Inground steel frame pool - Vinyl liner ? about corners

[fisherman]

Hello - This is a great place for information. I just recently purchased a home outside of chicago with a steel frame inground pool measuring about 20 x 40 or 22,000 gallons. The pool is old, built in 1975 and does have some significant evidence of ground heaving as the sides of the pool are bent inward. I have been told by neighbors and the owner the pool has been this way for 20+ years and the pool was constructed very well.
The pool had a new liner installed this spring 2013, presumably to freshen up the pool to sell the home. The pool inspector explained the technician did a good job with the liner considering the condition of the walls. The corners of the pool are perfectly square and are do not show the bowing I describe above. My question is, the liner where it attaches to the coping at the top appears to be stretched around the corner - more rounded and loose feeling. Below the water line it is adhered to the walls forming a crisp 90 degree bend with the walls. Is there a reason for doing this ? The liner at all 4 corners and at the tops of the stairs is loose feeling.

Thanks !

 

[honeydolisthater]

Vinyl liners are sized to be slightly smaller than the actual size of the pool and are designed to stretch tightly into the shape of the pool with the added weight of the water. This is due to the human nature of their installation and variances of pool floors etc. This method reduces the chances of wrinkles from excess product from trying to be to exact. Pool Companies try to give the most accurate measurements of the pool, and the liner manufacturing company makes the allowances for the stretch of the liner. In your pools case being older it has 90 deg corners the weight and pressure of the water push the liner further into the corner the deeper it goes. and less at the top. Newer rectangle models normally use radius corners that smooth out corners and reduce this effect. this should be of no concern to you as long as the liner bead (trim) remains in the coping and does not pop out.

This can also be remedied next time you replace the liner by retro-fitting radius inserts into the corners.

Also if you have children or curious adults resist the temptation to poke at the bouncy tight corners. Too sharp of a push could result in a tear.

hope this helps