Clearing tree for a new slab

[Dr.HairyOlds]

Hello,

In the planning process for a new 30x40 garage, 2x6 and truss construction. I'll be starting a build thread separately but had a question about slabs and trees.

There is a large tree in the yard that I'll want to take down regardless. In my preferred layout, the tree is within the slab area. Am I good to cut the tree, grind the stump and proceed or are there further steps before they can put the slab down? Approximate location of the tree is shown as the blue circle in the layout below.

 

[RivennHewn]

I wouldn’t just grind it. Pull it all, and replace with compacted fill.

 

[jkeyser14]

The stump has to be removed completely or else it will deteriorate over time and cause a large void under your slab. The proper way to do this is cut the tree and have 6' left sticking up so heavy equipment can use it as leverage knock it over and carry off the root ball.

 

[jack stand]

If the stump is out in the "field" of the slab and there's not going to be a point load in this area, you might be better off leaving it.
Removal of the stump without carefully compacted backfill of what's going to be a big hole may be worse.
Stumps without much air or moisture will decay very, very slowly.
Removing it is the right thing to do for sure, but having a crew of guys that properly fill and compact in shallow lifts is questionable these days and you might have a smaller disturbance that's more stable leaving the stump.

 

[tinmanwpk]

Agree with all comments - the tree stump must be removed entirely before the slab work begins. No grinding, complete removal. I just did that in an area I will be using for a future slab

 

[NUTTSGT]

You're going to be moving dirt and compacting new subgrade. Get the tree out now, in it's entirety.

 

[wssix99]

+1

Organic material needs to come out along with all the loose dirt around it. Quality compacted fill needs to go back in the place of all that.

 

[Beemer]

Agree with all the comments that you don't want organic material below your building.
Will add that that goes for the topsoil too.

 

[GirlnAgarage]

I wouldn’t just grind it. Pull it all, and replace with compacted fill.

This.

 

[mike93lx]

It's going to be a pain in the ***, but rip it out. It may mean a bigger excavator than would otherwise be needed for the foundation, but it will be worth it

 

[CraigStu]

I agree. A previous house had a fenced yard and we usually walked the dog around the perimeter. There had been a couple of trees removed by the previous owner. I realized that as there were some spots that I had to keep filling in. What I finally realized was they had removed the ball but all the roots were still there. And they were rotting softer. Not a big deal because all we did was walk there but over 5 years I filled in 3 times. I can only imagine what that would be like under a slab. So pay particular attention to roots that will be under the foundation even if it is just a thickened edge.

 

[ddurrett896]

I wouldn’t just grind it. Pull it all, and replace with compacted fill.

This is the way

 

[Cairo94507]

Indeed. We are in the middle of clearing, burning and grading right now - in fact they have 2 burn large burn piles going as I type. They came in with a D-6 Cat and another tractor and knocked the trees over, about 40 of them, mostly oaks. Then they dug out the root balls and began grading. We are building a 1,200 sq. ft. ADU with a 400 sq. ft. equipment/utility room and then a 2K sq. ft. garage, 40'x50'x14', for my twin brother on our property.

 

[plout99]

I agree complete removal is the best method, I will also add I took down a old chicken barn last year on my parents farm that had a stump covered by the slab and it had rotted a little not enough to cause any real voids and the stump had been covered with gravel and concrete by my grandfather in 1958 when the chicken barn was built. I think it’s going to depend on drainage around the building tree species and other factors to how fast it rots.

 

[Mytoolsupply]

How much topsoil do you have in your area? I've had trees like that in the past in the middle of slabs and by the time you grind it then strip all the topsoil there really isn't enough left to be a concern. Plus I'm sure your going to need to bring in stone to make your pad that will give you a solid enough base as long as you compact it properly.

 

[My Old Tools]

I had 5 huge oaks taken out where my shop is located. They dug them out with a big *** track hoe, then back filled in lifts. No cracks after 7 years.

 

[Kaizen]

I wouldn’t just grind it. Pull it all, and replace with compacted fill.

This. Leave 4 feet stump for leverage and have the excavator pull it out. those roots will rot over time so pull out what you can.

 

[Nosferatu]

Build around it.

 

[mike93lx]

Build around it.

You thinking treehouse or courtyard?

 

[Jim greengo]

I'd cut it off about 6' above ground,then dig around it wit a back hoe to loosen it up.
Then I'd use the back hoe to pop it out of the ground.

 

[mrbill55]

Hello,

In the planning process for a new 30x40 garage, 2x6 and truss construction. I'll be starting a build thread separately but had a question about slabs and trees.

There is a large tree in the yard that I'll want to take down regardless. In my preferred layout, the tree is within the slab area. Am I good to cut the tree, grind the stump and proceed or are there further steps before they can put the slab down? Approximate location of the tree is shown as the blue circle in the layout below.

As stated above, the tree needs to come out, and the stump dug out, not ground down, or you will eventually have a void under the new slab that could cause trouble a few years down the road. Since you are going to have a backhoe or some type of heavy equipment in the yard to do the site prep, digging out the stump should be a breeze for them.


Bill S.