I do not know. There are no known pictures of these. Why would they place iron grates on the north and west side but not on the sides facing the streets?
ceg
Limits to jacking a house?
Re: Limits to jacking a house?
I installed my water level and have a few tips (along with things I would not do again)
I had a bunch of PEX laying around. I would not use it again. Air gets trapped in them and takes forever to get out.
Instead, I would use Rigid PVC. attaching it permanently to the beams, slopping it toward the far end to allow the air to get out. Attach the clear vinyl hose to the ends of this. run it from below the top of the beam to about the floor boards. This is the "sight glass"
I used 1/2 inch but it still takes time for the water to seek its level. In my case, I have maybe a half inch of water pressure over the length of a hundred feet. It took two weeks to find its level.
I have a clear four gallon reservoir that I can adjust and refill so that the water level is even with the edge of the foundation.
I wish there were an accurate way of measuring the water level to the bottom of the floor joists. I used a tape measure and my eyeball. I record each of the measurements from the ends of my six beams. At this point, not knowing what I am doing, I am lifting only the one end of the beam that is one and a half inches low. the others are only one inch low.
I am using a 20 ton hydraulic bottle jack to lift the end of the beam so I can turn the permanent screw jacks one revolution a week. One revolution is about 0.16 inches. The house definitely groans when I do this.
further suggestions are welcomed
ceg
I had a bunch of PEX laying around. I would not use it again. Air gets trapped in them and takes forever to get out.
Instead, I would use Rigid PVC. attaching it permanently to the beams, slopping it toward the far end to allow the air to get out. Attach the clear vinyl hose to the ends of this. run it from below the top of the beam to about the floor boards. This is the "sight glass"
I used 1/2 inch but it still takes time for the water to seek its level. In my case, I have maybe a half inch of water pressure over the length of a hundred feet. It took two weeks to find its level.
I have a clear four gallon reservoir that I can adjust and refill so that the water level is even with the edge of the foundation.
I wish there were an accurate way of measuring the water level to the bottom of the floor joists. I used a tape measure and my eyeball. I record each of the measurements from the ends of my six beams. At this point, not knowing what I am doing, I am lifting only the one end of the beam that is one and a half inches low. the others are only one inch low.
I am using a 20 ton hydraulic bottle jack to lift the end of the beam so I can turn the permanent screw jacks one revolution a week. One revolution is about 0.16 inches. The house definitely groans when I do this.
further suggestions are welcomed
ceg
-
Casey
- Wizened and wise in the old ways
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- Joined: Thu Aug 20, 2015 5:34 pm
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Re: Limits to jacking a house?
Level is only valuable up to a point with jacking an old house, as it is reliant on how level the house is _globally_. If the whole house has settled lower on one end, for example, then using a level while jacking a floor is not going to give you the feedback you really need.
A fixed point in the context of this discussion is something immutable and outside the realm of floor leveling, like a chimney or exterior/bearing wall.
When jacking floors in old houses we make better use of string lines to make it flat/planar between the fixed points, whether the fixed points are level with themselves or not is really of consequence. If you are doing foundation work and raising the entire house, then a water level or builder's level/laser, etc.. is very useful.
You have to be able to separate in your mind the concepts of planarity and level.
Casey
A fixed point in the context of this discussion is something immutable and outside the realm of floor leveling, like a chimney or exterior/bearing wall.
When jacking floors in old houses we make better use of string lines to make it flat/planar between the fixed points, whether the fixed points are level with themselves or not is really of consequence. If you are doing foundation work and raising the entire house, then a water level or builder's level/laser, etc.. is very useful.
You have to be able to separate in your mind the concepts of planarity and level.
Casey
The artist formerly known as Sombreuil
Re: Limits to jacking a house?
Thanks Casey, I will try to understand this.
When examining the brickwork around the 440' circumference of the house, I see very little evidence of foundation settling. there are a few cracks here and there, but they show up in old photographs. so since they have not seemed to have grown in the past 50 years, I am not very concerned.
