Greenhouse glass panels have been in use for centuries, from the very beginning of greenhouse history.
Until fairly recently (mid-1900’s), glass greenhouse panels were the only type of greenhouse coverings available.
But a glass greenhouse is far from just an antique throwback.
Because even though glass would have been used in the very first greenhouse, and even though glass was the only greenhouse glazing available for centuries – in some ways, it’s still one of the best forms of glazing.
The most obvious advantage of greenhouse glass is its appearance.
Few would argue that a greenhouse glazing of poly plastic, for example, looks better than glass. And even though a glazing such as polycarbonate can sort of mimic the look of glass, it’s just not quite the same.
For some greenhouse gardeners, the appearance of the greenhouse is quite important. But others are strictly concerned about the functionality. And glass is no slouch in that area, either.
Glass offers greater light transmission than any other of the most commonly used glazings. Insulated glass offers about the same insulating value as double-layer, air-inflated poly plastic.
And by any measure, glass offers a far longer service life than any other type of greenhouse glazing material. A glass greenhouse can potentially offer decades of service. No other glazing material can match glass in terms of potential service life.
As mentioned above, greenhouse glass will provide a longer service life than any other form of greenhouse glazing. That is, unless - CRASH-SHATTER-TINKLE! Well, you know …unless that happens.
And of course, ‘that’ is far more likely to happen with glass than with any other type of greenhouse glazing material. Which brings us to another principal disadvantage of glass – cost.
Glass is far more expensive than all other types of greenhouse glazing. So when you’re building your greenhouse, or when ‘that’ happens and you have to replace the glass, your bank account is going to be more bumped and bruised than if you were using a different type of greenhouse covering.
To be fair about it, though, over the very long term, glass might not really be all that much more expensive.
After all, there’s a potential to get decades of service out of greenhouse glass. And the odds are against something happening that wipes out ALL of the glass panels of your greenhouse.
It’s more likely that you’ll have the occasional broken panel from a rogue baseball or freakishly large hailstone. (There's no need to belabor the point that people who live in extremely hail-prone areas shouldn’t tempt fate by having glass greenhouses!)
So over the course of 30 years, if you have to replace just a portion of the glass panels due to occasional minor mishaps, you might actually come out ahead in terms of cost. Because you would have had to completely replace - multiple times - whatever other form of glazing you might have used during that time period.
And the glass that is used in modern greenhouses is usually tempered and thick enough to be less susceptible to breakage than you might think. Still though, glass is undeniably more prone to breakage than any other type of greenhouse glazing.
Glass also comes with the disadvantage of being heavier and more difficult to handle. And just like polycarbonate, installing glass is labor-intensive because it must be set panel-by-panel onto a greenhouse framework designed to accommodate the glass panels.
…Are likely to have the prettiest greenhouse in the neighborhood.
With luck, they’ll enjoy decades of service from their glass greenhouse. The inner beauty of their greenhouse will be apparent to anyone who’s lucky enough to get a glimpse of their greenhouse from the outside. Their happy greenhouse plants will enjoy more precious sunlight than the plants in any other type of greenhouse.
And they really shouldn’t throw stones!