frost heaved pavers
I had a paver patio installed this past spring which had recently started show slight heaving in one section.
Background:The pool is an IG vinyl steel walled pool that was built in the fall of 2010. I waited untill the following spring to have the pavers laid. The base material was 3/4" processed gravel approx 12" deep. Compacted in lifts and pavers were laid in a 1" bed of washed concrete sand. Pavers were then mechanically compacted into setting bed and polymeric sand was swept into joints. My backyard is flat with no retaining walls or such of any kind. The entire pool area was graded such that it sits slightly above the surrounding yard and of course the patio slopes gradually away from the pool.
The damage appears to be isolated to a single area about 2' x 2' and I estimate the heaving to be about and 1" - 1.5" at the peak. However the overall affected area is somewhat larger as the this rise tapers off to the undisturbed sections. Obviously there is water trapped beneath that has frozen and caused this, but my concerns are:
1.) How likely is it that the pavers will return to thier orignal position come spring and is this something that can commonly happen to even properly installed paver decks?
2.) It has been an extremely mild winter here in southern NewEngland and I'm afraid the situation might intesify when the normal cold/precipatition arrives.
3.) Could I be faced with the unenviable task of removing pavers to regrade or installing drainage?
I will post actual pics of the damage when time permits, but for now I have included a drawing of my property.
There is 1/2" crushed stone everywhere inside the fencing where there is not pavers. The yellow circle represents the problem area.