Correct me if I am wrong, but a string over the length of 40 or sixty feet sags, no matter how tight one pulls it. (Then again, the water takes time to settle over that distance.) in either case, I have walls that make a line of sight from one end to the other impossible.
I think what you are saying is that in a room, the floor should be flat and this is not necessarily level.
In my case, the bearing walls at the center line of the house have "punched" a divot or gully into the flooring. so that near the wall, the floor curves downward. This I wish to remedy before adding any cosmetic changes. The major cause of this is the fact that the bearing walls below are offset from the walls above. I assume that the warping occurred in the 63 flood when the floor joists became wet.
I also realize that if I support the bearing wall above, the warpage may remain until another flood soaks the wood to where it can warp back.
This being unlikely, I have another problem that must be addressed. some of the floor joists are damaged. Over time, some have sheared lengthwise. some are compressed at the sill plate. These need reinforced and supported. As the old adage says, "a stich in time..." For a few dollars now, I can reinforce the flooring so it can live another 100 years.
As for jacking, I assume the perimeter is intact and only the centerline needs reinforced and lifted. If I come within a quarter inch, it should be good enough. The building has lived this way for fifty years. Tuck the brickwork, shore up the center. The house is solid. It just needs a little attention.
This being said, I think I have missed what your experience is trying to tell me.
Please feel free to try to explain it further.
ceg
When examining the brickwork around the 440' circumference of the house, I see very little evidence of foundation settling. there are a few cracks here and there, but they show up in old photographs. so since they have not seemed to have grown in the past 50 years, I am not very concerned.
Correct me if I am wrong, but a string over the length of 40 or sixty feet sags, no matter how tight one pulls it. (Then again, the water takes time to settle over that distance.) in either case, I have walls that make a line of sight from one end to the other impossible.
I think what you are saying is that in a room, the floor should be flat and this is not necessarily level.
In my case, the bearing walls at the center line of the house have "punched" a divot or gully into the flooring. so that near the wall, the floor curves downward. This I wish to remedy before adding any cosmetic changes. The major cause of this is the fact that the bearing walls below are offset from the walls above. I assume that the warping occurred in the 63 flood when the floor joists became wet.
I also realize that if I support the bearing wall above, the warpage may remain until another flood soaks the wood to where it can warp back.
This being unlikely, I have another problem that must be addressed. some of the floor joists are damaged. Over time, some have sheared lengthwise. some are compressed at the sill plate. These need reinforced and supported. As the old adage says, "a stich in time..." For a few dollars now, I can reinforce the flooring so it can live another 100 years.
As for jacking, I assume the perimeter is intact and only the centerline needs reinforced and lifted. If I come within a quarter inch, it should be good enough. The building has lived this way for fifty years. Tuck the brickwork, shore up the center. The house is solid. It just needs a little attention.
This being said, I think I have missed what your experience is trying to tell me.
Please feel free to try to explain it further.
ceg
-
Casey
- Wizened and wise in the old ways
- Posts: 722
- Joined: Thu Aug 20, 2015 5:34 pm
- Location: Eastern WV
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Re: Limits to jacking a house?
The string also has the benefit of giving you a reading at any point along its length.
If you have a 40ft or 60ft expanse of flooring, point taken.
You can use your water level (or laser) to establish benchmark readings at the corners of the structure which will tell you how globally level it is. Then you can do the same thing in the basement(?) to benchmark the interior posts or walls that are carrying the floors above. If no basement, you can do the same thing at interior walls/points throughout the 1st floor that were not given values outdoors. Then you enter all the values onto the plan; for your purposes the highest point should be "0" and the deviations lower than it entered like -.5" , -.75", -4.375", etc. Then you have a roadmap to follow and figure out where and how points could be raised and re-supported.
If the line of bearing is offset, you probably need to add new support under it that _is_ in direct line.
I have seen plenty of houses with a divot next to a door frame. The door frame studs are taking a massive share of the load above, and are supported by nothing more than subfloor.
At some point you get into structural engineer territory, like if you need to add new posts and footings to take point loads. We can't do that online.
