one long beam repaired. Then again jack up the house using the steel levers and use a hook to pull out the temp 4x4 and 6x6 jack post supports. Then let the house back down on the new footing, foundation and partially replaced beam. Re-install your siding from the bottom up as discribed in previous replies.

Note;

EAsy jacking is if you are on a corner you can use a 2x12 to nail flat on surface of siding through the siding into each stud for length needing to jack up plus 2 feet past joint of old good section of beam allowing your 2x12 to stick out the end of the wall past the corner of the house. This will also jack up the house as you need.

Just do not trust the lever jacks or the 2x12 jack board to crawl under that house. If it fails you may be making a lethal mistake. Ensure solid setting and be safe use a long pole to push 4x4 in place with 6x6 shoved into place using another pole. Stay out of that crawl while house is jacked up. You can shove using poles those posts and jack posts in place without entering that crawl.

Remembe jack only what you have to in order to get the job done to limit wall surface damage inside the house.

Be safe.

Wg

[imported_gbeichho]

Yes, that gives me several very good ideas. I think through a combination of those suggestions I should be able to jack up the cottage and support it.

As a note, I suspect I will probably replace the whole length of the beam because it was very soft in several sections when I tested it, and I'm pretty sure the old beam is not treated. Since it's only 27 feet, I think it's safest to replace the whole thing while I've got it all available.

My last question is about the footing and foundation/blocked wall. I was originally planning to build a blocked wall 1-2 blocks high (or low), but given that only 60% of the section is dirt that I can dig down for the footing. The rest is basically rocky (maybe 2-4 inches of dirt followed by both solid and broken rock. In one section a big rock actually rises a bit above grade.

How do I build a continuous foundation/blocked wall on this?

Thanks, George

[Wgoodrich]

The Code allows a footing to set on rock if solid rock without passing below frost depth. With this in mind I would not try to pour partial footing then use block. I would dig to below frost depth that area you can dig out. Then that part that is rock leave existing as is. Then form up a curtain wall same as would be a block wall in size being 8" in width. Then pour concrete into the trench and forms to that it is about 8" above the rock making a flat poured concrete footing/foundation curtain wall using the bottom of the trench where dug then what is called a step footing to the top of the rock as square as possible pouring over the rock as the bottom of the footer were the rock or rocks are. Then lay concrete block to the height you need on the top of that poured concrete footer/foundation wall. If you need to you can form and pour a footer / foundation curtain wall from the bottom of the trench stepped up on top of the rock as the bottom over the rock to the level of the top of the foundation all in one pour if you so desire considering the conditions this may be you best choice.

You can do it either way above discribed.

Don't forget on the top of the foundation to install anchor bolts long enough to pass through the beam to bolt the house to the foundation embedded in the concrete or block layed.

Does that answer some doubts for you?

Wg

[imported_gbeichho]

Pretty much, thanks. The only reason we're not planning to dig down below the frost line is because we're trying to match the foundation on the other side which is a small footing 3-9 inches below grade with a blocked wall.

I think I understand the part about the stepped concrete though. That would apply for any type of footing.

I also suspect that the rock is only 3-4 feet down on the side where I am able to dig, since the whole area is very rocky.

I will have a fun time trying to dig out all the dirt to get to rock...

Thanks,

George