How to Insulate an Above-Ground Pool

People usually use swimming pools during warm weather, so you may not think insulation would be needed for an above-ground pool to keep the water at a bearable temperature. But although an above-ground pool is warmed by the sun's rays during daylight hours, heat can escape at night when the temperature drops. Even if the heat loss is slight, it may make the water temperature unpleasantly cool by morning.

People jumping into a swimming pool.
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When an above-ground pool is insulated, the water will be comfortably warm for more of the day, and for more of the swimming season

The easiest way to keep your pool at a consistent temperature is by simply adding insulation to its outside walls. Pool insulation is sold in large rolls of foam material that resembles packing material or bubble-wrap. The air pockets in the bubbles create a barrier between the wall of the pool and the outside air, thereby preventing heat transfer from the pool to the outside air. Insulating your pool can make morning swimming much more pleasant, and it can also extend the swimming season in colder climates by a few weeks.

Quite a lot of heat escape from the surface of the pool, so to get the maximum benefit, it's important to also buy an insulated surface blanket to cover the top of the above-ground pool at night.

Step 1 Measure the Pool and Purchase Supplies

A roll of swimming pool insulation.
credit: Pool Supplies Co.
Insulation for a pool comes in rolls of foam-like material.

Measure the outside walls of your pool from top to bottom, and measure the circumference of the pool. Use these measurements to purchase an adequate amount of insulation from a pool accessories store. Describe your pool to the store clerk; he will have insulation specifically designed for above-ground pools. Buy clips that will fit the frame on your pool. Also, purchase a pool surface blanket to fit your pool. You can find these blankets in several different sizes. Purchase one that fits over the whole surface of your pool.

If you are buying your supplies online, carefully check sizes before ordering. And make sure the insulation roll is intended for use around the outer walls of your pool. Some products are designed to insulate the space between an inner vinyl liner and metal walls of a frame pool.

Step 2 Apply the Pool Insulation

Roll insulation can usually be applied in one large piece all around the outside circumference of the pool, but if it makes handling easier, you can cut it into smaller lengths using a utility knife. Try to arrange the insulation so the seams fall over the frame members, where they can be clipped securely.

Use clips specifically designed to secure the insulation to the frame members on the pool. These clips vary in size and are slipped over the frame to "pinch" the insulation in place. Take your time during this process to make sure the insulation fits tightly against the pool walls.

Step 3 Use a Surface Blanket

Closeup of insulated pool cover
credit: Poolsupplies.com
An insulated pool cover can reduce heat loss at night.

Place your water surface blanket on top of the water during the evening hours or at any point when the temperature starts to drop. The blanket will help keep heat from escaping when the pool isn't in use. Most surface blankets also have clips to secure the blanket around the edges.