GardenBanter.co.uk - View Single Post - Cut Flagstone Patio. Mortored or dry install?

27-01-2003, 11:26 AM

(kellysheroes) wrote:

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.

How much frost heave is there? The roots will ba a problem.

We want a very flat
surface which leads us to mortored, but are afraid of cracking in the
cement due to the roots. We believe that we can repair any root
movement in a dry install, but worry about the overall flatness over a
period of time.

If the stones shift, which they may do, you just pry it up and
add or subtract sand under it. If the sand bed is properly
prepared (deep and well-compacted) there should be minimal
shifting.

One way to handle this would be a mortared install for most of
the way, then the part closest to the tree being set in sand.

Tsu

--
To doubt everything or to believe everything
are two equally convenient solutions; both
dispense with the necessity of reflection.
- Jules Henri Poincaré