Limits to jacking a house?

[cgutha]

I have finally installed a beam under a sagging support wall. I had a friend once tell me that a quarter inch a week is the limit for jacking.
Do any of you have experience in jacking /straightening a house? What is the limit I can jack without causing damage? Of course I will watch the plaster. It will tell me if I go too far too fast.
ceg

[phil]

I was speaking to a carpenter a month ago about the possibility of raising my house or lowering the floor. I'm scared of lifting the fireplace and don't want to take it out. My sewer has it's limits. my basement is about 6'4 so a few inches would make a big difference. Ive been going back and forth and part of me just doesn't want to take on the cost although it would increase the value. anyway he said 1/8th per week or something but I think he was just speaking figuratively. in other words slowly. if you are leveling the floor it's obviously going to be twisting and going slowly somehow makes a difference in allowing plaster and things to relieve their stresses.

my dad was lifting a house and hired contractors. He was already a carpenter so he had good sense of what was going on. they called him at work and asked if he wanted it straightened or just lifted. he said straighten it. I remember him saying he had wished he had said just lift it because it cracked everywhere and he had lots of repairs to do.

I see lots of houses around me getting lifted and they seem to like to just pretty much gut the house and raise it right up on timbers high enough to get machinery under, then finally set it down on a new foundation. It's always to put a suite in and increases value but most get the whole treatment with new windows drywall insulation new plumbing and wiring etc.

[Sinoed]

Lifting a house is incredibly expensive. When I was buying mine I made an offer on a small cottage in town that seemed to be a good deal because of the location. The catch was the "crawl space" under the tiny house, which was sand and slowly collapsing. This also happened to be where the furnace and a few other mechanicals were located (not good).

Putting a new foundation under a building is fairly common in the area (some families now have "million dollar" cottages) because demand for lakefront property has driven prices through the roof. I called a well respected contractor for an estimate to lift the house and install a full basement which convinced me to walk away. The house was a bungalow, less than 1000 square feet on a large level lot with no obstructions and the price tag was $50k and "possibly higher" depending on what they found

In a historic home I'd also be worried about cracking plaster, warping doorframes etc. I think the key is to just go really slowly and carefully. I'm not sure how you can measure the stress on the walls but I think you're right the plaster will tell you. I don't know if there are "limits" other than the obvious ones that you'll have for supporting foundation walls and beams?

[phil]

Obviously if it were a perfectly straight even lift you wouldn't be introducing nearly the stress that straightening or leveling would. A lot might have to do with your equipment. a company that lifts houses might have such items as several hydraulic cylinders which are fed fluid at constant rates resulting in a straighter lift. at the opposite end of the scale you may have a guy with a bunch of screw jacks. They could be turned at a uniform rate as well. also before the house starts moving there are going to be some supporting points that compress a bit more than others.

maybe a few markers could be anchored into dirt on the circumference outside the house. that might give you reference to weather the house is actually moving or compressing? once it starts actually moving the rate would be proportional to the number of turns of the screw jacks but before that you'd have some degree of compression in your blocking etc.

The part I find scary isn't the lifting but the cost of involving engineers and city inspectors. I know it's a necessary evil just like police but sometimes they have a habit of making something seemingly straight forward become a rediculous amount of red tape with no concern for cost. I often think I could just dig down a 10' x 10' section at a time and pour a new floor with some rebar and underpin the existing foundation with a new footing either on the interior or right underneath what exists.
being kind of chicken of the costs I'm slowly finishing my basement walls and ceiling with insulation and drywall. I don't suppose it limits the fact that it could be lifted or dug out. but maybe walls would have to be opened to some degree. If my cash flow was a bit different I might try a different approach. I often visualize the Hogan's Heros method of discreetly parting with the material from their secret dig

In my case I could also enlarge the house or build a garage. since I suspect it will become legal to build lane way houses. I like the idea of leaving the existing structure and making a separate rental in the back yard. Im really not in a position to go too huge or too fast so my choice is just to fix up and restore what's there and one day a new owner will see the potential to do more. I would love a garage but even that seems risky. Id' hate to build it then wish I'd gone to the lengths required to have a rental house in the back yard on top of my garage.

I was reading about a couple in my area the approached the city with a proposal where they would add a floor to their house and in return they would make the switch to heritage status which would limit any further reno's. It sounded like a novel idea. I m not sure what the outcome was.

[Nicholas]

Had mine jacked, apparently someone tried in the past, there were old rusty screw jacks under the house with stacked cinder blocks and bricks.

