Limits to jacking a house?

[cgutha]

Its hard to describe the small details I noticed when I first look through the building. The plaster along the top edge of the stairway going to the basement had separated and overlapped itself by about a half inch. This had been painted over. The settling is slight, but now s the time to take it out.
Careful observation tells me what is old lumber and what was replaced.
The one pipe steam line was once a dry return system, but when they put in the "new" boiler, they buried the return under the concrete. There is a patch across the hallway.
Little clues like this tell stories. My opportunity is to read all the stories and decide what parts are going to be restored and which parts are updated. Obviously, we are not going to restore the bedpans. I suppose if I had them (they were sold on auction some years back) I could distribute them in each room, but I will keep the running water and update the electrical.
The rooms are 10x10, 10x12 and 10x14. while these were fantastic at the turn of the last century, they no longer meet the standards of today's guests.
The fire escape is also not original. I have finally decided (depending on cost) on what I want. A cement balcony with brick railings to match the building, an enclosed, external staircase that will also serve as security. I can not afford an elevator.
I have always been disappointed when I see additions to buildings that do not match the theme and architecture of the original building. Planning and careful selection of materials does not cost that much more. Many times it is cheaper.
ceg

[cgutha]

Assuming plaster weighs the same as concrete (144 lbs/cu ft) I started calculating the load on my beams. I also went to the next cycle of jacking. Looks like the post I was using on my jack is too lightweight. I need to get the heavier duty posts. Now I know how they will fail.
ceg

[phil]

this table shows "plaster on wood lath" as 8 lbs per square foot an inch thick and concrete as 12 ( or 144 per cubic foot) but "lightweight concrete as 8 so you might be close and maybe erring on the heavy side depending what you estimate the thickness of the plaster as. It's not normally an inch thick but perhaps more than 1/2"

http://minimotives.com/wp-content/uploa ... terial.pdf

[cgutha]

Wow. I remembered my user and password. Just an update: I revised the water level to use 1/2 inch PVC and fittings. The water flows much quicker through this as apposed to the 1/2 " PEX. Looks nicer too.
I have slowly raised the center of the building to within 3/4 of an inch. Haven't worked on it for a while. I guess I must be close enough because it doesn't bother me so much anymore.

There is no way to see one end of the house from the other, so I stretched the water level to three sides of the house in an attempt to see if the foundation is somewhat true to the world. It's a guess because I can't actually see where the foundation meets the floor joists except on the south wall.

My big project now is to glaze and paint the windows before any more panes fall out. I lost seven of them last winter.
Finding 36x34 glass is not as easy as I remember. I learned I could order custom glass, but those are double pane sealed with gas inside. The windows are already double paned with a one inch rabbit between. Part of me thinks I could order two of sets of double paned windows and end up with a r-8 sash. The cost is not that much different if I am replacing missing glass.

I hired a boom truck so I can get to the windows fairly easily. So far they need a lot of work.

By the way, thanks again for all your help.
ceg

[Gothichome]

Welcome back. Good to hear of your progress. Windows, if nothing else to do there's always windows. I to am doing a slow jacking of a floor. Some time in the distant past they undermined about two meters of wall support in the crawl space. Over time the area above the missing foundation had sagged about an inch. Been jacking little bits for six years. Getting there though.

[phil]

for the water level, I just picked up a roll of clear plastic hose about 1/4" diameter on the outside. I find it works ok. If you are using it a lot you can put a bit of food coloring in the water so it sired or whatever, a little easier to see.

I'd pick a benchpoint. then as Casey says just go around and mark references +/- in relation to the benchpoint. once you have those reference points it is easy to measure with levels, tapes and strings, plumb bob and lasers within each room. as you jack of course you will change the relationsip of certain points to the benchmark. the benchmark should be a spot near the site that isnt' going to shift so you always have that as a reference point to see how much you have changed things.

It's quite a task you have taken on with straightening such a building so you might need someone experienced with lifting brick and stone structures to help. obviously they dont really flex and it might take a trained eye to examine the stress points and how the load of the structure is being carried. around me we have guys that specialize in it and they have all the equipment for lifting and shoring like piles of beams that they use for the job and take away after.

