If you’re a pool owner preparing your swimming pool for the off-season, you’ve probably come across a common question: should a winter pool cover touch the water? This seemingly simple question has generated a number of opinions, DIY tips, and forum discussions. The answer isn’t always black and white — and for good reason.
Proper winterization of your swimming pool can mean the difference between smooth reopening in spring and expensive damage requiring major repairs. One of the most crucial elements in this process is selecting the right winter cover and installing it correctly. Understanding whether your winter pool cover should be submerged or suspended above the waterline is key to effective pool winterization.
In this comprehensive guide, we’ll explore what pool experts recommend, the types of winter covers available, and why submersion—or not—might matter depending on your pool type, climate, and water conditions.
Understanding Winter Pool Covers
Winter pool covers serve several essential functions in preserving your pool when it’s not in use. Let’s understand first what a winter pool cover is and what it’s designed to do.
What Is a Winter Pool Cover?
A winter pool cover is a heavy-duty, durable cover specifically designed to protect your pool during the colder months. It prevents debris from entering the water, reduces evaporation, protects the pool structure from freeze damage, and helps maintain water balance as much as possible over the winter season.
There are two primary types of winter covers:
– Solid Covers
– Mesh Covers
Solid Covers
Solid winter pool covers are made from a continuous sheet of material — often vinyl-coated polyester — designed to keep water out. These are typically secured with water bags or anchors and are installed on top of the water’s surface.
Because they are water-resistant, solid covers are especially beneficial in preventing rainwater or melting snow from entering the pool. However, they require pumping off accumulated water to avoid damaging the cover or placing undue stress on the pool walls.
Mesh Covers
Mesh winter pool covers, on the other hand, are woven with small holes that allow rain and snowmelt to drain through, significantly reducing the need for manual water removal. These covers are usually made from UV-stabilized polyethylene or similar materials and are often stretched tight across the pool with fasteners.
They are lighter in weight and easier to maintain over the winter, as long as the water level in the pool is kept at the appropriate level to avoid strain and allow proper drainage.
Why Installation Matters
The way a winter cover is installed — whether it’s touching the water or not — can have a significant effect on how well your pool survives the winter season without incident.
But to better understand this, let’s look closer at why submersed installation or a “water pillow” method is sometimes used — and whether it’s actually necessary or even advised in most cases.
To Touch or Not Touch — That Is the Question
So, should a winter pool cover — especially a solid type — actually touch the water? The short answer is: Yes, in most cases, it should. But the long answer depends on a range of environmental and structural factors.
What Happens When the Cover Touches the Water?
By lowering your water level so the cover lies flat on the water’s surface, and then using water tubes (also called water bags or water pillows) to hold it in place, the objective is to ensure the cover forms a tight, air-tight seal over the pool.
This practice does two key things:
- It minimizes water movement inside the pool, especially during freezing temperatures.
- It prevents the water underneath from freezing in such a way that it damages the pool tiles, edges, or coping sealants.
What Happens When the Cover Is Suspended?
Conversely, if your winter cover is above the water line, there will be air space between the water and the cover. This can cause:
- Unnecessary movement of water when high winds hit the pool or when the cover flaps.
- Potential for water to freeze, then expand, and push up against the pool shell.
- Increased risk of tiles becoming loose or cracked due to pressure and freeze damage.
This approach is typically not recommended, especially in regions where temperatures drop below freezing.
Climate Considerations and Regional Differences
Whether or not a winter pool cover should lie on the water depends heavily on the environment and the average winter conditions in your area.
Freeze-Prone Regions
If you’re located in an area with consistent temperatures below 32°F (0°C) for a significant portion of the winter, leaving a gap between the cover and water can be risky. The air space between the cover and the water can cause unpredictable freezing and pressure that results in damage.
In these places, touching the water is essential, and doing so with water bags around the cover’s perimeter helps anchor it securely.