One side under the bathroom and adjoining bedrooms had about a 3 inch slope, the 1940 installed bathroom had unsupported walls. I called in the professionals, who had a 6 week waiting list.

After a week of prep, with 14 concrete footers, 8 piers and 6 adjustable piers, sill replacement, sister-ed up PT beams, they used hydraulic pump jacks, with a guy on each one, and a guy inside with a long level running from room to room yelling instructions.

That whole op took 20 minutes. Yes, walls walked, small spaces appeared. Doors, which were replaced years after the house was already sagging, changed back to where they should be. The front porch, which had a slight lean, straightened itself out.

Scary. That was almost a year ago, March, and I am still watching for new signs of settling in. House still standing.

Total cost, 7300 dollars.

Click on "BumbleBee House" below for a couple pics of that operation

V

[cgutha]

Wow! Thanks guys, I better give some details.
The place is roughly 44' x 66' three story brick building built 1906. The long dimension faces south. I do not know who the architect was. But Mr. Berry built it. Hence the name Berry Hotel, Velva ND.
Currently, the double hung windows work. The doors close and the transits above the interior doors operate. the woodwork appears original and escaped the 60's trend of being painted. As near as I can tell, the perimeter of the building is solid and has not settled. The foundation is stone. maybe two feet thick. Maybe three. The building sags toward the east-west centerline about 1 1/2 inch in 22 feet.
The building is divided into quadrants. On the first floor, the southeast quadrant contains the Lobby, about 25 x 33. The Southwest contains the Dinning Room, about 33 x 22, The Northeast is a living area, formally the parlor and a few other smoking rooms. The Northwest features the stairway, kitchen and originally, two bedrooms.
In the basement, below the lobby is a large room where traveling salesmen held their meetings. Below the dining room is the washing room. The wash machine consists of a single electric motor, overhead shaft/pulley system, belts, barrel washer, ringer, pump, pre-rinse and a few other parts. This still moves and could be operational with a little glue on one of the wooden pulleys.
The northwest held the coal room and boiler, the Northeast holds the cistern and room No. one. Later turned into a wide cellar.
The first thing I noticed when I tried measuring and drawing the floorplan is that the walls do not line up.
Descending the stairway into the basement, one faces east. A hallway leads to an exterior door about 33 feet through the eastern wall/exit. This hallway is 53 inches wide. To the south the original (2x8) old lumber, double studs, 16 o.c. are exposed. Above the header, the 2x11 (actual) floor joists meet and overlap by three or four feet. Someone placed a 6" wide engineered beam to the south of this wall with floor jacks every four feet. Do not be mislead, this is not the bearing wall. The only thing above this wall is the lobby desk installed in the 20's.
To the north of this hallway is the two foot thick cistern wall. The cistern drops below the basement floor level another three feet, the wall is about six feet high. 2x4 studs extend from the top of the wall to the floor joists above along the south edge of the wall. on the floor above is a large ripple in the floor.
I removed the siding covering the cistern.
The cistern was poured incorrectly. about four feet from the west end of the wall, it curves so that the western portion under the sill plate is missing. Someone tried to cover this up with a 2x4 holding the plate in place. Close inspection of the top sill plate, floor joists, and other members show a variety of stress such as warping, compression, sheering etc.
A former electrician drilled holes next to the wall on the first floor. The wall above sits 13 1/2" to the south of the cistern wall.
This is where I placed my first beam after reinforcing the floor joists.
The floor sages to the center as I said, but then because someone jacked the south hallway wall, straightening the lobby floor, the floor upstairs suddenly slopes that 1 1/2 inches in four feet.
"But wait there's more!"
The north wall, where the wine cellar is, was replaced with new lumber. The carpenter who replaced this did not notice that when he removed the old lumber the floor sank an inch. he cut the new lumber to match the hole.
I placed a second beam under the load bearing wall above.
Now I am ready to jack this portion of the house.
But there is more. The load bearing walls upstairs split and go around the stairway. this will take two more beams of longer length. but the method will be the same. Support the walls directly.
ceg

[phil]

wow this sounds like a more complicated project than I thought! I hope it's going well and that you are safe. We have almost no brick buildings here and you are faced with some much different circumstances than just leveling /straightening a stick built home!

