compacting dirt

[trm70c]

I would probably figure out where your top of foundation is relative to existing ground. If you have 8' stem walls on a 12" deep footing than only fills > 9' should be of concern. I'm not saying that I would just bomb the dirt in, just that a concrete slab distributes the weight over a larger area than a footing with less loading. In other words a lower bearing is required for the floor slab than the foundations. But I wouldn't hesitate to call a local engineer, they are cheap and their experience can prove invaluable. A proctor test is only $150.00, field techs 85-100 per hour and the engineer shouldn't be more than $150.00/hr. For what you're describing, you could get sound engineering advice and support throughout the project for probably less than $2,000.

On another note, remember, a proctor only tells the maximum unit weight attainable by a material type, not it's bearing capacity. I could get a proctor on topsoil, doesn't mean I would want to build my house on it.

Finally, if I were you I would just hire a reputable local contractor. Not that I don't think you can handle the project, but they have the time, experience and insurance required to do the job right. Also with the market the way it is, contractors around here are doing work for just fuel and wages. You probably can't rent the trucks, loader and compactor for what they are willing to run their own for.

Best of Luck, Sounds Like a Fun Project.

 

[dirtmonkey]

I would probably figure out where your top of foundation is relative to existing ground. If you have 8' stem walls on a 12" deep footing than only fills > 9' should be of concern. I'm not saying that I would just bomb the dirt in, just that a concrete slab distributes the weight over a larger area than a footing with less loading. In other words a lower bearing is required for the floor slab than the foundations. But I wouldn't hesitate to call a local engineer, they are cheap and their experience can prove invaluable. A proctor test is only $150.00, field techs 85-100 per hour and the engineer shouldn't be more than $150.00/hr. For what you're describing, you could get sound engineering advice and support throughout the project for probably less than $2,000.

On another note, remember, a proctor only tells the maximum unit weight attainable by a material type, not it's bearing capacity. I could get a proctor on topsoil, doesn't mean I would want to build my house on it.

Finally, if I were you I would just hire a reputable local contractor. Not that I don't think you can handle the project, but they have the time, experience and insurance required to do the job right. Also with the market the way it is, contractors around here are doing work for just fuel and wages. You probably can't rent the trucks, loader and compactor for what they are willing to run their own for.

Best of Luck, Sounds Like a Fun Project.

. Sounds like good advice. Watch and learn or... Learn the hard way.I don't mean that negatively , just experience is a good teacher. Good luck !

 

[dayexco]

I would probably figure out where your top of foundation is relative to existing ground. If you have 8' stem walls on a 12" deep footing than only fills > 9' should be of concern. I'm not saying that I would just bomb the dirt in, just that a concrete slab distributes the weight over a larger area than a footing with less loading. In other words a lower bearing is required for the floor slab than the foundations. But I wouldn't hesitate to call a local engineer, they are cheap and their experience can prove invaluable. A proctor test is only $150.00, field techs 85-100 per hour and the engineer shouldn't be more than $150.00/hr. For what you're describing, you could get sound engineering advice and support throughout the project for probably less than $2,000.

On another note, remember, a proctor only tells the maximum unit weight attainable by a material type, not it's bearing capacity. I could get a proctor on topsoil, doesn't mean I would want to build my house on it.

Finally, if I were you I would just hire a reputable local contractor. Not that I don't think you can handle the project, but they have the time, experience and insurance required to do the job right. Also with the market the way it is, contractors around here are doing work for just fuel and wages. You probably can't rent the trucks, loader and compactor for what they are willing to run their own for.

Best of Luck, Sounds Like a Fun Project.

listen up here...his experience speaks volumes

 

[orville]

I would probably figure out where your top of foundation is relative to existing ground. If you have 8' stem walls on a 12" deep footing than only fills > 9' should be of concern. I'm not saying that I would just bomb the dirt in, just that a concrete slab distributes the weight over a larger area than a footing with less loading. In other words a lower bearing is required for the floor slab than the foundations. But I wouldn't hesitate to call a local engineer, they are cheap and their experience can prove invaluable. A proctor test is only $150.00, field techs 85-100 per hour and the engineer shouldn't be more than $150.00/hr. For what you're describing, you could get sound engineering advice and support throughout the project for probably less than $2,000.

On another note, remember, a proctor only tells the maximum unit weight attainable by a material type, not it's bearing capacity. I could get a proctor on topsoil, doesn't mean I would want to build my house on it.