Types of Damage from Incorrect Installation
- Cracked or dislodged pool tiles
- Heaved coping and cracks in the surrounding deck
- Water line damage due to pressure from water expansion
- Damaged skimmer or return lines
Warmer Regions (No Freezing)
Conversely, in non-freeze zones, where winter water temperatures neither reach the freezing point nor stay low for long, touching the water isn’t as critical. The key here is to keep the cover taut and secure, protecting the pool from leaves, dust, and external contamination.
In milder climates, drain covers just enough to stay below the skimmer mouth, and install the winter cover without needing to let it make full contact. Even here, however, manufacturers usually recommend installing solid covers with water pillows wherever possible. It offers a longer lifespan and superior protection against evaporation.
Types of Winter Pool Covers: Which Needs to Touch Water?
Each type of winter pool cover has its own installation needs. Recognizing the differences will help you make an informed decision about whether the cover should touch water.
Solid Winter Pool Covers
These are the most commonly used type in freezing climates. Solid covers must lie on the surface of the water to avoid damage from ice movement and build-up. They require water bags or a floating pillow system to keep them secured and prevent them from blowing off or tearing from wind pressure.
Installation Tips for Solid Covers:
- Lower the water level to about 12–18 inches below the skimmer, so the water pillow sits on the pool surface.
- Place water bags around the perimeter to hold the cover down and minimize flapping.
- Use a leaf net as an additional layer if needed, especially in a fall-heavy leaf area.
Mesh Winter Pool Covers
Mesh covers allow water to permeate through them, meaning that they should not lie directly on the water’s surface. Instead, they must be installed on a support frame or across a slightly lowered water level — around 4–6 inches below the tile line — so that water can pass through without accumulating on the surface.
Why Mesh Covers Shouldn’t Lie Flat on Water:
- Mesh covers work best when stretched tightly to allow precipitation to drain through the holes.
- If a mesh cover remains submerged for long periods, it can promote algae growth, discoloration, and increased debris build-up.
- The drainage mechanism is undermined if the cover lies on the water with no tension.
So, the type of cover dictates how it should be installed: solid covers generally must lie directly on water, mesh ones must remain above.
The Science Behind Submersion: Physics and Winter Pool Protection
To understand why experts recommend touching the water with solid covers, let’s delve just a bit into the physics and chemistry of freezing water and pressure dynamics.
Why Ice Expansion Is Dangerous for Pools
Water is one of the few substances that expands when frozen, and that increase in volume can create intense pressure inside the pool structure. If the cover is not installed correctly, this pressure — combined with movement — can cause severe structural damage.
When a solid cover is laying directly on the water’s surface, it acts as a cushion or shock absorber as the water begins to freeze and expand. The water pillow method (using water-filled bags on the cover) essentially compresses the expanding ice, absorbing some of the energy and limiting contact expansion with the pool walls.
The Role of Air Pockets in Freeze Damage
Leaving a cover suspended with an air space beneath it may seem harmless, but air and ice don’t mix safely in an enclosed structure like a residential pool. When water freezes, the trapped air can cause uneven freezing, pressure shifts, and localized damage. It also leads to fluctuations in water level, which may cause undue stress on pool filters or drain lines.
What Happens Underground? Water Table and Hydrostatic Pressure
In cases where groundwater levels rise during winter, especially in well-drained or rainy regions, a fully detached pool cover can cause hydrostatic pressure issues. When water cannot escape, upward force from ground-level water may displace the pool structure or crack the floor.
To avoid this, use a solid winter cover in conjunction with a hydrostatic relief plug (if applicable), ensuring air space is properly managed without trapping moisture inside the pool.
Installation Tips: Cover Touching vs. Suspended Covers
If you’re still unsure which installation method to choose, let’s take a closer look at when to touch the water vs. when to stay elevated, and how to maximize the lifespan of your cover and pool.
