Preparing site for new house on slab

[rharkins]

We're just getting started planning a home on our land in central Missouri. It's native woodland with primarily oak trees. The soil ranges from sand and gravel to some kind of clay that hardens into black concrete once it's been disturbed and wet.

We need to remove about 50 trees ranging from a couple of inches to around 3 feet in diameter.

We'll be hauling in fill to level the site, but one corner will be right at the existing grade.

My question is do we bring in heavy equipment and dig up the stumps and roots, or do I hire the guy with a BIG stump grinder to grind the stumps off 6"-8" below grade?

We dug up some stumps for the road into the site, and despite filling and packing, most of the holes settled leaving significant divots. Keep in mind that we had to go 3'-4' deep to get them out.

On the other hand, if the tops are ground off, will the remaining stumps rot in the ground and eventually collapse leaving depressions?

Any opinions or advise?

Rick
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NH Boomer T3040

 

[dmccarty]

Have someone with a tracked excavator come in and knocked the trees over. It pulls up the root ball and if the excavator has a thumb they can hold up the tree while someone with a chain saw cuts the tree into logs. They can then clean up the site with a bull dozer.

This is what we did at our house site and it did not take them long to clear out an acre or two.

Hopefully there is a nearby sawmill that will buy the logs to help offset the price of the land clearing. But this is very location specific.

My neighbor made the mistake of having a tree service cut down an acre or two of hardwoods. Then he tried to have a stump grinder clean up the mess. It was a mess for a year or two until he hired a company with an excavator to dig up the stumps and a dozer to level everything. If he had just done this to remove the trees he would have saved a bunch of money and time.

The mistake we made when clearing for our house was not taking down enough trees. There are some that if they fall I am a afraid they might hit the house. They are big oaks, maybe 24-32 inches in diameter and with todays timber prices they might be worth $100-200 a tree which is nothing compared to the cost of the tree falling on the house.

Later,
Dan

 

[Kays Supply]

If you plan to build where the stumps are, keep in mind termites will be attracted to any decaying wood left behind. Also , I am a plumber by trade. You need drainage away from your slab. Water can build up under a slab and cause more problems than you can imagine. One single pipe from the low end out to grade will handle it fine. I have heard of homes with so much water under the slab that the hot water was cooled before it could get from the water heater to the farthest faucet.

 

[dave1949]

Foundations or slabs are never put on top of any organic material. You need to excavate at least to 2-4" below any sign of roots, etc in the soil. It all has to go!

In reality, if you want the finished slab to be at or near existing grade level on one corner as you mentioned, then you need to excavate down the thickness of the slab plus the thickness of under-slab insulation plus the thickness/depth of the stone drainage bed mentioned in the previous post.

I don't want to be a wet blanket, but the fact you asked this question tells me you would be better off hiring a good foundation contractor for this part of your building project. Foundation and slab problems are very difficult and very expensive to fix, especially with a house sitting on them. You could end living with a dampness/wet problem or worse. It's not like a wood frame wall you can tear down and redo if it is built wrong.

It's great to educate yourself on the issues, but you can't hope to know or learn in a short time what someone knows who does this for a living.

Dave

 

[Highbeam]

Have the stumps removed and properly backfilled and they won't settle. Your road building shows what happens when the stump hole isn't properly backfilled. The last thing you want is a buried stump anywhere near your home or road.

It's easy peazy to pop the stumps out with the proper excavator.

 

[rharkins]

I don't want to be a wet blanket, but the fact you asked this question tells me you would be better off hiring a good foundation contractor for this part of your building project.

I appreciate the advice. I'll certainly get someone experienced to take care of the footings and slab work. This is going to be a multi-year project, and we probably won't start on the building for at least a year. I wanted to get the site prepared so it could settle for a year before we started.

The guy with the grinder had a good story, but I was suspicious. That's why I came here!

Rick

 

[rharkins]

Here's a picture of the road...

 

[EddieWalker]

Think of all the money, time and effort that will go into building this house, and then decide if cutting corners on the soil that it will be sitting is really saving you anything if the foundation cracks, water gets into the house when it rains and the walls beging to shift. The best way to save money long term on building a house is to spend the money on your soil work and foundation work. You can save on other things, but never try to save a buck in these areas.

As already mentioned, you don't want anything under your foundation that will rot on you. You have to make sure that all dug up soil it replaced with qulaity, clean soil that is highly compacted.

Find out what type of clay you have. Just calling it black clay means nothing. Some clay materials are excellent for building on, others are absolutley terrible. Know what you have and be sure of your source. Unfortuanatey, allot of equipment operators pretend to know their soils, but most don't have a clue what the ratings are for those soils and which ones to avoid when building a house.

When you mention that one corner is at existing grade, what is the drainage like for that corner? Since you are working the soild, take the time and effort to get your slopes right and ensure that the water will always run away from your home. Never rely or expect to use french drains or pipes. Slope the soil. Pipes plug up, drains fail. Slopes always get the job done!!!!!!

Eddie

 

[dave1949]

I appreciate the advice. I'll certainly get someone experienced to take care of the footings and slab work. This is going to be a multi-year project, and we probably won't start on the building for at least a year. I wanted to get the site prepared so it could settle for a year before we started.

The guy with the grinder had a good story, but I was suspicious. That's why I came here!

Rick

I'm glad to hear that. I imagined a situation where you might be moving along a lot faster. I really do respect people who roll up their sleeves, ask questions and dive in. I just hate to see a possible bad/expensive result with the best of intentions.

Eddie makes some excellent points too. Best thing is to find a contractor who has excellent references in your area and take the time to talk to those references to find out if their project was similar to yours.

Dave.

 

[Uncle Doug]

I don't want to be a wet blanket, but the fact you asked this question tells me you would be better off hiring a good foundation contractor for this part of your building project. Foundation and slab problems are very difficult and very expensive to fix, especially with a house sitting on them.
Dave

I also second this idea. A co-worker had a very nice county home built just down the road from me about 5 years ago. Used a local but very small builder. No special peperation of ground work other than built it up a little. This was pasture land, no trees or stumps. Now 5 years later they have major slab issues and no slab warranty.