Scary little project

[David Meiland]

I'm putting together a proposal to put a foundation under the building shown in the photos. It's an ancient log cabin of historical significance; what was once an early homestead is now a public park. The county wants a concrete foundation and new joists put under it--it's currently sitting in the dirt on old 2x4 joists. The walls are ~2-1/2" thick and dovetailed at the corners. It's about 13 feet square

To do what they want means lifting the structure from the walls up, leaving the floor in place. The only way I can imagine doing this safely is to attach reinforcement to the walls, vertically, near the corners... maybe 4x4 doug fir bolted thru the existing logs. I'm thinking (3) vertical reinforcements per wall, 2 at the corners and 1 in the middle. Once those are in place additional lumber, maybe 4x12, could be bolted horizontally across the outside of the 4x4s and cantilevered a bit to provide jacking points.

Lifting a building is easy when you can just shove beams under the joists. It's a lot harder when you need to use the walls to lift, and even worse when the walls are totally suspect as they are here.

Once the building is a foot or so off the ground I can put a couple of beams under it and roll it out of the way. The floor can then be disassembled, the concrete poured, and the floor reassembled.

Any ideas? Am I insane?

[Andrew R.]

How old is it?

[David Meiland]

Apparently built in 1897.

[J.Buesking]

What's your insurance company think?

[GaryJR]

David,

This is more complicated then it looks. The entire structure can collapse if disturbed.

I seriously would consider a company that specializes in this type of work. It is very possible that once a specialist evaluates the structure he/she may recommend complete disassembly.

This is specialized restoration work.

[David Meiland]

Gary, I agree it is complicated. I think it can be stabilized enough to move it but it will get a bunch of holes drilled thru it in the process, and it will take a couple of skilled guys a week to get it set up. My proposal will require that their engineer sign off on the whole thing before it happens. For better or worse I am interested in projects like this and I can only think of 1 or 2 others locally who might tackle it.

[davenorthup]

David - my initial thought was you may be able to just "crate" the thing since it is so small. What I mean is basically frame around the outside like a shipping crate, and do the same on the inside. Run some through bolts where you can to connect the inside and outside "crating" and hopefully it will stay together... Essentially having it crated and as much as the original structure becomes immobile as possible.

Then lift, move and go from there.

Just a quick thought. Good luck if you do it!!! Sounds like a fun puzzle.

[rogerg]

Is there something you can fill the inside with to stop in from collapsing while you jack it up. Thinking outside of the box.Something that solidifies or fuses together and be able to dissolve later.The same sort of thinking puts ping pong balls into submerged boats or black ping pong balls completely covering a swimming pool helps to heat a pool, slow down evaporation and have the ability to swim through them. Not all great ideas but you get what I mean:)

roger

[Lavrans]

I just gotta throw this out: I would worry about drilling through, if only because you are disturbing (permanently) the original fabric of the structure.

13x13 isn't very heavy. The problem you're going to have is the doors- that's going to make any of the bolt-through actions only partially active.

So- what about getting your welder out there with some big L-steel roughly the depth of the walls. For the long walls you'd just use the one piece and pry the wall up just enough to push the piece under- I'd possibly go with wedges to lift and some shims to hold it up, when you hammer the L-metal in it will displace the shims. Ditto with the doors- You could/should build a brace box inside the building at the base to minimize stresses on the building. It would be best if the steel was designed to bolt together into a rigid piece (perhaps have some bolts welded on so once the sides are in some corner brackets can be welded on to make the whole thing a solid frame.

If you're already putting some bolts on that part, add a couple to allow you to build a quick "skin" of plywood around the outside of the building. With some corner boards, then some sheets of plywood or even just build some bracing truss style to keep the building from racking while moving.

Once that's done, you can either jack from some steel off the corner/bottom braces, or just use levers to lift the building (a bit at a time) until you can get some rails underneath, and then you can pull/move it.

I think it would be faster to do than to describe.

[David Meiland]

My thinking is along the lines of Dave N's... building an exterior "crate" around the building. I could get a welder out there but steel is very expensive and non-reusable in this application. A bunch of 4x4 can get reused later framing a house. Steel I would have to buy and then just give back to the welder, if he'd even take it.

Drilling this is mandatory, I see no other way. It would be possible to stabilize the building with a whole lotta pallet wrap, but that doesn't help get any lifting points established, it just keeps the corners together.

[dgbldr]

I wouldn't try to lift it or drill any holes.

You didn't fully described the floor structure so I assume a regular joist+end joist type.

I would dig out a tiny bit of dirt under the end joist on one side and gently slide it (in the direction of the joists) onto large sheets of something like 1/8" sheet steel or similar. A few guys should be able to gently push it unless it's sunk into the soil. Just make sure to grade the soil flat under the sheet.

If it's too stuck in the dirt, do the opposite. Push the sheet under it.

[David Meiland]

It's got 2x4 joists under a layer of subfloor and a layer of finish floor. The walls appear to me to be sitting on the subfloor. Right now, the joists are sitting on pieces of 4x lumber but I think those 4x are only at one end, put there in an attempt to level it.

The plans call for new joists on new concrete, with the existing floor assembly over the new joists. The old joists need to come out.

I don't see how you could avoid separating the walls and roof from the floor, rebuilding the floor over new joists, and then resetting the walls and roof.

I also don't see how you could slide it. It's been sitting there for 110 years. I could sling around the bottom of it and pull it with an excavator but it would probably explode.

[dgbldr]

Better yet. So what's keeping you from punching out the end rims and sliding in a steel I beam next to each existing 2x4 joist? Now you have something to lift it with.

[dave_k]

I would do a shallow excavation around the perimeter of the structure. Just enough to give you some working room.

I would first protect the corners with a plywood L the full length so it doesn't get damaged by the welding you are going to do. Then get 4x6x1/4", 6x6x1/4" or whatever angle iron and slide it under the bearing walls leaving it cantilevered a foot or two at either end.

I would then cut to fit and notch angle iron to fit across the gable ends and weld it at the corners to form a solid bed.

Next I would use my steel bander (or borrow one from the lumber yard, I happen to have one for building column forms) and band around the entire structure. You may have to place a 4x4 at the center of each wall to get some tension on the bands. It may not be a bad idea to get 4x4 braces wall to wall on the inside, but you may have to send the unlucky carpenter who gets that job in with some food and a sleeping bag because when he's done and the bands are on there's no getting out.

I would then put bottle jacks under the cantilevered tails, jack it up, then tack 2 - 3/4" axle rods to the underside of the angle iron.

I would get stop collars and 12" pneumatic wheels and put a wheel on each corner.

I would then get some planks under the wheels, lower the jacks and roll it out of the way. Hopefully you aren't near a hill or you may have made the world's first heritage go-cart.

You just reverse the process putting it back, cutting instead of welding. The last inch or so, where you take out the angle iron is the tricky part. That takes some wedges, pry bars, hammers and a little ingenuity. As long as you haven't welded the bottom face you shouldn't have a problem.

[tod evans]

i`m in agreement with those who have suggested steel.......without touching the structure any other advice i could give would only be a guess.
factor in steel, a welder and a method of lifting either from above or below.