"kellysheroes" wrote in message
m...
We're planning on having a 1000 ft2 flagstone patio installed. We
have received estimates for both a dry install with rock/stone(?) dust
and a mortored install. What are the pros and cons of each. We live
in Northern Virginia by Washington DC. We do have a large, mature
sugar maple that will be approximately 6 feet from one corner of the
patio. Our concerns are these roots and heave.

see:
http://www.biobarrier.com/

biobarrier is like a ribbon eother 12" or 20" or so wide

it comes in like 100 foot or larger rolls

you may be able to cut through the stability roots
(which usually can't grow any deeper than the 20" or so biobarrier ribbon
width)
on the side you fear,
right next to where the patio will be,
run the biobarrier in a trench,
seal it all back up,
then forget about it

you may also want to be cognizant of where any gutter downspouts are in
relation to the tree/patio, as water attracts roots, and you may be able to
reroute any such gutters or roof runoff etc. away from the patio and to an
area of the tree and yard that can best use the water


We want a very flat
surface which leads us to mortored, but are afraid of cracking in the
cement due to the roots.

biobarrier can stop this,
as i mention above

you will have to make the determination if it will apply to your situation
there is plenty of information available

We believe that we can repair any root
movement in a dry install, but worry about the overall flatness over a
period of time. Thoughts?