UK gardening - Depth of tree roots

Author

Depth of tree roots

James

2006-03-28, 2:21 pm

Hi

I have a mature tree at the bottom of my new garden. I think it's a sycamore
(will have a better idea when the leaves grow) and it is easily over 40 feet
high.

I plan to build a garage/workshop on the land under the tree and this is to
include a service well, ie a sunken walkway in the floor of the garage, so I
can walk under a parked car to service it, rather than have to elevate the
car on ramps etc.

The pit will be about 6 feet deep and 3 feet wide and I wonder if digging it
will affect the tree.

I'm looking for information on the size, depth and spread of tree roots, so
I can gauge the likely impact of digging the foundations of the workshop and
the service well.

Can anyone point me to a site with this info, or do you know how deep a
sycamore sinks it's roots, and how far from the trunk they extend?

Regards
James

michael adams

2006-03-28, 2:21 pm

"James" <private@replyToGroup.com> wrote in message
news:4ueWf.10561$KF3.1202@newsfe6-win.ntli.net...
> Hi
>
> I have a mature tree at the bottom of my new garden. I think it's a
sycamore
> (will have a better idea when the leaves grow) and it is easily over 40
feet
> high.
>
> I plan to build a garage/workshop on the land under the tree and this is
to
> include a service well, ie a sunken walkway in the floor of the garage, so
I
> can walk under a parked car to service it, rather than have to elevate the
> car on ramps etc.
>
> The pit will be about 6 feet deep and 3 feet wide and I wonder if digging
it
> will affect the tree.
>
> I'm looking for information on the size, depth and spread of tree roots,
so
> I can gauge the likely impact of digging the foundations of the workshop
and
> the service well.
>
> Can anyone point me to a site with this info, or do you know how deep a
> sycamore sinks it's roots, and how far from the trunk they extend?
>
> Regards
> James

The recieved\anecdotal wisdom, is that a tree's roots, regardless
of species, can reach as far outwards as the spread of the
branches.

The degree to which any of these horizontal roots serve to anchor
the tree, will need to taken into account. The size of the actual
boughs on the tree, the amount of leverage they are likely to
impart on the trunk of the tree in high winds etc may
be related to the spread of the roots. And so it might be
unwise to disturb that balance.

The thing you need to bear in mind is that by severing any roots
on your side of the boundary you will be increasing the, theoretical
anyway, likelihood of the tree toppling into an adjacent property
and thus causing damage. More especially if the tree is heavily
laden with boughs on that side

Before going ahead, stand under the tree on a windy day and try
and estimate the likely effect might be, of severing any anchoring
roots.

michael adams

....

>
>
>

michael adams

2006-03-28, 2:21 pm

"James" <private@replyToGroup.com> wrote in message
news:4ueWf.10561$KF3.1202@newsfe6-win.ntli.net...
> Hi
>
> I have a mature tree at the bottom of my new garden. I think it's a
sycamore
> (will have a better idea when the leaves grow) and it is easily over 40
feet
> high.
>
> I plan to build a garage/workshop on the land under the tree and this is
to
> include a service well, ie a sunken walkway in the floor of the garage, so
I
> can walk under a parked car to service it, rather than have to elevate the
> car on ramps etc.
>
> The pit will be about 6 feet deep and 3 feet wide and I wonder if digging
it
> will affect the tree.
>
> I'm looking for information on the size, depth and spread of tree roots,
so
> I can gauge the likely impact of digging the foundations of the workshop
and
> the service well.
>
> Can anyone point me to a site with this info, or do you know how deep a
> sycamore sinks it's roots, and how far from the trunk they extend?
>
> Regards
> James

The recieved\anecdotal wisdom, is that a tree's roots, regardless
of species, can reach as far outwards as the spread of the
branches.

Correction:
<quote>
Roots on a mature tree may have a spread of at least twice the
height of the tree.
http://www.denvergov.org/Forestry/template23628.asp
</quote>

The degree to which any of these horizontal roots serve to anchor
the tree, will need to taken into account. The size of the actual
boughs on the tree, the amount of leverage they are likely to
impart on the trunk of the tree in high winds etc may
be related to the spread of the roots. And so it might be
unwise to disturb that balance.

