Polycarbonate vs. Laminated Glass

 The Case of the Polycarbonate Pool Project


Dear Glass Detective,

I’m thinking of using ¼-inch or 3/8-inch polycarbonate rather than laminated glass for a deck railing system. The deck is about 10 feet above a pool and I don’t want to take any chances of damage should furniture, etc. hit the glass in a storm while I’m away.  I’m willing to tolerate a little scratching in return for safety.  The polycarbonate is coated on both sides for Ultra Violet (UV) light resistance. Is there any reason not to use polycarbonate in this kind of system?




Dear Bob,

Thank you for making contact with the Glass Detective with your question as to whether or not polycarbonate might be a good substitute for laminated glass in a deck railing system.

First, let’s talk about what polycarbonate is and how it differs from glass. Polycarbonate is very similar to glass to the naked eye. It looks like glass, it can be cut to the same shapes, sizes and thicknesses as glass, and it is sometimes used for the same purposes as glass such as a replacement for windows. The difference though is that it’s not glass at all. Polycarbonate is a type of plastic. This comes with its own advantages and disadvantages. Polycarbonate does not have the same optical clarity as glass and is softer, so it scratches more easily. Over time it can accumulate marks, marrings, dents and even take on a foggy look. However, a hard coating can be applied to polycarbonate that will help resist scratching. On the plus side, it is stronger than glass—approximately 250 times stronger. This makes it ideal for places where weight-bearing or security is a concern.

Given the information above, my response is that you seem to have thought this out a bit and the reasoning behind your pending decision to use polycarbonate in your pool deck instead of laminated glass makes sense to me. Your exact question was “is there any reason not to use polycarbonate in this kind of a system?” So my exact answer would be “no”. HOWEVER (And don’t you just love it when someone answers your question but then adds “however”?), you will need to install the polycarbonate correctly. Because polycarbonate expands and contracts more than glass, you want to make sure you fabricate and install the polycarbonate in keeping with the manufacturer’s recommended tolerances and procedures. Your polycarbonate supplier can help you with installation guidelines if you explain the installation type (framing and so forth) and provide them with the sizes of the frames into which you will be installing the polycarbonate. Please also remember to purchase and use an appropriate polycarbonate cleaner (not a glass cleaner) on the polycarbonate, again in keeping with the cleaner manufacturer’s recommendations. And remember, too, to check the applicable codes for decks and railings in our jurisdiction.

Thank you once more for contacting the Glass.com Glass Detective and we wish you well with your project.

The Glass Detective attempts to answer all questions accurately but cannot be held liable for any information provided or omitted.  You should always work with a licensed, insured and reputable glass shop that can assess your specific needs and local building codes and offer professional services. Never attempt to cut, install, or otherwise work with glass yourself. The Glass Detective answers questions on an informational basis only.

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