How to Choose the Best Bubble Wrap for Greenhouse Insulation
Insulating your greenhouse makes it possible to look after plants when the temperatures drop.
Not only can this help extend the growing season of plants, it can also preserve them over winter.
There’s a little more to it than simply hanging a few sheets of plastic in strategic places, so take a look at the information below to find out how to choose the best bubble wrap for greenhouse insulation (and how to install it!).
Bubble Wrap for Insulation vs. Standard Bubble Wrap
If you’re in the market for bubble wrap insulation for your greenhouse, you might be wondering if you can pop down to your local stationary store and grab a roll from there.
The answer is yes and no.
Whilst standard bubble wrap (the type used for protecting parcels) will have some insulative properties, it’s unlikely to be as effective as bubble wrap that has been designed for insulation. But why is this the case?
Starting with the positives, any type of bubble wrap consists of air trapped inside little plastic bubbles. This air heats up and can’t go anywhere, which in turn warms up the nearby air particles in the greenhouse. Sheets of plastic bubble wrap will also stop cold air from creeping in through cracks.
However, those are just the basic, and bubble wrap that is intended for greenhouse insulation often has additional useful properties. It tends to be stronger than standard bubble wrap, making it easier to put up and less prone to popping, and can have larger bubbles, which let more light in.
Additionally, the more premium bubble wraps for greenhouse insulation will be UV resistant. This makes them durable and able to be used year after year – something that is especially useful after you’ve gone to the effort of cutting the sheets to size.
How Much Insulation to Buy
Working out how much insulation is required at a glance isn’t easy. Fortunately, there are some estimated frameworks that you can use to decide roughly how much bubble wrap insulation to buy.
Remember that you will need to overlap the insulation in order to ensure there are no gaps. However, you need to be mindful not to overlap too much, or you may end up with insufficient insulation to cover the whole greenhouse.
A roll of insulation of 30 x 0.75 m should be sufficient to cover a standard greenhouse of 2.4 x 1.8 m (8 x 6 ft). With less overlap, it may also be possible to use the same amount for a 3 x 2.4 m (10 x 8 ft) greenhouse.
Bubble Wrap Thickness
Bubble wrap for greenhouse insulation comes in a range of thicknesses; the products you find will generally range from 4 – 15 mm thick.
As you can imagine, there are pros and cons to using either thin or thick bubble wrap for insulation, so that’s what we’re going to look at here in more detail.
If the bubble wrap is on the thinner side, around 4 mm thick, this generally means it will have small bubbles. It will be similar in appearance to bubble wrap used for packaging (in fact, it may even be exactly the same as parcel packaging!). Thicker bubble wrap will have larger bubbles; the bubbles will be more bulbous, resulting in thicker sheets of insulation.
Larger bubbles mean more light can get in. Even though we tend to think of all bubble wrap as being transparent, it actually has the potential to block quite a bit of light. This is particularly true when there are smaller bubbles because there are more structural veins present.
Thicker bubble wrap can also be easier to manage as it holds its shape better. Cutting accurate panel sizes may be more straightforward if the bubble wrap is more rigid. However, the downside of thicker insulation is that it will be more expensive.
Installing Bubble Wrap Insulation
When installing bubble wrap insulation, it’s one of those jobs that takes more time to prepare for than actually do – but the planning is crucial!
First off, you’ll want to make sure that you have enough bubble wrap to cover the whole greenhouse, allowing for approximately X of overlap on each side of each panel.
You’ll also need fixtures to attach the bubble wrap to the frame of the greenhouse. One of the easiest options is to use ‘alliplugs’. These pierce through the bubble wrap, and slot into grooves on the frame, holding the insulation in place. Of course, you could use insulative tape, drawing pins, etc., but you will risk either marking the glass, or tearing the bubble wrap (especially when you come to remove it).
Some bubble wrap insulation come with alliplug clips supplied; however, you may wish to buy more to be sure that you’ll have enough and won’t have to stop mid-job.
To cut the bubble wrap to the correct size, accurately measure each pane in the greenhouse. Then add on approximately 3 – 5 cm to each side, to make sure the pieces will sufficiently overlap to leave no gaps. Once cut, it is simply a case of securing the panels in place with the clips. This can be a lot easier with a second pair of hands to help.
You may need to remove plants and shelves from the greenhouse if you are not able to access the panes of glass with them in situ.
Bubble Wrap Insulation FAQs
Can I just use standard bubble wrap to insulate my greenhouse?
You can, but it won’t be as effective or long lasting as using horticultural bubble insulation. Standard bubble wrap is quite thin. It may tear easily when putting it up, and the bubbles may puncture. If the bubbles deflate, it will lose its insulative properties.
Bubble wrap that has been intended for insulation purposes may have larger bubbles to let more light in, as well as UV resistance. UV resistance will help stop the insulation from degrading over time.
What can I use to fix bubble wrap insulation to my greenhouse?
If your greenhouse has a metal frame, you can use alliplugs to attach the insulation to the greenhouse. These plugs fit into the grooves on the framework of the greenhouse and make installing insulation very easy. Even if you use alliplugs, you may have to use tape in some areas. Tape is a good option for connecting some of the panels of insulation together when necessary. If you have a wooden greenhouse, you can use drawing pins to attach the bubble wrap to the frame.