The thing you need to bear in mind is that by severing any roots
on your side of the boundary you will be increasing the, theoretical
anyway, likelihood of the tree toppling into an adjacent property
and thus causing damage. More especially if the tree is heavily
laden with boughs on that side

Before going ahead, stand under the tree on a windy day and try
and estimate the likely effect might be, of severing any anchoring
roots.

michael adams

....

>
>
>

Nick Maclaren

2006-03-28, 3:21 pm

In article <48tcdbFljifhU1@individual.net>,
michael adams <mjadams26@onetel.net.uk> wrote:
>"James" <private@replyToGroup.com> wrote in message
>news:4ueWf.10561$KF3.1202@newsfe6-win.ntli.net...
>
>The degree to which any of these horizontal roots serve to anchor
>the tree, will need to taken into account. The size of the actual
>boughs on the tree, the amount of leverage they are likely to
>impart on the trunk of the tree in high winds etc may
>be related to the spread of the roots. And so it might be
>unwise to disturb that balance.

That is the main problem, yes. If it is a sycamore, it is unlikely
to be harmed by a bit of root pruning :-)

Regards,
Nick Maclaren.

Sheldon Harper

2006-03-28, 5:21 pm

"James" <private@replyToGroup.com> wrote in
news:4ueWf.10561$KF3.1202@newsfe6-win.ntli.net:

> Hi

> I have a mature tree at the bottom of my new garden. I think it's a
> sycamore (will have a better idea when the leaves grow) and it is easily
> over 40 feet high.

> I plan to build a garage/workshop on the land under the tree and this is
> to include a service well, ie a sunken walkway in the floor of the
> garage, so I can walk under a parked car to service it, rather than have
> to elevate the car on ramps etc.

> The pit will be about 6 feet deep and 3 feet wide and I wonder if
> digging it will affect the tree.

I hasten to point out that not only is the construction of such
a pit very expensive (you can buy an automobile lift for less)
but they're dangerous in several ways.

google "car lift" uk 62,600 hits

The only service pit installations of which I'm aware in the
US over the past half century are in quick oil change shops
and some large trucking company depots where pulling a tractor
and semitrailer over a pit is sometimes advantageous.

Make certain your insurance remains in force if you build one
of these anyway.

> I'm looking for information on the size, depth and spread of tree roots,
> so I can gauge the likely impact of digging the foundations of the
> workshop and the service well.

> Can anyone point me to a site with this info, or do you know how deep a
> sycamore sinks it's roots, and how far from the trunk they extend?

stumpy66

2006-03-29, 4:21 am

If you are building a garage under the tree, its not just that you will
cutting into the tree for your pit, but presumably for the foundations
for the garage as well. cutting any root will create an instablity of
the tree and open a wound for infection. also compression of the ground
will affect the tree. reducing air pockets in the ground and starving
it.....sycamore are not the most valued of trees. if you are going to
keep the tree perhaps you could reduce the size of the tree before you
build. this would reduce the risk of instability.

--
stumpy66

michael adams

2006-03-29, 5:21 am

"Nick Maclaren" <nmm1@cus.cam.ac.uk> wrote in message
news:e0c1b9$grt$1@gemini.csx.cam.ac.uk...
> In article <48tcdbFljifhU1@individual.net>,
> michael adams <mjadams26@onetel.net.uk> wrote:
>
> That is the main problem, yes. If it is a sycamore, it is unlikely
> to be harmed by a bit of root pruning :-)
>
>
> Regards,
> Nick Maclaren.

All the references seems to agree that sycamore is a shallow rooting
tree. So presumably any roots severed to a depth of 6ft will be making
a real contribution to the stability of the tree.

With mature trees in species amenable to root pruning such as sycamore
the recommendation seems to be to prune no more than one quadrant in any
one year, to be followed by a two year gap. This being presumably for
the health of the tree rather than stability as such. But presumably
the same would apply.

The "wind test" of standing under the tree should perhaps be carried
out in summer with the tree in full leaf, as this would present
more wind resistance and act more as a sail. This would all depend
of course on the direction of any prevailing winds in the OP's
locality.

The concerns raised about digging pits, when fully researched, might
seem to put the Kybosh on all this in any case.

michael adams

....

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