How to Insulate your Greenhouse  -  

It’s a great idea to line the inside of your greenhouse during the winter – it makes economical sense, is quick and easy to install. Frost-proofing the greenhouse will also mean you can extend your growing season for up to 6 weeks.

Working out how much bubble insulation you need and just how to fit it can be a problem, so the chart below will give a rough guide to what you will need.

Size of Greenhouse (feet) Amount of Bubble Wrap Required

6 x 4 14m (2 rolls, 1.5m wide)

6 x 8 18m (2 rolls, 1.5m wide)

8 x 10 21m (3 rolls, 1.5m wide)

8 x 12 27m (3 rolls, 1.5m wide)

Don’t forget to allow 3 alliplugs  and allispacers  per glazing bar and likewise with the corner adaptors

When fitting the insulation, the following information may help. 

  • Measure from the floor to the apex of the greenhouse up one side and back down other, and cut the insulation to length.
  • Go to the back of the greenhouse, away from the door then fold the insulation in half and secure the middle to the top ridge.
  • Work along each glazing bar securing the insulation to the roof and sides with the alliplugs.
  • Have a sharp knife handy to cut the bubble wrap where the vents and windows are sited. Repeat for the next panel, gradually working towards the door.
  • The end panel which includes the door is best tackled by attaching the insulation to the outside of the structure, cutting to size and then securing inside.
  • Simply cut the insulation which covers the door as this will allow both access and the bubble wrap to hang down – it’s a good tip to allow extra bubble wrap below the door which you can fold and weigh down, allowing less cold air to enter.