Tree Roots-Leave in ground or Excavate?

[Able Al]

How long does it take a tree root and stump to decay and cause sinking?

I'm having my driveway paved with asphalt and I have a few tree's (12"-18" in diameter) that are right on the line being cut down. The new asphalt will be going right to the edge of the tree's so they will be coming down.

My question is, would it be OK to leave the root ball underground after being cut and ground down, or will it cause sinking? Debating on grinding the stumps and leaving the root ball underground, or having them excavated.

Think the ground and driveway pavement will sink if I leave the root in the ground that will eventually decay? Or will it take a long while or will the ground stay sturdy enough?

Any feedback appreciated

 

[ATH]

If it is ground deep enough and wide enough, it should not be an issue.

However, that is deeper than "normal" so it will cost more. I'd have an excavator pop them out. That is a lot of money you are putting on top of it, and a lot of headache if it is not done right. I'd probably be a little afraid of hiring a paver who doesn't want them dug out...

 

[Able Al]

If it is ground deep enough and wide enough, it should not be an issue.

However, that is deeper than "normal" so it will cost more. I'd have an excavator pop them out. That is a lot of money you are putting on top of it, and a lot of headache if it is not done right. I'd probably be a little afraid of hiring a paver who doesn't want them dug out...

Thanks for the reply. I'm unsure what you mean by deep enough and wide enough. If I had to guess these roots probably grew straight down since there is asphalt on both sides and it wasn't buckled or lifting. The tree's sit right on the properly line where my asphalt and fence land. The tree's have grown their way over to my side over the years so we are removing them. The paver said it is my choice but that with time eventually the ground will sink where the decay occurs probably. Just unsure if digging out and putting soil will be all that much more sturdy as I've seen compacted soil sink after only a few years of settling. So is leaving a root under ground that will rot better, or pull the root and put in new soil which may settle anyhow. Financially its a lot more to get those roots out as well.

 

[ATH]

I mean if the stump grinder goes down to the bottom of the wood stump...into soil. Properly compacted soil will hold up.

 

[Able Al]

I mean if the stump grinder goes down to the bottom of the wood stump...into soil. Properly compacted soil will hold up.

Any idea how deep you'd have to grind for a 12"-18" diameter tree to hit that point?

 

[Babaganoosh]

I bought my house 2 years ago. The previous owners had trees cut and stumps ground 3 years before that. They probably weren't ground too far below grade because they are sinking. I've added a few inches of dirt about 3 times now. I've gotta add about 3 inches more in spots currently.

I second having an excavator rip them out. Once they are gone they are gone for good. If possible I'd let a year pass and get thru one frost cycle and let all the new fill and soil settle but I'm overly cautious sometimes.

 

[ArtB]

Added caution: always call 811 even for grinding stumps!

Was digging a utility trench for a HO and they asked if I could pull an 8" plumb tree stump for them while backhoe was onsite. HO had cut down plum as it was making a mess of a parked car. Previous owners had planted the plum.
Called 811 to do additional locate in area the stump.

The GAS LINE was routed 10 ft from other utilities, and the gas line went right under the stump! Pulling the stump would have pulled and possibly broken the gas line along with root ball- BIG liability!

I always call 811 for anything anywhere over 6" deep in a residential area.

 

[stltreedr]

Any idea how deep you'd have to grind for a 12"-18" diameter tree to hit that point?

It depends on what species of tree... On average, a small stump like that probably not more than 8-10 inches. Fill it back in with gravel and minus, after you dig out all the grindings, of course.

 

[sb47]

It would all depend on the species of tree. some trees have shallow roots and some have deep roots.
A pine tree has a huge tap rood the goes strait down, so I wouldn't worry about then as long as there ground about a foot down past ground level. However if its a Elm tree, your gonna have shallow roots all over the yard.
Even if you get a little sinking in that spot, ash fault is easy to patch over.

 

[BC WetCoast]

Only some species of pines have tap roots. Most do not. Most trees don't have tap roots, because at depth there isn't enough soil porosity for air movement to allow for root cell respiration. The pines that have tap roots usually grow in fairly arid regions with coarse soils. The tap root is necessary to get moisture.

The roots of most tree species are within 18" of the surface to allow for air exchange and root cell respiration. Look at what happens when you compact the soil in the root zone, or add a lift of soil on top of the root mass. You end up with root death and tree stress.