What Causes Pinholes in Above Ground Pools?

Rocks and Sticks Under the Pool

• An above-ground pool rests in an excavated depression in the ground called a cove. All sod, plants and rock must be removed from the cove, and the surface must be prepared carefully to eliminate anything rough or sharp. The weight of the water will press the liner against the ground, and even tiny particles rubbing against the liner can cause a pinhole in the liner material. The pool should be installed on a carefully smoothed 2-to-3-inch base of clean washed masonry sand inside the entire pool cove.

Damage While Cleaning

• Old or worn cleaning equipment is another source of pinholes. Check the surface of each item that goes into the pool to be sure that there are no chips or crack in the plastic or metal. Hand-held vacuum heads often cause wear in the liner, making it more vulnerable to small punctures, especially along the sides. According to the Shade Builder website, you should "vacuum the bottom of the pool only, do not get within 6 inches of the sidewall. The vacuum head against the sidewall of the pool will cause pinholes just about every time.” Automatic cleaners are useful for pool maintenance.

Pool Toys

• Items with sharp edges should not be brought into the pool, and this includes metal or hard plastic toys. These toys often sink to the bottom of the pool where swimmers can step on them, resulting in punctures in the pool and injury to swimmers’ feet. No glass should ever enter the pool area, both for safety and to protect the pool liner. Foam pool toys often pick up small rocks and sticks that can cause pinholes. Swimmers also regularly bring little rocks into the pool on their feet.

Deterioration from Drying

• If the pool is drained and not refilled immediately, the liner will dry out, causing deterioration that will leave it vulnerable to small cracks and holes. The pool also will lose water during the swimming season, too, due to splashing, evaporation or filter leaks. The evaporation rate depends upon temperature, wind velocity and humidity. Ted Hebert, the owner of Teddy Bear Pools, warns on the company’s website that “people can lose up to one inch overnight” due to evaporation. That can leave the sides of the pool exposed and accelerate drying of the liner. Overusing chlorine can also weaken the liner material.