If you are building a greenhouse or a cold frame, you can choose between a number of materials to complete your project, and glass and perspex are two of the main materials to consider. Whilst glass is the traditional choice, perspex may offer more advantages. Here are just a few of the advantages perspex offers over glass when it comes to greenhouses.
1. Perspex weighs less than glass.
A sheet of perspex is lighter than a sheet of glass. This makes it easier to transport and move materials whilst you are building your greenhouse, but it also makes your final result easier to use. For example, if you have a cold frame with a panel that you can slide open to access your plants, a light sheet of perspex makes the door lighter and easier to open. In contrast, if it were made of glass, it would be heavier.
2. Perspex is stronger than glass.
In spite of being lighter, perspex is stronger than glass. If falling fruit, lost birds or other threats hit your greenhouse, they are more likely to cause damage if it is made of glass than perspex. While glass may crack or shatter, perspex has enough flexibility to withstand the blows.
3. Perspex is easier and cheaper to modify.
Perspex, or acrylic, is also easier to modify than glass. If you need to add a few ventilation holes to the perspex on your greenhouse, you can drill in those holes without worrying about cracking or chipping the perspex. Alternatively, if you pay someone to modify your perspex sheets so that they fit more easily into your greenhouse, that is typically cheaper than paying someone to cut or modify glass for you.
4. Perspex has great insulating properties.
With a greenhouse, you need to use a material that allows light in, but at the same time, you need that material to insulate your greenhouse. A twin wall of acrylic has a R-value of 1.82. This is almost double the R-value of a single pane of glass, which is only .95, and it is almost the same as the R-value of a double pane of glass which is 2.0.
However, keep in mind that perspex is lighter and typically less expensive than glass. As a result, in terms of weight and cost, it makes more sense to compare a twin sheet of perspex or acrylic with a single sheet of glass than with a double pane.
If you want to learn more about how perspex compares to glass for greenhouses or any other applications, contact a perspex expert.