For Touching the Water
Best for:
- Regions with regular and prolonged freezing
- Use with solid winter covers
- Protecting in-ground vinyl liner pools from stretching and damage
Installation Steps:
- Lower the water level 12 to 18 inches below the skimmer (for an average in-ground pool).
- Install the winter cover securely across the pool edge, using water bags for anchoring.
- Fill water bags partially with water and place them around the edges of the cover.
- Allow water bags to drain any collected rainwater, and make sure they are tied down tightly.
For Suspended Covers
Best for:
- Warmer climates with no hard freezes
- Use with mesh cover types
- Seasonal outdoor pools in places with minimal leaf load
Installation Steps:
- Drain water 4–6 inches below the tile line, or as per manufacturer instructions.
- Solidify the cover with a support system or anchors around the edge.
- Ensure the cover has sufficient tautness to allow water to run off through the mesh.
- Check the cover occasionally for debris or water pooling issues.
Potential Pitfalls and What Homeowners Should Avoid
While your goal is to protect your pool, improper installation practices can sometimes sabotage its integrity. Here are some common mistakes to avoid when installing your winter pool cover.
Mistake #1: Incorrect Water Level
- Too high: water may freeze and push under the cover, causing it to detach or rip.
- Too low: air pockets can cause ice damage and structural stress.
Mistake #2: Using the Wrong Cover Type for Your Climate
Using a mesh cover where there’s heavy freezing is a common error. Avoid mesh without proper freeze considerations.
Mistake #3: Failing to Balance Water Chemistry Before Closure
Even under a cover, untreated water can become a host for algae, bacteria, and scaling deposits. Balance the water first to avoid costly problems in spring.
Conclusion: When Should a Winter Pool Cover Touch the Water?
So, circling back to our original question: should a winter pool cover touch the water?
For solid winter pool covers in cold climates, absolutely yes. The cover should be installed to lay flat over the water’s surface, with water pillows used for anchoring and pressure distribution. This protects the pool from ice damage, water movement, and pressure build-up that could lead to costly structural issues.
For mesh covers in warm climates or milder winters, the cover must remain slightly above the water surface to allow for proper drainage and prevent unwanted algae growth or debris entrapment.
While the answer varies slightly based on materials and climate, following manufacturer recommendations for your specific pool and cover type can prevent problems and ensure your swimming pool is in excellent shape come spring.
Table Summary: Winter Pool Cover Installation by Type and Climate
| Pool Cover Type | Recommended Installation | Climate Suitability | Water Contact |
|---|---|---|---|
| Solid Cover | Lying flat on water with water bags | Freezing climates | Yes – should touch surface |
| Mesh Cover | Tightly suspended above water | Non-freezing climates | No – should remain elevated |
Final Thoughts
There’s no “set it and forget it” approach to winter pool covers. Making sure the installation is correct can be the difference between enjoying your pool in May and spending a few thousand dollars on repairs. If your pool is solid plastered, vinyl-lined, or in-ground concrete, the details matter.
So whether you’re in frigid New York or sun-drenched Phoenix, always consider your climate and pool design before picking your cover type and installing. It’s worth the time and effort.
By answering the question, should a winter pool cover touch the water?, now you’re not only informed — you’re ready to winterize your pool confidently and correctly.
Should a winter pool cover touch the water?
Yes, in most cases, a winter pool cover should touch the water. Allowing the cover to rest directly on the water’s surface helps prevent the formation of ice from causing damage to the pool walls. When water freezes, it expands, and if the cover is suspended above the water, this pressure can push the cover downward, trapping water between the ice and the cover, which may lead to structural stress or damage.
However, it’s essential to note that the type of pool and cover matters. For example, in some in-ground pools, especially those in colder climates, a solid winter cover should make contact with the water to provide proper support and ice protection. On the other hand, if you’re using a mesh cover, it’s generally designed not to touch the water, as it allows for water drainage and may not require direct contact to function properly.
What are the different types of winter pool covers?