Casey
If you have a 40ft or 60ft expanse of flooring, point taken.
You can use your water level (or laser) to establish benchmark readings at the corners of the structure which will tell you how globally level it is. Then you can do the same thing in the basement(?) to benchmark the interior posts or walls that are carrying the floors above. If no basement, you can do the same thing at interior walls/points throughout the 1st floor that were not given values outdoors. Then you enter all the values onto the plan; for your purposes the highest point should be "0" and the deviations lower than it entered like -.5" , -.75", -4.375", etc. Then you have a roadmap to follow and figure out where and how points could be raised and re-supported.
If the line of bearing is offset, you probably need to add new support under it that _is_ in direct line.
I have seen plenty of houses with a divot next to a door frame. The door frame studs are taking a massive share of the load above, and are supported by nothing more than subfloor.
At some point you get into structural engineer territory, like if you need to add new posts and footings to take point loads. We can't do that online.
Casey
The artist formerly known as Sombreuil
Re: Limits to jacking a house?
Thanks Casey,
As for structural engineering, I understand. At present I am trusting the existing basement floor to take the load. I suppose that if, in the future, I see signs of failure, I will have to install interior footings under the various posts. for now, I am not.
Your description of the string with benchmarks describes my task. I am adding steal beams under the bearing walls to support them directly. Also, your description of the divots at the door posts (and added beam posts) is exact. This is why I am reinforcing and supporting the floor boards from underneath.
The next questing is in the lifting. Let's say I have a fairly smooth arch as a bow in the floor. do I lift the ends at the same rate as the center or divide the distances so everything reaches zero at the same time?
For example. The greatest measurement is 1.2 inches. At the ends, I have only a half inch. If I raise the center at 0.1" a week, it will take 12 weeks to bring the center to zero. But if I lift the ends the same amount I will see them in position in only five weeks.
It seems to me that it is better to lift the ends 0.05 inches each week so the entire floor comes to zero at the same time. Otherwise I am introducing a kind of ripple that may be foreign to the house causing other damage.
This of course is theory and we all know that reality acts in uncertain ways.
ceg
As for structural engineering, I understand. At present I am trusting the existing basement floor to take the load. I suppose that if, in the future, I see signs of failure, I will have to install interior footings under the various posts. for now, I am not.
Your description of the string with benchmarks describes my task. I am adding steal beams under the bearing walls to support them directly. Also, your description of the divots at the door posts (and added beam posts) is exact. This is why I am reinforcing and supporting the floor boards from underneath.
The next questing is in the lifting. Let's say I have a fairly smooth arch as a bow in the floor. do I lift the ends at the same rate as the center or divide the distances so everything reaches zero at the same time?
For example. The greatest measurement is 1.2 inches. At the ends, I have only a half inch. If I raise the center at 0.1" a week, it will take 12 weeks to bring the center to zero. But if I lift the ends the same amount I will see them in position in only five weeks.
It seems to me that it is better to lift the ends 0.05 inches each week so the entire floor comes to zero at the same time. Otherwise I am introducing a kind of ripple that may be foreign to the house causing other damage.
This of course is theory and we all know that reality acts in uncertain ways.
ceg
-
Casey
- Wizened and wise in the old ways
- Posts: 722
- Joined: Thu Aug 20, 2015 5:34 pm
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Re: Limits to jacking a house?
You cannot directly (immediately) take a hump out of a floor just by raising the ends of the joists, as the joists will be bowed for a long time, and lifting the ends will also lift the center (unless you stack sandbags to hold it down. You can really only lift until the weight is off the center bearing (whatever created the bow in the first place by not settling with the outside walls.)
Unless you can set a piece of steel (I-beam) and bolt the joists to it, anchor the steel beam to the foundation, then you can force the joists straight because they are prevented from lifting as they will want to do.
If I misinterpreted your description, I'm sorry.
Casey
Unless you can set a piece of steel (I-beam) and bolt the joists to it, anchor the steel beam to the foundation, then you can force the joists straight because they are prevented from lifting as they will want to do.
