OP
tkappeler
Platinum Member
That is correct.
New Home Begins
- Thread starter tkappeler
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That is correct.
sdkubota
Platinum Member
It is difficult, if not impossible, to achieve a minimum of 95% compaction with a smooth drum roller on soil in 8" lifts. If they have a sheeps foor drum that is different but an 8" lift is still difficult and usually ends up as a 12" lift. I would pay for a geotechnical firm to take some soil density tests. I know I will get the poo, poo but this is my expertise and you will experience future settlement if adequate density is not achieved. Maybe 10% of contractors actually understand what compacting soils mean because they have had to do it on Federal, State, or Local projects where it was required and tested. The rest have zero clue.
dave1949
Super Star Member
Thanks for the pics and documenting the wall process. Sure helps for those of us not familiar with that building technique.
Sinecure
Bronze Member
I know you have a ton of stuff going on with the build, so thanks a lot for posting the pictures and describing the process.
It is interesting to follow a technique that one is not familiar with. Good luck with the build!
It is interesting to follow a technique that one is not familiar with. Good luck with the build!
OP
tkappeler
Platinum Member
I do not know the science of smooth vs sheeps foot compaction but I have to go by the people doing the work.
Only a single 8" lift was necessary to get to the required height of the stone footing. Going higher simply allowed the excavator to dig out the trench to put the stone in. Although superior walls and the architect only required a minimum of 6" of 3/8" stone above the single 8" lift, we have a 10" stone base. The garage walls are only about 200# per linear foot and the loads on that will be pretty minimal ... walls, trusses, sheathing, shingles for the garage.
Here is a rough drawing of the garage buildup.
The excavator has been in business 30+ years and has the utmost reputation and experience.
sdkubota
Platinum Member
If it was just the stone footing the roller would be fine. I thought they bagan filling and compacting the surrounding grade. A smooth drum roller on rock is the right compaction equipment. I must had read things wrong...sorry. I love the idea of precast basement walls.
OP
tkappeler
Platinum Member
You did not misunderstand. They used a flat roller for a single 8" lift for the entire garage area. This is the level that the gravel would begin. They brought in a second lift and repeated with the roller. They then dug out the trench for the gravel to go in. The depth of the trench brought it down to the height of the first lift. This was filled with gravel and re-compacted.
Anything else above this will be done with a small roller (I will inquire about a sheep's foot roller) and jumping jack. Rebar will be attached to the brackets on the back wall (see photo below) and bent out. This gives more rebar embedded in the slab to keep it from sinking.
sdkubota
Platinum Member
Anything can achieve compaction given the proper useage, correct procedure, and optimum moisture levels. A wacker packer (jumping jack) or smooth drum rollar is good for a maximum of 4" loose lift height. Wheel compaction below a bobcat maybe 6" maximum loose lift. A large payloader or sheepsfoot roller with a loaded bucket maybe 12" lifts of loose fill height. A fully loaded scraper 2' loose lift height. Nothing will compact dirt in greater than 2' lifts (dynamic packing by dropping large weight a great distance is an exception).
955Lincoln
Gold Member
Very good information! If I'm not mistaken another couple of feet needs to be added to get at pad level. I would be watching closely and as sdkubota mentioned, moisture levels play an important part as well.
mjncad
Super Member
I think this is a good idea considering how much the OP has to raise the level of the garage slab. Better to spend a few bucks now and correct it if need be then blow it off and have the hideous expense of replacing a garage slab later.
Are you saying the garage slab will be tied to the foundation walls? Does your soil conditions permit that? Did the structural engineer say that is OK to do? The reason I ask is that if that were done here with our expansive (hot) soils; you would more than likely end up with major damage down the road. Yesterday my wife and I toured a neighbor's house built by the same clown who built our place. Their problems make ours look minor. Besides shoddy workmanship by the builder, our hot soils finished wrecking their house. From what I saw of it, at a bare minimum the finished basement has to be gutted and the concrete floor blown out and redone; but based on additional damage caused to the main floor and exterior by the heaving soils it would be better to scrape the house off and start over. Be careful tying slabs to the foundation is my only advice, especially since you have such a high water table.