We re-lined our in ground pool about two years ago. At the same time we had the concrete decking surrounding the pool ripped out and redone. After a cold hard winter the decking surrounding the pool is now tilting inwards toward the pool. One part of the deck is edging up against the lawn and one part up against interlocking brick. I know we won't know for sure until the ground thaws, but is this a just a temporary shifting which will correct itself or do we need to worry? Any input is appreciated! Thanks.

I'm pouring a 12x8 floating shed slab and think I need to install drainage pipe around perimeter to protect it from heaving. My questions are do I need to install the drainage pipe and how to install it. Slab site is on my side yard at base of a hill, and the long side is about 30 degrees from perpendicular to the incline. Incline extends about 25' up from shed wall until it ends at neighbor's house. Total rise is around 3' over the whole 25' span. It's the water coming down this hill that worries me. Soil is very sandy and well drained. I lived in Maryland (plant zone 6a). Frost line is 3' down. Is the drainage pipe a good idea or overkill? Assuming I need the pipe: -how deep should pipe be? -how much gravel do I need under, beside, and on top of pipe? -any easy way to estimate gravel amount, such as X gravel per foot of pipe? I assume install procedure is to dig a shovel wide trench, set downhill incline, lay filter fabric, add gravel, lay pipe, more gravel, wrap fabric closed, and back fill with soil. If necessary, I could also extend pipe additional feet off downhill side of shed. Thanks in advance for your advice. Dave