If I misinterpreted your description, I'm sorry.
Casey
The artist formerly known as Sombreuil
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phil
- Has many leather bound books
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- Joined: Tue Aug 18, 2015 6:11 pm
- Location: Near Vancouver BC
Re: Limits to jacking a house?
If a transit is useful I think the older ones are pretty cheap because the professional surveyors all have moved to digital ones now.
a laser level might be handier. even a cheap one makes a perfectly straight line. In Italy all the street kids were selling these laser pointers. they just run on two AA batteries but unlike the typical red ones they sell in the pet stores these are green and it'll go 4 miles. the beam is so bright you can clearly see it from the dust particles in the air, not just the light spot. .
Just make sure you have yourself covered with more than enough blocking just in case something dramatic happens. It sounds like you are making some pretty significant changes to how the weight is supported. I think I'd be tempted to stop once I got close but only you can be the judge of how level you can make it before you have unpredictable things happening to the structure.
It is really interesting to hear about your progress. If I could raise my house so the basement went from 6'4 to 6'7.. I think I could put in a legal basement suite which would provide security for retirement, but as much as I ponder it I can't decide if it would be better to lower my floor or raise the chimney and the house , or loose the chimney. That 3 inches would increase the value 100 thousand. maybe it would be more like a foot if I raised it I'd go to 8' but the sewer is already close to the height of my basement floor so I could only go down so far without pumping it . I have no issues with storm water as I am on a hill so there's no chance of flooding.
As it is now it's my workshop and I think I've pretty much decided I can't add the cost to my already heavy mortgage so I'm just doing what I can to restore what's there but the idea of (lifting) it won't leave my head. Lots of the houses around me are getting moved about and lifted because the real estate is high. usually they loose the chimney and the wood windows and they often just demo the foundation and build a new , higher one. what's left is a big house but not so many historic details. I think I'd be a bit more brave if I wasn't so scared of unknown costs from inspectors, engineers and the unknown hoops I might need to jump through to get where I'm going.
at least when I sell the potential will still be there and I guess that has value, and I'm only one man, but a suite would sure help the budget.
Phil
a laser level might be handier. even a cheap one makes a perfectly straight line. In Italy all the street kids were selling these laser pointers. they just run on two AA batteries but unlike the typical red ones they sell in the pet stores these are green and it'll go 4 miles. the beam is so bright you can clearly see it from the dust particles in the air, not just the light spot. .
Just make sure you have yourself covered with more than enough blocking just in case something dramatic happens. It sounds like you are making some pretty significant changes to how the weight is supported. I think I'd be tempted to stop once I got close but only you can be the judge of how level you can make it before you have unpredictable things happening to the structure.
It is really interesting to hear about your progress. If I could raise my house so the basement went from 6'4 to 6'7.. I think I could put in a legal basement suite which would provide security for retirement, but as much as I ponder it I can't decide if it would be better to lower my floor or raise the chimney and the house , or loose the chimney. That 3 inches would increase the value 100 thousand. maybe it would be more like a foot if I raised it I'd go to 8' but the sewer is already close to the height of my basement floor so I could only go down so far without pumping it . I have no issues with storm water as I am on a hill so there's no chance of flooding.
As it is now it's my workshop and I think I've pretty much decided I can't add the cost to my already heavy mortgage so I'm just doing what I can to restore what's there but the idea of (lifting) it won't leave my head. Lots of the houses around me are getting moved about and lifted because the real estate is high. usually they loose the chimney and the wood windows and they often just demo the foundation and build a new , higher one. what's left is a big house but not so many historic details. I think I'd be a bit more brave if I wasn't so scared of unknown costs from inspectors, engineers and the unknown hoops I might need to jump through to get where I'm going.
at least when I sell the potential will still be there and I guess that has value, and I'm only one man, but a suite would sure help the budget.
Phil
Re: Limits to jacking a house?