Finally, if I were you I would just hire a reputable local contractor. Not that I don't think you can handle the project, but they have the time, experience and insurance required to do the job right. Also with the market the way it is, contractors around here are doing work for just fuel and wages. You probably can't rent the trucks, loader and compactor for what they are willing to run their own for.

Best of Luck, Sounds Like a Fun Project.

I did not think it would be that complicated of a job. This is not a job that I would start right away but it sounds like maybe I should hire out that part.

 

[Panhandler Bob]

before fillin?

Maybe I missed it did strippin sod &topsoil before fillin get mentioned? Also keyin in each lift into exsistin? Good Luck with your project. Bob aka ZZ

 

[coorecat]

There's a lot of variables to consider, material that came out,material going in,is a structure going to be on it or is it just fill,compaction equipment your using,amount of time between trucks if material not on
site,is a soil guy there testing,moisture curve usually + or - 2 % in NC depending on the proctor.As a
personal rule of thumb I try not to go over 20" to 24" on first lift and between 14" and 18" a lift after
that depending on soil and final compaction.

 

[coorecat]

I didn't see Trm70c's last post but he's dead on with his explanation,kind of what I was trying to say but he made it a little
bit clearer than I did.

 

[orville]

Maybe I missed it did strippin sod &topsoil before fillin get mentioned? Also keyin in each lift into exsistin? Good Luck with your project. Bob aka ZZ

I do not like burying topsoil so I was planning on removing that if I do the project. I do have a question though. Keying in each lift into existing? This was brought up on another post so I should have said something then.
How do you key in the lifts?
I would guess if you were going to put in a 12 inch lift you would make a 12 inch vertical cut into the existing hillside, so each lift has a step to rest on. That was a guess, can you tell me the correct way?

 

[buckfever]

When we do any compaction job we always use a soils guy. Just remember when it comes to how much is enough the enginier is the boss. They say only 12" and criss cross your compaction you should. Nothings worse then a unhappy enginier. I've never used just a truck (always a compactor pluse a truck) but I guess it could work. Also keep a good eye on the weather. Nothings worse then starting a pad and getting a inch of rain the next day.

When we do a small house pad or small slope extention when we build a key bigger is better. 3 to 4 feet deep and 8 to 10 feet wide. You need the dirt anyway cut it out and throw it to the high side. Also keep an eye out for water. If it looks like your going to make water look at putting in a slope drain. Just some perf-pipe and a foot of gravel.

 

[51kw]

That is exactly how you key in a fill. When compacting second pass at a 45 degree angle to the first pass is best.

 

[orville]

When we do any compaction job we always use a soils guy. Just remember when it comes to how much is enough the enginier is the boss. They say only 12" and criss cross your compaction you should. Nothings worse then a unhappy enginier. I've never used just a truck (always a compactor pluse a truck) but I guess it could work. Also keep a good eye on the weather. Nothings worse then starting a pad and getting a inch of rain the next day.

When we do a small house pad or small slope extention when we build a key bigger is better. 3 to 4 feet deep and 8 to 10 feet wide. You need the dirt anyway cut it out and throw it to the high side. Also keep an eye out for water. If it looks like your going to make water look at putting in a slope drain. Just some perf-pipe and a foot of gravel.

After I made that post last night I got to thinking. I bet a key is like a key way in a shaft. But I did not realize it would need to be 8 feet or so wide and 3 feet deep. The angles of compaction, I always wondered about also. I have another area that I would like to fill in over time. A house will sit there eventually, does that area need as much attention as a site where a building will go on it as soon as the area is filled in. Years ago I saw a builder have a hole dug for a full basement, before the footing guys got there the hole was half full of water. The builder had the hole filled in without compaction and the following year dug a hole half as deep in the same spot for a different style house. The question is if the fill dirt sits long enough does it need the compaction. The hole that was filled in and re-dug a year later was done by a slip shod builder if that means anything.

 

[Panhandler Bob]

topsoil

I was not meanin for you to bury topsoil, kinda unspoken rule among professional dirt hands that's a big no-no. If you cann't use it on your land you can always sell it. I should've been more spacific in my post. Good Luck, Bob aka ZZ

 

[buckfever]

I guess if you left the fill there for a long time(ten to fifteen years) it would probable pack down on it's own but leaving it only for a year is nowhere near enought time. Add water into the equation and I can garentee the house was built on crap ground.

On a side note as you bring your fill up we cut into the virgin ground a few feet. This will add a bunch of small keys that will also help hold the slope.

 

[orville]

Thanks to all you guys that shared your knowledge and experience, I may or may not do this project but I did learn a lot. I have learned also from reading posts throughout this forum. I just wish my memory was better.