How to Fix a Leaking Pool Skimmer

Frequently Asked Questions

How do I know if my pool is leaking from the skimmer or just evaporating?

The bucket test distinguishes evaporation from a structural leak. Place a bucket of pool water on a step, mark both water levels, and leave for 24-48 hours with the pump off. If the pool drops significantly more than the bucket (which also evaporates), you have a leak. A pool losing more than 1/4 inch per day beyond what the bucket shows warrants investigation. Most pools lose 1/8 to 1/4 inch per day to evaporation alone in warm weather.

Can I use regular waterproof epoxy to repair a pool skimmer crack?

Use pool-specific putty or epoxy, not generic hardware store epoxy. Pool repair putty (such as Pool Putty or Harvey's Pool Putty) is formulated to cure underwater and resist chlorine and pool chemicals over the long term. It can be applied even with water present, which makes it practical for skimmer body repairs. Standard epoxy will eventually degrade from chemical exposure and chlorine.

How much does pool skimmer repair cost?

DIY faceplate gasket replacement: $10-$25 in materials. DIY skimmer body crack repair with pool putty: $15-$40. Hiring a pool company for skimmer repair: $150-$400 depending on the repair type. Full skimmer replacement (required for severely cracked or deteriorated units): $400-$1,200 including labor, or up to $2,000 for concrete pools where the deck must be cut.

When do I need to replace the entire pool skimmer instead of repairing it?

Replace the skimmer when: the body has multiple large cracks or a structural crack through the throat where it meets the pool shell, the plastic has become brittle and crumbles when prodded, or repeated putty repairs keep re-cracking within a season. For concrete pools, skimmer replacement requires cutting the deck and is a significant job; for vinyl liner pools, it is more manageable but still requires draining and liner work.

Diagnosing and fixing a leaking pool skimmer: (1) Confirm the leak is from the skimmer (not evaporation) — mark the waterline, turn off the pump for 24 hours; if water drops 1/4 inch or more, you have a structural leak. (2) Faceplate leak (most common) — remove the faceplate screws, replace the foam gasket, reinstall with stainless screws.

A leaking pool skimmer can drain thousands of gallons of water over a season and send your water bill through the roof. Whether the leak is coming from the faceplate gasket, a crack in the skimmer body, or a failing plumbing joint, most skimmer leaks are surprisingly fixable without calling a pool company. This guide walks you through diagnosing the source of the leak and making a lasting repair.

Understanding How Pool Skimmers Work

The skimmer is the rectangular box built into the pool wall near the waterline. It draws surface water in through a floating weir door, traps debris in a basket, and sends filtered water back to the pump. There are four main places where a skimmer can leak:

1. The faceplate gasket — the rubber seal between the decorative faceplate and the pool wall
2. The skimmer body — cracks in the plastic housing from UV damage or ground movement
3. The plumbing fittings — unions or glued PVC joints where water exits toward the pump
4. The skimmer throat — where the skimmer box meets the concrete or gunite pool shell

Pinpointing the leak before buying materials saves time and money. The dye test is your best diagnostic tool: squeeze a few drops of food coloring near suspected areas with the pump off. If the dye is pulled toward a crack or gap, you’ve found your leak.

What You Need

Before starting any repair, gather your materials. Having everything on hand prevents mid-job trips to the hardware store.

• Pool Putty (Two-Part Epoxy Putty) — for underwater crack repairs
• Pool Skimmer Gasket Kit — universal fit or brand-specific faceplate seals
• PVC Pipe Cement and Primer — for resealing plumbing joints
• Plumber’s Putty — for faceplate joint sealing on non-pressure surfaces
• Waterproof Silicone Sealant — for non-submerged gaps and cracks
• Pool Dye Test Kit — leak detection tablets or liquid

Diagnosing the Leak

Before touching any materials, run through this diagnostic sequence:

Step 1: Watch the water level. Mark the waterline with tape and check it after 24 hours with the pump running, then again with the pump off. If the pool loses water only when the pump runs, the leak is likely in the plumbing or on the pressure side. If it drops equally either way, the skimmer body or faceplate is the more likely culprit.

Step 2: Check the faceplate. Look for gaps between the faceplate and the pool wall. Older pools often have crumbling or missing putty in this joint. Run your finger around the perimeter — if you feel soft, deteriorated material, the seal has failed.

Step 3: Inspect the skimmer body. Reach down into the skimmer and feel along the walls and floor for cracks. Look for staining patterns that show where water has been escaping. Hairline cracks can be hard to see but easy to feel.

Step 4: Check plumbing connections. With the pump off, inspect the fittings at the bottom of the skimmer where the pipe exits. Look for white calcium buildup or water staining around joints, which indicates a slow seep.

Repairing the Faceplate Gasket

This is the most common skimmer leak and usually the easiest to fix. The faceplate (also called the skimmer cover or trim ring) is held to the pool wall by a series of screws. Over time, the gasket or putty behind it dries out and fails.

Drain the pool slightly below the skimmer opening — you don’t need to drain it completely, just enough to work on the faceplate without fighting the water.

Remove the faceplate screws. These are usually stainless steel Phillips-head screws. If they’re corroded, apply penetrating oil and let it sit for 10 minutes before removing.

Peel away old putty or gasket material. Use a plastic scraper to remove all remnants of the old seal. Clean the surfaces with acetone or rubbing alcohol and let them dry completely.

