move a house....

Fast fact: my house weighed 42,000 pounds (21 tons)-- this was after the roof/attic space was removed.

Many people are amazed to learn that you can move a structure as large as a house. Actually, it's not really that complicated, in theory! Structural movers can move an astounding array of structures, like mansions, brick buildings, castles, and light houses, not to mention many other large objects, like airplane parts, arctic drills, and huge machinery. House movers also routinely jack up houses to repair or replace foundations, to either fix structural problems or to add another story to a house to make it larger.

How do they go about raising and moving a house? Here is a layman's explanation of the process used to move mine.

First they used a sledgehammer to punch holes in strategic places in the foundation. Then they slid in huge steel I-beams through the holes, all the way under the house. The I-beams run perpendicular to the floor joists, such that they take the place of the house's stationary underpinnings (whatever those may be-- wood beams resting on posts, or just the sill plates sitting on top of the foundation walls, or both).

Houses that have additions where the floor joists run in more than one direction, or where the levels of the floor change, or just large houses, are more complicated and require more I-beams and cross-supports. This house was pretty basic, it required two long I-beams running front-to-back, and two more short ones running side-to-side to support the back addition. The short beams sat on top of the two main beams. In places where the floor joists were crooked, they just used shims to make sure the house was supported all the way across the beams.

Once the I-beams are in place, the house's connection to its foundation is severed. In this case, the house had previously been raised to add a new foundation underneath it. So, its connection with the sill plates was poor-- only large nails, which pretty much came out by themselves. Once the house is detached from the foundation, it's ready to raise.

They raise the house using multiple hydraulic jacks under the beams. The jacks are centrally controlled, such that the house can be raised level (with itself), or its horizontal plane can be modified (which would often be the case with a house being raised to fix a problem of not being level to the world). Once the house is up off the foundation, cross beams are placed under the main beams, and dollies go under those. My house had three 8-wheeled dollies underneath it; one under the back addition, and two under the main part of the house. The dollies are chained to the beams.

Once the house is up on the dollies, a large truck can tow it by attaching a long tow bar to the front dolly. Bob Cook decided to tow this house backwards, so he could most easily pull into the destination site with the house correctly oriented. So, he pulled the house out into the street, and "spun" it right there on 5th Street, by manipulating the two bar and also using his boom to get the house facing in the right direction. Towing down the street was easy, but slow-going, because even with the street cleared via no-parking signs, it was barely wide enough for a 28-foot-wide house. Bob was required by the city and county to hire a pilot company, so we had several pilot cars and motorcycles clearing the way. While we were moving the road was completely closed due to the width of the house. The flashing lights attracted a lot of attention in the middle of the night!

Once we got to Ed Stocker's cow field, going got a little tougher. Though the field was summer-dry so the house didn't sink at all in the dirt. But he grass was wet with dew, which often made it impossible to tow the house like was done on the road. When this happened, they stopped, unhitched the house, and used the crane to pull the house over the small hills and dales in the field (the crane boom gives just enough upward tension to help the house along). I've heard tale of houses being moved through fields in the winter, where they sink up to the I-beams in mud, so it can be done! In soft dirt situations, they can lay down cribbing (crisscrossed blocks of wood) or steel plates to help distribute the weight as they drive over the soil.

The reason we had to drive through Ed Stocker's field was to get past an obstacle-- the BNSF train trestle. Where it crossed the road was too narrow for the house to pass, but the concrete trestle pillars were spaced wider apart in Ed's field. So, Ed was kind enough to let us drive right through the cows in the middle of the night (they were curious, but kept their distance), and kept us company the whole time too! There was plenty of width to spare under the trestle, but height was close-- about a foot clearance at the top, as can be seen in some of the photos. This was part of why taking the roof off was necessary.

Once the house reached the destination site, the crew parked it in the driveway and went home to sleep. It took four hours to travel about 4.5 miles, and most of Bob's crew were on their feet that whole time, running alongside the house, crawling underneath it, hitching and unhitching the tow bar, attaching and detaching the boom, removing and replacing Ed's fencing, and doing other work to keep the move rolling. So, needless to say, they were tired! After some rest, the returned later the next day to put the house in the foundation hole.

House movers can adjust the house in its final location very accurately, down to the inch, if need be. I didn't need to be that picky, so it was quick to align it in the foundation hole and verify it was roughly 15' from the property line like my site plan described. Once it was in place, they used the same jacks to raise it up again. As its raised, they stack "cribbing" underneath, which looks similar 3' sections of railroad ties stacked like you would objects in a "Jenga" game. This house had four sets of cribs under it, more or less centered foursquare under the main part of the house; and the back addition of the house was just cantilevered off the main beams in midair.

We jacked it up about 7.5 feet high, to make it easy to build the foundation underneath it. This part always confuses people, why you don't build the foundation before the house is relocated to the site. There are three  good reasons: 1) you would have to have huge holes in the foundation in order to drive the dollies through when "parking" the house and 2) old houses are usually pretty crooked, and may become more so after being moved. So, it makes more sense to build the foundation right underneath the house, to be sure you are plumb underneath it; versus trying to draw a very accurate foundation plan describing all of the idiosyncrasies to make sure the foundation and house match in dimension and shape in the end! 3) The house is sitting on steel I-beams, so special pockets need to be built into the foundation to accommodate these once the house is lowered down. It's easiest to design these pockets when you know exactly where the beams are.

While the house was jacked up, Jackie did a lot of work underneath it to repair dry rot in the floor joists and even the subfloor. This is a good time to address this issue, while there is plenty of room to walk, see and work underneath the house; versus doing it after it's on the foundation would be less convenient.

After the foundation is poured, different raisers use different designs to attach the house to the foundation. The system we used was to insert J-bolts in the wet concrete, about 2" in from the inside walls of the foundation, and sticking up higher than for a normal house. After the concrete cured, Jackie put down a treated sill plate on top of the walls (with holes drilled to fit over the J-bolts), and a second plate attached to the house. He used a plumb bob to mark the location of the J-bolts on this top plate, and drilled holes in that so the house could sit down over the bolts. This is called a double sill plate system.

Once the house is set down, you just reach in and screw the nuts on the J-bolts, and the house is attached to its seat! The only key is to remember to "look up" when putting the J-bolts into the concrete, so that you don't accidentally align them with a floor joist or a beam, which would make it impossible to reach in and put a nut on the bolt afterward! Fortunately, the county didn't require further earthquake strapping (as would be required on new construction) as this would have made us have to remove a lot of siding, damaging the historic exterior.

Setting the house down is the same process as jacking it up, only in reverse. They use the jacks to slowly lower the house, and then take all the cribbing out through the crawlspace entrance. Remember that there are pockets in the foundation into which the I-beams are lowered once the house is set down. After the house is resting on its new walls, the beams are slid out from underneath using rollers. In the end, screen is attached to the pockets in the foundation, converting them into vent holes. Because of this, we tried to make the pockets the same dimension as the rest of the vents, to have them match aesthetically.

That's all there is to it!

For some interesting information on house moving, check out the Nickel Brothers' Website.

This site was last updated 12/05/08