Casey: That hump took fifty years to develop. I suspect it will take that long to take out. I just want to shore up the bearing wall so it does not settle any more. Take out some of the droop so it will last another hundred years. We both know that "perfectly level" is not practical. It is that I found some "Warning signs" when I removed some of the walls and inspected the joists. These must be reinforced as they are close to failure / catastrophic failure.
Phil. I do not know your house, but if you have a stone foundation like I do, I would not touch it. Dig most of it down. The plumbing (toilet) can stay on the higher level just step up to the original level for the water.
This weekend is supposed to be warm. The time for planning is over. Soon the work begins. Too bad. We had a home show this past weekend and I have not drawn up the new ideas for the rest of the house.
Solved is how to build a handicapped entrance for the main door. (I need to change the exterior stairs to the basement so the handicap ramp overlaps the basement entrance. The basement stairs then goes to the north instead of the south. Too bad, too. Those stairs are in good condition and original.)
I solved the fire escape / security issue. An exterior enclosed stairway to the NW of the building can allow occupants onto the balconies and stay locked to prevent unwanted guests. The balcony railings can be brick matching the existing brick making it look as if it was part of the original building. I wonder what that will cost. Dreams are cheap.
ceg
Phil. I do not know your house, but if you have a stone foundation like I do, I would not touch it. Dig most of it down. The plumbing (toilet) can stay on the higher level just step up to the original level for the water.
This weekend is supposed to be warm. The time for planning is over. Soon the work begins. Too bad. We had a home show this past weekend and I have not drawn up the new ideas for the rest of the house.
Solved is how to build a handicapped entrance for the main door. (I need to change the exterior stairs to the basement so the handicap ramp overlaps the basement entrance. The basement stairs then goes to the north instead of the south. Too bad, too. Those stairs are in good condition and original.)
I solved the fire escape / security issue. An exterior enclosed stairway to the NW of the building can allow occupants onto the balconies and stay locked to prevent unwanted guests. The balcony railings can be brick matching the existing brick making it look as if it was part of the original building. I wonder what that will cost. Dreams are cheap.
ceg
-
phil
- Has many leather bound books
- Posts: 4616
- Joined: Tue Aug 18, 2015 6:11 pm
- Location: Near Vancouver BC
Re: Limits to jacking a house?
I remember building an addition with my dad ( former carpenter) as we pulled joist from the load he eyeballed each one to see which way it twisted and placed each one with the crown up. In time the floor might sink a little in the middle so he said it is favorable to have the crown up. depending how straight the original pile of lumber was it may have had a hump from when it was originally built.
i noticed the attic floor in my house is also crowned. when I cut the baseboards I had to take quite a lot out of the middle to fit them against the floor. i don't' know if this warp was there from the beginning but I have no urge to try to straighten it. The rest is plumb and level.
my house is more conventional , built 1924 with a concrete perimeter foundation about 2 feet tall. I could jackhammer the floor in about 10 foot square sections and lower it that way, underpinning the original footings. i don't want to loose my fireplace and if I lifted the house and not the fireplace the firebox would be too low, and lifting the chimny sounds scary. my sewer is a foot above the basement floor but I dug and ran new pipe so sloped it as little as I could and that got me near to the house and a foot or two lower. . I had planned to dig under for a toilet when I did out the storm drains. anyway lets keep this thread about your house I have a habit of rambling and it's a good thread.
Phil
i noticed the attic floor in my house is also crowned. when I cut the baseboards I had to take quite a lot out of the middle to fit them against the floor. i don't' know if this warp was there from the beginning but I have no urge to try to straighten it. The rest is plumb and level.
my house is more conventional , built 1924 with a concrete perimeter foundation about 2 feet tall. I could jackhammer the floor in about 10 foot square sections and lower it that way, underpinning the original footings. i don't want to loose my fireplace and if I lifted the house and not the fireplace the firebox would be too low, and lifting the chimny sounds scary. my sewer is a foot above the basement floor but I dug and ran new pipe so sloped it as little as I could and that got me near to the house and a foot or two lower. . I had planned to dig under for a toilet when I did out the storm drains. anyway lets keep this thread about your house I have a habit of rambling and it's a good thread.
Phil