doomhunk
Newly Registered
Posts: 2
Joined: Mon Jan 15, 2007 9:21 am

Laying a driveway without clearing trees

Hi all

I was wondering if anyone here could provide me with some advice with regards to putting down a driveway on woodland.

A friend of mine has some woodland through which he need to create an access road for cars. The land itself and the mature trees on it are valuable, so he doesn't want to clear any of the forested area. He has heard that when laying a road, the ground should be dug to a certain depth, and then layers of hardcore, sand etc put down. However, he has also heard that one should not dig under the actual canopy of a tree. Herein lies the problem, as the woodland is apparently quite dense and he would like to position the driveway between several quite closely spaced trees.

I'd be really grateful for any advice you might be able to give.

Many thanks

Mark

MaineDesigner
Green Thumb
Posts: 439
Joined: Thu Nov 09, 2006 4:17 pm
Location: Midcoast Maine, Zone 5b

The short version is that yes, digging within the drip line of trees, i.e. under the canopy, is not recommended but with some species you can get away with it. The less the intrusion the greater the chances for survival.
Whether or not you create a proper road bed soil compression alone from vehicle traffic can be fatal to trees. Usually this sort of project involves sacrificing at least a few tree to give the rest of the woods the best chance of survival.
With more information about your location, the soils, the trees involved and how much and what type of vehicle traffic you anticipate I probably could provide a more detailed response. Oaks, at least the species native to the north central and north eastern U.S. are acutely sensitive to root disturbance and soil compression.

Newt
Greener Thumb
Posts: 1868
Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Hi Mark,

Some great advice from MaineDesigner. I totally agree with everything said except that tree roots grow beyond the canopy and drip line. Do avail yourself of the info offered by MaineDesigner. In he meantime you can share these sites with your friend that show how to protect trees from construction damage.
https://www.treehelp.com/howto/howto-prevent-construction-damage.asp
https://www.treesaregood.com/treecare/avoiding_construction.aspx
https://www.extension.umn.edu/distribution/housingandclothing/DK6135.html
https://www.treesaregood.com/treecare/treatment_construction.aspx

Newt

doomhunk
Newly Registered
Posts: 2
Joined: Mon Jan 15, 2007 9:21 am

This is all brilliant - thank you so much.

I will pass the info on to my friend, but in the meantime, I'd like to run another idea by you, if I may. I was advised to 'think outside the box' ie, to lay the road on top to the ground. The suggestion was to put down heavy sleepers and to lay the aggregate on top of that.

What do you think of this idea?

Newt
Greener Thumb
Posts: 1868
Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Mark, I see some potential problems with the advice you were given. You don't say where this road will be, but there is potential for heave of the sleepers from frost, the sleepers could shift with the vibration of traffic if there is nothing to keep them stable and in bounds, with snow cover a vehicle could run off the raised road and how would you plow it, washout of aggregate from heavy rains, shifting of aggregage due to heavy traffic. Sometimes saving a few dollars can lead to greater expense. I say to build it properly the first time, especially if this isn't a temporary road.

Newt

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