Both grid drains and pop-up drains are types of drainage systems used to remove water from pools and spas. The main difference between the two is how they are installed and how water flows into them.
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What is a Grid Drain?
A grid drain, also sometimes called a passive drain, is a type of drain that is installed flush with the floor of the pool or spa. It consists of a frame and grate that sits level with the floor, with an outlet pipe underneath that connects to the main drainage pipes. Water simply flows through the grate and down the pipe.
Grid drains are the more common and traditional type of pool/spa drainage system. They provide an unobtrusive way to drain water, as they sit flush with the floor and don’t protrude up into the pool. This creates a smooth surface and reduces the risk of scrapes or injury from a protruding drain.
Grid drains rely on gravity to remove water. As water pools on top of the grate, it will naturally flow down through the holes and into the piping below. The size and number of holes in the grate determines the flow rate. More and larger holes allow water to drain faster.
Multiple grid drains are usually installed on the floor of pools and spas to allow water to drain evenly from all areas. They are often installed in the deepest parts to facilitate thorough draining. The grates can come in different shapes like circles, squares, and rectangles.
Advantages of Grid Drains
- Flush with floor for safety and smooth surface
- Unobtrusive appearance
- Can be installed anywhere on pool floor
- Rely on gravity so no power needed
- Less prone to clogs compared to pop-up drains
Disadvantages of Grid Drains
- Drain more slowly than pumps
- Can get covered by debris reducing flow
- Not visible when draining, harder to monitor
- Require manual cleaning to remove debris
What is a Pop-Up Drain?
A pop-up drain functions a bit differently than a grid drain. As the name suggests, it pops up above the floor when activated. A pop-up drain consists of a housing that sits flush in the floor, and a moveable cylinder inside with holes in it. When it’s time to drain the pool, the cylinder rises up out of the housing to protrude above the floor, allowing water to flow in through the holes.
Pop-up drains are connected to the main drain pipes, but also have a pump that controls the lifting mechanism. So when it’s time to drain, the pump activates and lifts the pop-up cylinder above the floor. Water can then rapidly flow into the holes and down the pipes. When draining is complete, the pump lowers the cylinder back into the housing so it sits flush again.
The main advantage of a pop-up drain is speed. It can drain a pool significantly faster than just using passive grid drains. This makes cleaning and maintenance more convenient. Pop-up mechanisms also incorporate anti-entrapment designs for improved safety.
Pop-up pool drains are frequently installed in combination with grid drains. The pop-up can be activated when needed for fast draining, while the passive grates allow continual unobtrusive drainage.
Advantages of Pop-Up Drains
- Very fast draining with pump
- Anti-entrapment safety features
- Visible above floor when active
- Can supplement grid drains
Disadvantages of Pop-Up Drains
- More expensive than grid drains
- Require electricity for the pump
- More prone to clogs from debris
- Protrudes above floor when active
- Mechanism requires maintenance
Grid Drain vs Pop-Up Drain Comparison
Here is a summary comparing grid drains vs. pop-up drains for pools and spas:
| Feature | Grid Drain | Pop-Up Drain |
|---|---|---|
| Installation | Flush with pool floor | Flush housing with pop-up cylinder |
| Drain Method | Passive gravity drainage | Pump lifts pop-up mechanism |
| Drain Speed | Slower passive drainage | Very fast active drainage |
| Visibility | Not visible when draining | Visible above floor when active |
| Safety Features | Flush with floor | Anti-entrapment design |
| Prone to Clogs | Less prone to clogs | More prone to clogs |
| Maintenance | Manual debris cleaning | Mechanism requires maintenance |
| Electricity Needed | No | Yes, for pump |
Types of Grid Drains
There are a few different types and designs of grid drains that can be installed in pools and spas:
Simple Frame and Grate
The most basic is a simple plastic or metal frame with a grated cover. The grate allows water to flow through into the outlet pipe below. These simple drains are inexpensive but are less aesthetically appealing.
Tile Over Grate
For a more seamless look, tile can be installed over the grate. This allows the grid drain to blend in with the pool floor. Tile matching the pool floor is cut to size and bonded over the grate. Water flows through the grout lines.
Custom Design Grates
For a more decorative look, custom grate designs are available. These can be simple patterns or logo designs that add visual interest.
Perimeter Overflow Drains
These long drains run along the perimeter of pools. They catch water as it overflows and drains it below. This creates a smooth, infinity edge look.
Types of Pop-Up Drains
Pop-up pool drains also come in a few different designs:
Active Main Drains
These act as the main drainage system for the pool. They are large drains, usually 12-24 inches, that rapidly drain water when activated.
Multiple Point Drains
Some pop-up drain systems consist of many smaller point drains spread around the pool floor. This improves safety and drainage.
Water Feature Drains
Smaller pop-up drains can be used as part of water features. When not draining, they stay flush with the floor.
VGBA Compliant Drains
All pop-up drains installed for pools and spas today must meet VGBA (Virginia Graeme Baker Act) standards for safety. This regulates the cover design and suction strength.
Cost Comparison
In general, grid drains are the more economical option for pool and spa drainage. Here are some typical price ranges:
- Grid drain – $80 to $200 each
- Simple pop-up drain – $300 to $600 each
- Elaborate pop-up drain system – $2,000 to $4,000
Of course, exact pricing will vary depending on factors like the number of drains needed, chosen materials, and local labor costs. Installation is also a significant portion of the total project cost. But grid drains provide effective drainage at the lowest material cost in most cases.
Installation Tips
Proper installation is critical to ensure grid drains and pop-up drains work correctly. Here are some installation tips:
Hire a Professional
It’s highly advisable to hire an experienced pool contractor to install the drains properly. Improper installation can lead to leaks or other problems.
Drain Location
Drains should be positioned in the deepest areas spaced around the pool perimeter. This allows for thorough drainage. Building codes often regulate locations.
Proper Slope
The drain pipes must slope downward at a minimum angle to allow water to flow freely to the main drain line.
Clean Piping
All drain pipes should be thoroughly flushed before connecting final fittings. Debris left inside can clog drains.
Seal Joints
All joints and connections in the drain pipes should be properly sealed and tested for leaks before burial.
Backfill Carefully
Pipes must be completely supported and surrounded with drainage aggregate. Soil backfilling should be done carefully around pipes.
Electrical Connection
For pop-up drains, the pump must be properly wired and connected to power. Test thoroughly before completing project.
Maintenance Tips
Like any pool system component, drains require regular maintenance. Here are tips for keeping them working properly:
Visually Inspect
Check drains frequently for any signs of damage, leaks, or malfunction. Repair any issues immediately.
Clear Debris
Remove any leaves, sediment or other debris that may partially block drains and reduce flow rate.
Check Flow Rates
Test drain flow rates periodically. Noticeably slower drainage could indicate a clog starting.
Clean Grates
Thoroughly clean grid drain grates with a wire brush as needed to clear holes and maintain flow.
Test Pop-Up Mechanism
For pop-up drains, periodically activate the mechanism to ensure it is lifting properly.
Repair Sealants
Reapply plumber’s putty or caulk around drain connections if any gaps appear that could leak.
Conclusion
While grid drains and pop-up drains both effectively remove water from pools and spas, they utilize different designs and installation methods. Grid drains are more common for their simplicity and lower cost. Pop-up drains provide faster, active drainage but at higher initial cost. Proper installation and ongoing maintenance are key to ensuring problem-free operation of pool and spa drainage systems.