How to Replace Curved Greenhouse Glass

Greenhouses are an excellent addition to any property, allowing you to grow an array of vegetables, herbs, flowers, and other plants in a weather-safe and controlled environment year-round.

Simply put, it’s a place you can keep slightly warmer in the winter, which your plants appreciate.

But, of course, these valuable structures need to be adequately maintained to function properly, which entails replacing glass panels for your greenhouse as needed. 

While this can be relatively straightforward for simple square panels, replacing curved greenhouse glass panels can be a trickier process due to their unique and potentially complex forms. 

To help simplify things, we’ll give you clear insight into how to replace these curved panels, also known as greenhouse glazing, so that you can keep your greenhouse up, running, and growing without issue.

What Kind of Curved Glass Does Your Greenhouse Have?

One of the first steps in figuring out how to replace your curved greenhouse glass panels is to determine what they’re made out of.

Historically, greenhouses were primarily constructed using single-pane glass and metal and were often known as glasshouses. Nowadays, modern greenhouses are usually made of synthetic materials, which can be more durable and easier to manufacture, such as acrylic or polycarbonate.

However, double-plane and tempered glass are also used.

Each material has unique advantages and disadvantages, so it’s important to weigh these factors and determine what works best for your situation.

Single-pane glass was the most common material used in early greenhouses, but it lacks basic heating sufficiency and can be subject to sealing issues. That was later replaced by double-pane glass, which offered greater heating efficiency and was aesthetically pleasing, but was often more expensive. 

Nowadays, options like acrylic, tempered double-pane glass, and polycarbonate are commonly used and can be molded and curved. It creates a great aesthetic but often perplexes gardeners when they have to figure out how to replace the curved glass in their greenhouse.

• Tempered double-pane glass is the nicest looking and an incredibly durable option, but it’s not as strong as polycarbonate or acrylic.
• Acrylic is more durable than any glass option, but it is also not as durable as polycarbonate and is often more expensive.
• Polycarbonate offers some of the best durability and is cheaper than most other options but is often less aesthetically pleasing than glass options.

If you’re looking to replace individual panels on an existing structure, try to determine the manufacturer of your greenhouse and see if they produce replacement panels. If the company no longer produces panels, you may be able to find a third-party company that actively makes the ones you need, or that can fabricate them as needed.

Determining the Right Kind of Curved Glass Replacement to Buy

Finding the right curved glass replacement for your greenhouse can be complicated, but thankfully, it doesn’t have to be.

If possible, you will want to determine the make and model of your specific greenhouse, as this will help you find your exact panel for sale, possibly directly from the original manufacturer. However, if you can’t figure this out or if your greenhouse was custom-built, don’t worry; you can still determine the right kind of curved replacement glass to buy.

First, you want to figure out the basics, such as the size and dimensions of the panel. These are the basic measurements you’ll use to help you narrow down your search. Next, you’ll want to determine the curvature of the pane you’re replacing.

You can do this by measuring the girth, or the radius of the panel’s bend, starting from the beginning of the curve to the end. Along with the basic dimensions, you’ll use this information to either buy a replacement from the original company, a third-party, or reach out to a nearby glazier for custom fabrication.

An important thing to keep in mind is the material the rest of your panels are made of, as this can greatly impact how much you’ll pay for a replacement pane. It will also help you learn how easy it will be to source.

Acrylic and polycarbonate panels are often the cheapest and easier to find, while finding custom-cut glass options may be more complicated and expensive. 

How Much Will Does Curved Greenhouse Glass Cost?

On average, expect to pay between $50-$100 per square foot for basic glass whether it’s curved or not. In contrast, you can get basic polycarbonate covering for about $1 per square foot and twin-wall polycarbonate for up to $2.20 per square foot from the right company. A curved tempered double-pane glass panel for a greenhouse can run hundreds of dollars for a single panel, depending on the size and shape needed.

Can You Curve the Glass Yourself?

While there are forms of greenhouse glazing materials that are more malleable than others, the answer to this question is no in most cases.

When it comes to glass in particular, there’s no way for the average person to bend the panel to the shape they need with the tools they have access to. Even comparable plastic alternatives like polycarbonate aren’t going to be able to be heated and formed to shape with the standard toolsets available to the average homeowner.

Technically, you could use a material like cheap single-layer poly as a way to cover a panel and help prevent the elements from getting into your greenhouse. This plastic sheeting can easily be draped over and pinned into place, so you can technically curve the panel yourself. However, this material is not very thermally efficient and is subject to tearing in extreme winds or weather.

Ideally, you should reach out to the original manufacturer or an associated company to get a proper replacement panel. However, if that’s not feasible, try searching for a local glazier who can custom-cut and fit a panel for your greenhouse.

How to Remove Curved Greenhouse Glass

Removing curved greenhouse glass can be trickier than basic panels, and you must take extra care and consideration for any cracks in the panel, as well as the materials the panel and greenhouse are made from. To remove curved greenhouse glass or plastic panels, keep the following in mind:

Wooden Greenhouses

• Use pliers to remove the glazing pins that are in place. This will give you direct access to the panel you want to replace.
• Remove the panel you want to replace. If there is a pane that overlaps above it, remove that pane first to gain proper access.
• Remove the existing putty from the edges of the pane. If there is any stuck to the wooden frame, gently use a chisel to remove it, taking care not to damage the wood.

Metal Greenhouses

• Remove the glazing clips that hold the panel in place, which will allow you access to the panel itself.
• Remove the panel you want to replace. If there is an overlapping pane, remove it first for easier access.
• Clean the seal strip inside of the frame and check it for any damage. Replace the strip as needed if any damage is found.

Installing the New Curved Glass/Plastic

Installing a curved greenhouse glass or plastic panel can seem intimidating if you’re unfamiliar with the process, but with a little guidance, it’s actually fairly straightforward. To install curved greenhouse glass or plastic panels, keep the following in mind:

Wooden Greenhouses

• Apply a fresh layer of putty around the sides and bottom of the frame, but leave the top untouched.
• Gently set the new panel into place. Try to take care not to squish the putty around.
• Insert the glazing pins to hold the panel in place. Use a small pin hammer to set the pins in place properly.

Metal Greenhouses

• Apply a fresh seal strip to the frame if needed.
• Gently install your new panel, and ensure it is secure before proceeding.
• Replace the glazing clips for the panel. Make sure there is a clip every 12 inches.

Finding Curved Greenhouse Glass Replacement Companies

After reading this article, it’s easy to see that replacing your greenhouse glass, curved or otherwise, isn’t really that complicated. All you need is a few simple tools, the right replacement panel, and the proper knowledge behind you.

Of course, finding the right replacement panel for your greenhouse can be relatively straightforward for common options or a much trickier affair if you have a custom-made one. If you know the make and model of your particular greenhouse, getting a replacement can be as easy as reaching out to the original company or placing a simple online order.

If the company is no longer in business or you can’t readily find a replacement from them, you may be able to find a third-party company that still produces them. While these may not be 1-to-1 replacements in some cases, these companies present an affordable alternative to reaching out for custom fabrication.

On the other hand, if you cannot find the original company or a third party that produces the panels, you may have to reach out to a nearby glazier to have them custom-craft a replacement for you.

Useful Video on Polycarbonate vs. Glass Greenhouses

Over it?

Have you read all this and decided you just want to buy a new greenhouse? Take a look at our buying guide for greenhouses if that’s the case. We also have some recommendations for a small greenhouse that can feed a family of 4.