Your above-ground swimming pool liner is what makes the pool look nice and feel smooth under your feet; plus, it keeps the pool intact longer by protecting its structure. However, above-ground pool liners only last a few years -- 10 at the most -- due to sun and other exposure. When it comes to replacing your above-ground pool liner, choosing the pattern is the easy part. Determining the type of liner and its thickness are also pretty straightforward. The more difficult part is measuring your pool to make sure you get the right size liner.
If you still have the owner's manual for your pool or you know where you bought it, you're in luck. You don't have to bother climbing around your pool with a tape measure to figure out its dimensions; the measurements should be listed in your paperwork. But if you inherited the pool from previous owners or you didn't keep the paperwork, get out that tape measure and a notepad.
For round pools, your measurement is simple. Just get in the pool and measure from one side to the other along the bottom from where the wall and floor meet. Measure in at least two places to ensure you've got the right measurement. For an oval pool, measure from the center of the long end to the center of the other end, and then measure across the middle (the shorter distance). On a rectangular pool, you also measure from the middle of the long end to the middle of the other long end and across the middle; however, you also need to note whether the corners of a rectangular pool are 90-degree angles, 45-degree angles or rounded. Regardless of the shape of your pool, be sure to measure the pool height, too. With these numbers, a pool retailer can help you pick the right liner.