Pools are designed to keep water in, of course — but with vinyl-liner vessels, a central need for builders and service techs is keeping water out. When the pool is built, care needs to be taken when backfilling it to ensure any exterior water will drain away from the pool.

Also, specific steps need to be taken prior to installing the liner to prevent water from seeping through the joints of the panels or through the top of the panel and coping. The easiest place for this water to flow is through the seams of the panel joints. When water gets between the liner and the pool wall, it can then bring particles of dirt and grit through the panel seams; the dirt then becomes trapped between the wall and the liner. In regions where there is seasonal freezing and thawing, the grit can create small pinholes in the vinyl. In the worst-case scenario, the liner can even begin to float.

Clean panel face

Builders should take great care to clean the panel face before they install the liner so it is free of grit or debris that could get caught behind the liner. It becomes very frustrating to return to a pool after it is filled and find grit behind the liner, even after doing a thorough job of cleaning the walls earlier. If you run your hand over the liner and the surface feels gritty, not smooth, you’ve likely had water seep behind the panels, pulling this grit between the liner and the wall.

The best way to prevent problems such as these is to ensure a watertight seal when the liner is installed. Many installers will simply apply duct tape along the seams of the liner panels after they’re installed. That’s not sufficient. The key is to ensure those seams are watertight before installing the panels.

Here’s how to do it. First, whether you’re installing a polymer or steel pool, you’ll want to caulk the wall panels prior to installing them. Use a tube of clear 100 percent silicone caulk, available at any hardware or home store. Put a generous bead of caulk down the side of the flange of the panels, in front of the bolt holes. Then bolt the panels together. Make sure you have good coverage. Use a spackling knife to ensure the caulk is flush on the panel face to avoid an uneven surface. Then you can run a piece of quality duct tape down the entire length of the seam to reinforce the seal and protect the liner.

Next, using the same caulking technique, you should seal the areas where the panel bolts to the flanges of the molded steps.

Don’t neglect panel top

Finally, we need to address the area where the top of the panel meets the coping. This area is a particular concern because water will bleed out of the concrete and under the coping after it is poured. This can pull bits of the concrete down behind the liner, causing the same problems described earlier. Again, many installers will simply apply duct tape to the front of the aluminum receptor. This is insufficient to completely prevent seepage.

Once more, use caulk prior to installing the receptor. Use a generous bead of silicone caulk on the front of the top lip of the panel, about 1 inch to 1-1/2 inches from the edge. Place the coping on top of the panel, then use tech screws to attach it to the top of the panel. At that point, the duct tape can be applied around the entire perimeter where the top of the receptor sits on the wall. Having this watertight seal around the entire perimeter will enable you to efficiently remove the air from behind the liner — creating a tight seal when the liner is put into place.

Sealing steps is key

Another area where the clear silicone can help (and add a little peace of mind) is around the faceplate of the steps. After securing the faceplate over the liner and cutting out the step opening, apply a bead of silicone around the inside of the faceplate where the cut liner edge and the faceplate meet. Use your finger and smooth out the silicone bead so it leaves an almost transparent seal around the perimeter of the faceplate.

This will add an additional level of security to ensure you have a leak-free seal around the step area.

These additional steps will add a bit of time to the installation procedure, but in this case the ounce of prevention is more than worth it. Water seepage behind the liner can lead to expensive liner repairs or replacement down the line — which will most certainly lead to an unhappy, unsatisfied customer.

Bill Wiley is a 42-year industry veteran. He joined Latham International in 1983, serving as director of marketing, sales, and customer/technical services, respectively. Currently, he is senior product director.