It's possible to use hydraulic cylinders and some of them can work in tandem and lift proportional amounts by feeding an equal fluid amount of fluid to each cylinder.

I had to work on some engineering equipment recently. its like a hydraulic press only on a massive scale. they can put huge I-beams in there and bend them to analyze data on load. they have these little sensors that are about an inch long and they crazy glue them to various points of the beam. As they load the beam they measure stretch and shrinkage, not in relation to each other but these sensors are measuring the stretch and shrinkage of the length of the sensor, only about an inch. you can imagine what the stretch nad shrinkage over an inch would be , only microns. the sensors can make a graph on a computer so as they apply more load they will and record changes in length. when compared to what is expected they can tell what is happening to that beam in ways you couldn't see or measure otherwise. They can measure how the beam is stretching and shrinking at various points with loading and they use that data to calculate things like what load they can carry. once they know what the beam can carry without too much deflection they apply calculations for a safety factor.

i thin k most of this is to show the engineers how they arrive at set standards. perhaps they could tell for example how much weight is on an eye beam by measuring it's deflection and applying that data to a graph of known deflection rates.


recently they called in engineers to check the load carrying capacity of a lot of steel racking and things that were shop built. so the engineers charged lots and looked at things like data for all the steel members and in a nutshell they basically do the same thing. They calculate on paper what they think the thing will carry then apply safety factor so they can load them with about 1/6th of what it would take for the calculated failure. eventually the racking is given a maximum load rating and that is marked on the rack. commercial built racking is per-engineered so it is purchased with a known load rating.

a structural engineer would have more knowledge of how this all applies to your project. I guess you have responsibility to see it's done safely. of course we can pop in with ideas and suggestions but you might be in a position where legally you need some sort of engineers involved to make sure you aren't creating any potential for catastrophic failure.

[cgutha]

Update: I spent this summer adding sheetrock, plumbing, trying to complete half the second floor. Winter came early so I turned my attention to "Room 1": my apartment. We almost have the bath complete. I now have a new respect for tilers. I will take a few pics after it's completed.

The lifting project ended this spring when I started replacing the sheetrock. The building is within 3/4 side to center. given a 22 foot span and a hundred years, that's close enough. The pressure on the jacks were worrying me. Much of the warping was caused during past floods. Unless I wanted to flood the building again to unwarp the members while they are saturated ... no.

We came across a place above the dining room where a former psudo-plumber wannabe cut across ten feet of 2x13 floor joists to install a 4" sewer pipe. The building was near to collapse as floor joist also anchor the exterior wall.
I need to upload the pictures and file showing how we corrected this without damaging the tin ceiling below. It involves building a large beam and buying several eyehooks and nine come-a-longs. A week after this was completed, we purchased 100 sheets of 12x8 5/8 sheetrock. At 104 lbs each, I placed five tons of weight on this newly repaired floor.
Good enough.
ceg

[phil]

100 sheets of 12' that's a big reno! I'm glad to hear the leveling worked out. I keep having this funny cartoon in my head of an old house owner leveling his house and inching upwards. forward to the last frame where he's built basically what looks like high rise which still isn't level . I dont' know why I think of these things sometimes..

[Gothichome]

Ceg, great to hear of your progress, sounds like a lot of engineering concepulization going on to make it happen. Looking forward to the pics.

[cgutha]

I started the final structural project this week: replace the second floor interior bearing wall which runs the length of the stairway. This involves installing a temporary beam, removing the bearing wall (cobbled by many door, window and plumbing cuts.) then installing a permanent beam and rebuilding the bearing wall to hold the beam. Not a post and beam, more of a wall and beam. With a ten foot ceiling, I have room for a beam above the bearing wall.

Except...

As I completed the project downstairs, my wife, Cindy, is becoming more involved in sharing ideas with me. This is a good thing. She suggested combining two rooms to make a large open room (about 17 x 25 or 23x30 if one includes the hallways) This would overlook the stairway and landing with all its woodwork. It would also allow sunlight from two south windows to reach the stairway which is north of the center line. I like the idea. The bearing part of the wall will be two three foot walls. The effect of coming up the stairs seeing the open space should accent the stairs which is a primary feature of the building.

Alright, I have before and after pics of the one room. I will try to load them soon... or I will add the pics to my website when I get around to it.

ceg