House & garden

Which multi-skin sheets for greenhouses and cold frames? Tips for selection and assembly

Durable and practical – this is how polycarbonate greenhouses can be described. In terms of performance, they outperform similar systems made of film and glass. However, so that this modern material can show its best properties, it is important to know what to look for when choosing multi-skin sheets for the greenhouse or cold frame and how to assemble them correctly.

The advantages of polycarbonate sheets

Greenhouse made of polycarbonate sheets for tomatoes

Why should you use multi-skin sheets made of polycarbonate for your greenhouse or cold frame? The answer is: Because the material has many positive properties and offers a lot of advantages, such as:

  • excellent thermal insulation
  • high light transmission
  • reliable protection against UV radiation
  • high strength, impact strength, rigidity and hardness (compared to glass, the strength of polycarbonate is 50 times higher, the impact strength 250 times higher)
  • easy installation
  • long durability
  • Resistance to high humidity and various atmospheric influences
  • high aesthetics: you have to admit that a polycarbonate greenhouse (or cold frame) looks very beautiful, stylish and natural in any garden, and can also blend in perfectly with modern landscaping.

7 tips for selecting and installing multi-skin sheets for greenhouses and cold frames

Multi-skin sheets for greenhouses and cold frames, clear, tinted or opal

Regardless of whether you buy a greenhouse or cold frame made of polycarbonate or want to build it yourself, the instructions for installing the multi-skin sheets hardly differ. The following special features must be observed here:

Multi-skin sheets for greenhouses – clear or opal?

Greenhouse-made-of-multi-skin sheets-for-growing-young-plants.

Only transparent polycarbonate should be used for a greenhouse or cold frame. Tinted double wall sheets look more attractive, of course, but they let in much less light and your plants won’t get enough sun. And that is crucial for a good harvest.

UV resistance is particularly important

When choosing multi-skin sheets for the greenhouse or cold frame, make sure that they have a special UV protective layer on at least one side. When installing, lay the panels so that the protective layer is on the outside.

Which plate thickness is best?

Greenhouse for growing tomatoes

The thickness of the polycarbonate sheets depends on how exactly you intend to use your greenhouse. This means that if you only want to use your greenhouse in spring and autumn (unheated) for growing young plants, a panel thickness of 5 to 10 mm is completely sufficient. Even 6 mm double wall sheets for the cold frame are an optimal solution. If a greenhouse is to be heated, the thickness of the polycarbonate sheets should not be less than 15 mm.

Pay attention to the laying direction of the multi-skin sheets

All double wall sheets have hollow chambers that run parallel to the sheet length. During assembly, the multi-skin sheets should always be laid with the chambers in the direction of the water flow and not across.

Mount multi-skin sheets correctly

Fasten multi-wall sheets with screws and washers

Polycarbonate sheets should be installed with special installation profiles made of aluminum or plastic. Self-tapping screws made of stainless steel are used to fasten the multi-skin sheets. A rubber washer should be installed underneath.

Since the polycarbonate has a high coefficient of thermal expansion the hole must be slightly larger in diameter than the screw. Fastening should start from the edge of the plate at a distance of approx. 5 cm, the distance between the fastening points should not exceed 30 cm.

Never nail the multi-skin sheets in place – this will compromise the integrity of the sheet and inevitably lead to its destruction. Also take into account that the panels cannot overlap.

Don’t miss out on important details

Cold frames made of wood and multi-wall sheets for salads

Do not save on components that are necessary for a professional assembly of the multi-skin sheets! Such seemingly insignificant details such as adhesive tapes, end profiles and seals significantly extend the life of your greenhouse and prevent irreversible contamination from dust, algae and insects.

The cheap is expensive

Given the variety of polycarbonate sheets available on the market, special attention should be paid to quality. In many cases, the price is perceived as an indication of the quality, so it is best to use medium-priced or more expensive multi-skin sheets – they will last much longer.

The multi-skin sheets are also very popular as patio roofs. You can learn more about this in this article.

10 mm multi-skin sheets ideal for unheated garden sheds for growing vegetables