I'm sure you know this but maybe some readers don't. One tool that is very helpful is a water level. Just take any piece of clear hose and fill it with water. get any bubbles out. raise either end. the water in the hose will always find the same level at both ends of the hose. you can make one point a benchmark. I find it handy when trying to level a wall or patio outside or to do awkward measurements like the rise of a staircase. Trying to find the same point of reference inside and outside the house might be another example. I have a transit but I find this method is often easier, especially when I'm working alone. even a green garden hose will suffice but best to use 1/4" plastic tubing and you can add food coloring to make it easier to see.
good example: leveling a brick patio. make a benchmark- just a stick pounded in the ground with a line a foot above your surface. tape the hose to that stick and make a mark. -call that mark your benchmark. Now use another stick a foot long you can put that on top of any brick and reference the water level. If it is level with your benchmark it should also be level with the top of your stick and you can move that one around to any point on the surface. This way you aren't compounding any inaccuracies like you would if you used a carpenters level.

[Casey]

The plaster wants to maintain its shape; it's shape (and weight) will limit how much your jacking can accomplish. I once did a project that entailed jacking 7" of sag out of the middle of a house, all three floors. It could only be done by gutting the house of the overbearing plaster partition finish.
Casey

[cgutha]

Phil: great idea! I could place one end of the hose by the foundation that I know is correct and other levels between the various beams and end of beams. No guesswork.
I am assuming that the foundation is stable. Only the wood framing inside needs adjusted.

I measured the beam needed on the north of the stairway. This is 25 feet. I do not think I will install that by myself.
South of the stairway is a 33 or so foot long bearing portion. I need to remove the sewer line to install this. (Good. That plumber did me no favors.)

Casey: The plaster has been screaming at me. Last winter (2014-15) was the first winter without heat. After I started renovations on the first floor, I stopped because I noticed movement. When the cracks line up again, I will know I am close.

My original thought was to gut everything on the second and third floor. However, I am not so certain now. The walls are not that bad and I am afraid of removing the woodwork. (more specifically, I am afraid I do not have the skills to put it back)

It may be my imagination, but I no longer feel vibration when the train goes by.

Some of the damage is old, 40 or 50 years or more. The building stands.
Some of the damage is recent. I think I caught it in time.

More info: This building holds many secrets. Built in the era of Frank Lloyd Write, it is not a Write building. However, some of his influences may be incorporated. This is given in the fact that the bearing walls do not align between floors. (or someone else came along and massacred the building) I believe I would not have a problem if the 1910 plumber had not chopped through my floor joists.
One of the clues I have noticed is that wherever a north-south wall is above the ceiling, I have a double ceiling joist. By the way, did I mention that the ceiling joists above the first floor are 2x14 actual?
There a metal lags going into the brickwork every 4 feet or so. These keep the walls from bowing out.

ceg

[phil]

"It may be my imagination, but I no longer feel vibration when the train goes by."

I had one of those spin washers. When it was ramping up in spin speed it would hit a certain speed where the natural frequency of that point in the house matched the natural frequency of the spinning action. At that certain frequency it would shake the floor in the living room which is at the opposite end of the house! there was nothing structurally wrong.

a nearby railway would also have a natural frequency relating to the speed of the cars passing. You might by chance find that even somewhat subtle changes in the way the structure is supported affect the building's natural frequency and the result could make a remarkable change.

an example is a branch on a tree, when it's windy it will move back and forth at it's own natural frequency. longer branches have a lower frequency.

I used to work on huge printing presses and sometimes I would have to troubleshoot issues with bearings and things, sometimes I'd find weirdness because there are a lot of rotating parts and I'd see for example marks on the printed image that were the result of stresses from natural frequencies of parts combining in unfavorable ways. one effect is a shock through the sideframes of the entire machine and that can cause marks across a printed image making the product unacceptable. it can get quite complicated if you try to calculate it but you do see the effects in the weirdest places if you look for it.

I remember one machine ( poorly) installed on a wood floor. I could eyeball down the sideframe of the machine and see it bouncing and twisting and of course destroying itself. It was because the frequency of the floor just happened to match the frequency of vibration of the machine. Forces like that might contribute to settlement of load bearing parts. It's an interesting science and perhaps if you have the opportunity to consult with a structural engineer he might be able to shed more light on how the railway affects your foundation. Everything has it's own natural frequency but there is a bit of hit and miss as far as how those frequencies can combine.

it's like pushing a kid on a swing. you have to push at the right moment to increase his height. Several well timed pushes combine to make him go higher each time so these small efforts are sort of amplified. Pushing at any other frequency would upset the motion. you could push at half the speed ( every second swing)and that would have a similar effect. changing the length of his chains would change the kids natural frequency.