I just spent the better part of the last couple months raising an old house, its 1920's vintage and has an updated foundation that was sunk about 3 inches in some places, anyhoo, iv raised her back up to level and "cold welded" some concrete patches between the new wood that I replaced and the old foundation that has sunk into the ground, the house had no gutters and will have a french drain system with four feet of slanted sidewalk alll the way around so this will not happen again -- the original foundation is aprox. three feet into the ground, This ground is rock stable,,, Till it gets wet, then it turns into baby poop,,,, anyways, im confident that I will get this place to drain and it did take apox. 90 years to create the mess it was in -------
Now for the paradox, I want to use a Tamper (ground compactor) around the parimeter of the house to get the ground good for the sidewalk, I already have a fair layer of roadbase there but am concerned about all the vibes sinking the foundation further, If I loose a quarter inch its no big whoop, if I loose a half that would suck,,,,,,,,, I couldnt tamp it while I had it on Jacks cause where I had to lift was sketchy enough,,,,,,,,
Anyone who has any compacting experience (I do have some) will tell you that it can be a double edge sword, anotherwords, you get a few good hits in and it will actually go down far enough to keep the house from sinking further, In fact, its actually possible to raise a light house this way, Iv raised sidewalk using one, But, by the time I got this house up to where i wanted it it was under extreme load due to the lumber being in its old position for quite sometime (even though I wetted the floor joyces dailey while jacking) So, all the vibes on the outer parimeter could cause the foundation to sink, weve had a ton of rain here lately and this is givng me some major concerns.
So forget the math, this is kinda a fly by the seat of your pants one as I only mentiond a fraction of the variables involved, Question, what do you guys think the outcome is going to be and Why?, and do you think its worth it to drive some deep ass stakes close to the foundation ,,, maybe put "pins" out of them and to the foundation for measurement, do a few hits and see what happens?
I had to do allot of work on the outer parimeters, compacting is a must as I want to keep a precise drain angle to the concrete sidewalk, If I dont compact the walk can eventually change slant and funnel water into the foundation....