All of our brick and flagstone surfaces are supported by a thick, firm concrete base.  We do not recommend putting them on a sand base, as these tend to shift and heave over time.

We form and pour the area, then lay the brick or stone on a bed of mortar.   When that is dry, we then hand morter and finish the joints for a clean, smooth appearance.  This type of surface will stand up very well against the repeated freeze and thaw cycles of the Northern Virginia area.