There are primarily three types of winter pool covers: solid vinyl covers, mesh safety covers, and thermal blankets. Solid vinyl covers are designed to prevent debris and water from entering the pool and are best suited for areas with significant winter precipitation. Mesh safety covers allow water to pass through but keep the pool secure from accidental falls, making them popular in safety-conscious households.
Thermal blankets, often used in conjunction with other covers, are ideal for minimizing heat loss and protecting against light frost. Each type of cover has specific installation guidelines. For example, vinyl covers generally should touch the water for maximum protection, while mesh covers typically need to be slightly elevated above the water level to allow for proper drainage and ice movement.
What happens if a solid winter cover is not in contact with the water?
If a solid winter cover is not in contact with the water, ice formation during the winter can create significant pressure within the pool. As the water freezes and expands, it can push upward and form a layer of ice that may lift the cover, trap meltwater underneath, and create a situation where this trapped water freezes as well, compounding the pressure on the pool structure.
This situation can lead to damaged pool walls, cracked tiles, and even issues with the filtration system. By ensuring that the solid cover is in direct contact with the water, you allow any expanding ice to rise against the cover, which remains anchored, distributing the force more evenly and reducing the potential for damage to your pool.
Why not let a mesh cover touch the water?
Mesh covers are designed to drain water through their porous surface, which makes it unwise to let them touch the water level directly. If a mesh cover is in contact with the water, freezing and thawing conditions can trap water on top, leading to standing water that may become a safety hazard and cause undue stress to the cover and pool structure.
Additionally, mesh covers are often tightened over the pool during winterizing to maintain their integrity and safety. Keeping them above the water level allows any rain or snowmelt to pass through without collecting underneath, minimizing damage risks and facilitating easier spring cleanup. Therefore, using a leaf net or support system to keep the mesh cover suspended slightly above the water is recommended.
How do I ensure the winter cover is installed correctly?
Proper installation of a winter pool cover begins with a clean, balanced pool to prevent algae growth and staining. For solid covers, water level adjustments are critical—lowering the water level to just below the skimmer or allowing the cover to touch the water, depending on the manufacturer’s instruction and cover design. Use water bags, springs, or a cover pump to secure the cover and manage water accumulation.
Mesh covers, on the other hand, require a snug but elevated fit. A support system like a leaf net or air pillow can be used to create a slope for water runoff and prevent water from pooling on the cover. Use proper anchoring systems such as water bags or anchors around the perimeter to secure the cover firmly. Always follow the specific guidelines provided by the manufacturer to ensure safe and effective installation.
Do I need to use an air pillow under the winter cover?
Using an air pillow under a winter pool cover is highly recommended, especially if you live in areas where freezing weather is common. The air pillow floats on the water surface and creates a space between the ice and the pool walls. This helps to absorb the pressure caused by the expansion of freezing water, preventing potential damage to the pool structure.
When the solid cover is installed and secured properly, the air pillow works in tandem by allowing room for the ice to expand upward without exerting force on the pool sides. This is especially important for in-ground pools, where structural integrity is vital. In contrast, mesh covers typically don’t require an air pillow since they are designed to remain taut and elevated above the water level to facilitate proper drainage.
Can a winter cover cause damage to the pool if improperly installed?
Yes, a winter cover can cause significant damage to a pool if it is not installed properly. For solid covers, an improperly tensioned installation can lead to water and debris collecting on top, increasing the risk of tearing or allowing mold and algae buildup below. Moreover, if the cover isn’t in contact with the water in colder climates, freezing ice can expand and put pressure on the pool walls and equipment.
Mesh covers can also be problematic when improperly installed. If they are too loose or allowed to sag into the water, freezing and thawing cycles can lead to standing water collection or create a dangerous situation where people or animals might fall into the pool. Ensuring that both solid and mesh covers are correctly fitted, anchored, and maintained throughout the winter months is crucial to protecting the pool and preventing expensive repairs. Always refer to the manufacturer’s instructions or consult a professional for the best results.