Apply new gasket or putty. If your skimmer came with a replacement gasket kit, seat the gasket around the faceplate perimeter before screwing it back in. If you’re using plumber’s putty or pool putty, roll it into a rope and press it into the groove around the opening. Do not use regular silicone here — it won’t adhere well to the pool surface and will fail quickly.

Reinstall the faceplate. Tighten screws gradually in a cross pattern to compress the gasket evenly. Wipe away any putty squeeze-out before it sets.

Repairing Cracks in the Skimmer Body

Cracks in the skimmer body require an underwater epoxy repair because you often cannot drain the pool enough to work in dry conditions.

Pool putty is a two-part epoxy that cures underwater. Knead equal parts of the two components together for 2–3 minutes until the color is uniform, then press it firmly into the crack. Smooth it with a wet finger. It typically takes 30–60 minutes to set and 24 hours to fully cure. This works best for cracks up to about 1/4 inch wide.

For larger cracks or structural damage, a hydraulic epoxy designed for concrete and fiberglass pools is a better choice. These products bond to wet surfaces and expand slightly as they cure, which helps fill irregular voids.

If the skimmer body is severely cracked or the skimmer housing has separated from the pool shell, that job requires professional intervention. A pool company will need to cut away the damaged skimmer, install a replacement, and replaster or patch the surrounding shell.

Sealing Plumbing Joints

Leaks at PVC fittings are tricky because they often require cutting into the line and re-gluing or replacing the fitting entirely.

First, confirm the leak location using the dye test method. Drip dye around the fitting perimeter with the pump running very slowly. Watch for movement in the dye — if it gets pulled into a gap, that’s your leak.

If the fitting is accessible and above the waterline, dry the area thoroughly and apply PVC solvent cement around the joint. On an existing joint, this is a temporary patch at best — solvent cement is designed for fresh cuts. A more reliable repair is to cut the pipe, install a coupling, and glue in a new section.

For unions, simply unscrew the union, replace the O-ring or washer inside, apply fresh thread sealant tape, and reassemble. Tighten firmly but don’t overtorque plastic fittings.

Putty vs. Epoxy: Choosing the Right Product

This is the most common source of confusion for pool owners doing DIY skimmer repairs.

Plumber’s putty is a soft, oil-based compound that stays pliable indefinitely. It’s good for faceplate joints that don’t need a rigid bond, but it can dry out over years and should not be used for crack repairs.

Pool putty (two-part epoxy) cures hard and is designed for underwater use. It bonds to plastic, fiberglass, and concrete. Use this for skimmer body cracks, concrete shell gaps, and underwater repairs.

PVC cement is the right product for plastic plumbing joints. It chemically welds PVC and is the only appropriate choice for re-joining or patching PVC pipe and fittings.

Silicone sealant is fine for above-waterline gaps, around the skimmer lid, or where the skimmer deck ring meets the pool coping — but it doesn’t bond reliably to surfaces that are wet or submerged.

Refilling and Testing

After completing the repair, wait for the full cure time before refilling. Pool putty needs at least 24 hours. PVC cement needs 2 hours minimum before pressure is applied, but 24 hours for full cure.

Refill to the normal operating level, run the pump, and monitor the area for 24–48 hours. Repeat the dye test around the repaired area if you want visual confirmation.

If the pool continues to lose water at the same rate after the repair, the leak may have a second source. Run a full bucket test (place a bucket of water on the pool step and mark both inside and outside water levels) to determine whether the loss is from evaporation or an active leak.

Frequently Asked Questions

• question: “How do I know if my pool skimmer is leaking or if the water loss is just evaporation?” answer: “Do the bucket test: fill a bucket with pool water, set it on a step, and mark both water levels. Check after 24 hours. If the pool loses more water than the bucket, you have a leak. Pools typically lose 1/4 to 1/2 inch per day to evaporation in hot weather.”

• question: “Can I fix a skimmer leak without draining the pool?” answer: “Yes — pool putty and hydraulic epoxy are specifically designed to cure underwater. You can make most skimmer body crack repairs without draining the pool. Faceplate gasket repairs do require draining the water level slightly below the skimmer opening.”

• question: “How long does pool putty last?” answer: “A properly applied pool putty repair can last 5–10 years. Factors that shorten its lifespan include major ground movement, freeze-thaw cycles, and pool chemistry that is consistently out of range (very high or very low pH degrades epoxy faster).”

• question: “What causes pool skimmer cracks?” answer: “UV exposure degrades plastic skimmer bodies over 10–15 years. Ground movement and settling put stress on the skimmer body. In cold climates, water left in the skimmer during winter expands when it freezes and can crack the housing. This is why winterizing includes adding a skimmer plug.”

• question: “Is skimmer putty the same as pool putty?” answer: “They’re typically the same product — a two-part underwater epoxy. Brand names vary but the chemistry is similar. Avoid general-purpose epoxy putty from hardware stores, which may not be rated for continuous water submersion or pool chemical exposure.”

• question: “Should I use silicone or putty around the skimmer faceplate?” answer: “Use plumber’s putty or a proper skimmer gasket kit. Standard silicone sealant is not recommended for the skimmer faceplate because it doesn’t adhere reliably to wet or rough surfaces and degrades faster in chlorinated water. Pool-grade putty or a rubber gasket provides a longer-lasting seal.”

Related Reading

• How to Maintain Your Home’s Exterior Year-Round
• How to Fix a Leaky Outdoor Faucet
• How to Install a Sump Pump