Preparing a building pad

[yhuynh]

Hello All,


I'm building a house in NY and naturally the first step is to prep the building pad. It's my first time doing this so I'm feeling a bit nervous about the whole thing. I'm hoping kind, experienced folks can review my plan of action and give suggestions/insight. Much appreciated!


The building is a 32x56' pole barn with a 10' wide patio on the front of the building - 4' deep piers and 5" floating concrete slab - wire mesh and fiber mesh as spec-ed by engineer.

I dug a 24" deep test hole the other day...If I'm reading it right, the topsoil appears to be fairly shallow, about 4-6". It's not too obvious when looking at the layers, but the subsoil is quite a bit yellower.




So the plan is to:
1) Dig out 10-20 stumps under and around the building pad. These range from 12-36" diameter, thinking I'll rent a 30 ton machine for this.
-Is backfilling with subsoil or fill and compacting with excavator bucket enough? Or should I run a vibratory plate over these?

2) Scrape off the top 6" of a 52x66' area and put it in a pile for spreading later. Should be approx 73 CY with fluff
I'll do the same to connect the existing driveway to the new building as well.
- Not sure what the best machine is going to be for this - I can get a 75hp tracked skid steer or a 77hp Cat dozer locally. I've never run a dozer before so not sure how efficient I'll be with that. Would using the 30t stumping excavator for digging and skid steer for moving material be awkward/overkill? I feel pretty comfortable operating excavators but the biggest I've used is 12ton

3) Bring in fill and compact in 6" lifts. Back corner of building is high maybe 12".
-Do I have to bring the rest of the pad up to this grade, or can I make kind of a swale to push water either side? I'm in radon zone 1, so planning to install radon mitigation under slab. Engineer wants 6" gravel/crushed rock under the slab. Would it be worth doing 2" ROB and 4" clean gravel, or just use 4" clean for the whole thing? My wallet is hurting thinking about it.

4) Bring in crusher run to bring driveway up to grade



Thanks for reading!

 

[jack stand]

I think you mean a 30k pound or 15 ton class excavator. Yes that's what you want for the stumping job and excavating and stockpiling. Then you can move the material around and grade with the SS/ctl although the excavator is going to pile it up way faster than the SS is going to move it.

 

[Scotto]

A vibratory roller isn't going to help for this type of compacting. Might be OK for a patio or something but it doesn't provide the compaction needed for this. Look into renting a remote control trench sheepsfoot roller. I had a huge tree in the middle of where my garage was going and had a 3' hole there. Rented the roller, filled it in like 4-6" lifts, and compacted and continued.
Also, if it's going to be awhile, time helps with settling (if it's going to be a good amount of time).

 

[yhuynh]

Thanks for the response!

Yes you're right, I meant a 30,000 lbs machine!
That some serious roller, but you're right I do think a ride-on roller is going to be much more appropriate and also faster.