Underwater Window Installation For Tiled Pools [2025]

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Installing an underwater window in a tiled pool can often feel complex, though a great feature to make the pool stand out.

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Whether you’re building a private luxury pool or a commercial wellness space, a properly installed underwater window can turn an ordinary swimming area into an extraordinary visual experience.

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As someone who’s worked in pool construction and underwater window building for over 20 years, I’ve seen both the stunning results of expert installations and the costly mistakes when shortcuts were taken. 

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In this article, I’ve tried to put the whole process of installing underwater windows in a swimming pool into a step-by-step guide. It will help you avoid mistakes, and confidently approach your next tiled pool project.

So let’s begin.

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TL;DR – Key Takeaways

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• Underwater window installation in tiled pools requires precision, waterproofing, and correct framing.
• Proper sealing with slurry and sealing tape prevents leaks and structural failures.
• Always protect glass during construction to avoid scratches or cracks.
• A waterproofing test is mandatory before tiling to ensure zero leakage.

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Partnering with a specialist (like Hammerhead Pools) guarantees safe, lasting results.

Now let’s get into the details.

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Some Facts About Underwater Windows For Tiled Pools

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Before I start with the step-by-step guide, let me share a bit of knowledge in case you are newly engaged about underwater windows in pools.

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If you want, you can directly move to the section on the step-by-step guide. No pressure. 

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What Makes Tiled Pools Unique for Window Installation?

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Unlike fiberglass or concrete shells, tiled pools have joints, grout lines, and multiple waterproofing layers. That makes precision sealing around underwater windows absolutely critical. Any weak point can cause leakage later.

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Materials Commonly Used in Underwater Windows

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• Laminated Safety Glass – highly durable, resists scratches, provides clarity.
  
  
• Acrylic – lighter and clearer, but more prone to scratching.
  
  
• Steel Frames – provide rigid support and anchor into concrete.
  
  

Each material is chosen based on depth, window size, and design vision.

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Common Challenges in Tiled Pools

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• Maintaining 100% waterproof seals despite tile expansion/contraction.
  
  
• Ensuring the glass thickness matches pool depth to handle hydrostatic pressure.
  
  
• Preventing cracks or leaks from poor alignment of the frame.

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Benefits of Adding an Underwater Window

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• Aesthetic luxury – pools with windows instantly look high-end.
  
  
• Safety – allows parents or staff to visually monitor swimmers underwater.
  
  
• Real estate value – homes and facilities with underwater views command higher appeal.

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Ok, enough with the boring stuff. Now let’s get into the key step-by-step process or underwater window installation for tiled pools.

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Step-By-Step Guide to Underwater Window Installation in Tiled Pools

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These are simply steps I follow. You just need to make sure you are extra careful in executing all of them for better output.

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Let’s get started.

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1. Preparing the Pool Wall Opening

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Before you even touch the window frame, you need precise wall dimensions (often labeled A, B, C, D in technical manuals). These ensure your underwater window fits flush with the pool wall.

• Use a grinder to clean and remove loose concrete.
  
  
• Double-check measurements against the manufacturer’s specifications.
  
  
• Decide on orientation: the poolside (wet side) and the dry side are often marked with stickers.
  
  

Pro tip: Misalignment at this stage is the #1 cause of water pressure issues later on.

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2. Placing and Aligning the Window

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Moving the window into position can be done manually for smaller units or with a crane for larger glass panes.

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• Support the frame with blocks to keep it centered.
  
  
• Drill holes at pre-marked slots on the frame.
  
  
• Insert dowels and hammer them into place to secure the structure.
  
  

Note: The dry side must be perfectly flush to avoid gaps when sealing.

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3. Protecting the Glass

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Before waterproofing begins, cover the glass surface with cardboard or protective film. This prevents accidental scratches during sealing, slurry application, or tiling.

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4. Waterproofing the Frame & Wall Joint

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This is where most tiled pool projects succeed or fail.

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• Clean the steel frame with benzene or recommended cleaner.
  
  
• Apply a 2mm layer of waterproofing slurry to the frame and 50 cm into the adjacent wall.
  
  
• Place sealing tape over the slurry, ensuring half covers the frame and half covers the wall.
  
  
• Repeat slurry + tape application in multiple layers for maximum strength.
  
  

Finish with one last coat of slurry over the tape.

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5. Supporting & Sealing the Dry Side

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Check for any visible gaps on the dry side. If you see cavities, fill them with cement to reinforce structural strength. A solid seal here ensures the window can withstand long-term hydrostatic pressure.

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6. Conducting the Waterproofing Test

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Before tiling, perform a water test:

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• Apply temporary black waterproof material to the remaining pool walls.
  
  
• Fill the pool with water and leave it for 24–48 hours.
  
  
• Inspect for leaks around the window frame.
  
  

If there’s leakage, repair immediately before moving forward.

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7. Tiling Around the Underwater Window

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Once waterproofing passes the test, continue with standard tiling. Make sure the tiles align neatly with the window frame to maintain both aesthetic appeal and sealing integrity.

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Why This Process Is Crucial

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Unlike acrylic windows in prefabricated pools, tiled pools require precision engineering. Water pressure against the glass is relentless. If sealing isn’t done right, leaks will show up months later and repairs will cost 2–3x more than the initial installation.

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By following this methodical approach, you will be able to prevent water leakage, extend the life of both pool structure and window., and ensure a luxurious, crystal-clear underwater view.

Final Thoughts

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Installing an underwater window in a tiled pool is both a science and an art. From preparing the frame to testing waterproofing, every step demands attention to detail. When executed properly, the result is a breathtaking view that lasts for decades.

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Expert Underwater Window Installation

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Thinking of adding an underwater window to your tiled pool? Don’t leave it to guesswork. Our team at Hammerhead Pools has 20+ years of hands-on experience with underwater windows across residential, commercial, and luxury pools. You may reach us for a free quote.

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Or if you have questions about what you learned in this article, simply leave a comment and I will respond from my years of experience.

Cheers!

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FAQs

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1. Can I install an underwater window in an existing tiled pool?

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Yes, but it’s more complex than a new build. The wall must be restructured, reinforced, and resealed. Always consult a specialist before retrofitting.

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2. How thick should the underwater window glass be?

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It depends on the pool depth and size of the window. Typically, laminated safety glass is used with thickness ranging from 25mm to 50mm.

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3. How long does underwater window installation take?

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On average, 3–5 days for new pools, depending on curing and waterproofing tests. Retrofitting may take longer.

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4. Do underwater windows require maintenance?

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Minimal. Routine cleaning and periodic inspection of seals are usually enough. Proper initial installation reduces maintenance significantly.

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5. Are acrylic or glass underwater windows better for tiled pools?

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Glass is more durable and scratch-resistant, while acrylic offers better clarity but scratches more easily. For tiled pools, glass is often preferred due to structural reliability.

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6. Can underwater windows crack under pool pressure?

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If properly engineered and installed, no. Windows are designed to withstand pressure far beyond typical pool loads. Cracking usually occurs only from improper installation or impact damage.