Glass or Plastic Panes for Your Greenhouse?

A greenhouse is a great way to grow flowers and other plants all year round. If you are considering buying a greenhouse, you will probably know there are many different options when it comes to deciding what type of greenhouse to buy.

Once you have decided on the shape and size of your greenhouse, you then have you make the decision about whether to use plastic or glass panes. But even when you have decided which material to use, you’ll find there are further choices to make between the different types of glass and plastic.

Glass choices for greenhouses

Let’s begin with looking at glass panes for your greenhouse. The two main types of glass used for greenhouses are standard horticultural glass and toughened safety glass. Both are quite similar to one another, but each has its disadvantages and advantages which should be carefully considered before making a choice.

The main differences between the two types are strength and price. Standard horticultural glass is cheaper but weaker than toughened safety glass. While toughened safety glass is more expensive than standard horticultural glass it should end up lasting a lot longer, and it won’t scatter dangerous splinters of glass if it does break. But both are very clear and are generally considered to look better than plastic panes.

Choice of plastic panes

If you are considering using plastic there are also different types available for use on a greenhouse. These can be grouped into two categories, film plastic and rigid plastic. Film plastic, usually made of polyethylene, comes in a range of different thicknesses. The thicker the plastic the longer it is likely to last.

The main disadvantages with film plastic are that it is more prone to damage, has a shorter lifespan, and retains far less heat than glass and its rigid plastic counterparts. But on the upside it is cheaper than both.

Rigid plastic panes

Rigid plastic is more commonly used than film plastic, and polycarbonate is most often used for garden greenhouses. You may have come across greenhouses with polycarbonate safety glazing before, and from a distance they can look deceptively similar to a real glass greenhouse. But there are some important differences that are easily noticeable once you know them.

Polycarbonate safety glazing is made of two sheets of polycarbonate, which means it performs like double glazing and provides excellent insulation. The main advantage it has over glass is that it is lighter and shatter-proof.

The disadvantage is that dirt and algae can build up between the two sheets of polycarbonate over time, which is very hard to clean off. It is also simply not as clear as either standard horticultural glass or toughened safety glass.

Glass pros and cons

You need to weigh up the pros and cons between glass and plastic before you can decide. Glass is the traditional material used for greenhouses, and arguably works best. Standard horticultural glass is fine, but panes made of this type of glass do seem to inexplicably break on occasion. If you think it could be at risk of, or you have small children who may be hurt, go for toughened safety glass if you can afford the extra cost.

Plastic pros and cons

Polycarbonate safety glazing is a great alternative though, and should not be dismissed. It lets in pretty much the same amount of light as glass even though it is not quite as clear. One important advantage it does have over glass is that it is easy to dismantle and move to another location. So if are planning a move and want to take your greenhouse with you, consider plastic or wait until you’ve moved if you really want glass. Polyethylene film plastic is probably best avoided unless your greenhouse is only temporary and you are looking for the cheapest way to construct one.

Summarising – plastic versus glass panes

So when it comes to glass versus plastic for your greenhouse there are some important things to consider. Think logically and the decision can be made much easier. For instance, if you live in a busy neighbourhood, get the odd football flying over the garden fence, and often have small children playing in the garden, polycarbonate safety glazing is probably the way to go.

On the other hand, if you live in the quiet countryside, intend to keep your greenhouse for many years, and want it to have the best possible appearance, then standard horticultural glass could be your best option. If glass is a must and you have young children then you should certainly use toughened safety glass.