Construction is just one of the many industries that use polythene – but nevertheless, it has become one of the most vital materials used by tradespeople, site managers and at all stages of the construction logistic process.
Polythene sheet is used in construction as a permanent building material, and as a temporary protective barrier. But of course, polythene is also used as packaging and pallet covers for the building materials in storage, on site, and in transit.
Here’s the how – and the why – behind the use of polythene sheeting in building projects around the world.
The uses of polythene sheet in construction
Polythene might not seem the most obvious choice as a construction material. But the things that make it so good at packaging – like its resistance to moisture, insulating properties, flexibility and light weight – also make it useful in other applications.
Protect concrete during curing
When concrete is poured for slabs, paths or for structurally important elements, it needs to be covered until it cures. The most obvious reason to cover concrete while it sets is to protect it from getting debris stuck in it – but it serves a deeper purpose than that.
Temperature and moisture have a profound effect on concrete as it cures, and if it cures too quickly, it can crack. That’s not only unsightly, it can be structurally dangerous.
Polythene is moisture-proof and an excellent insulator. By covering concrete with it, the water content can react with the binding agents fully before it dries off. This allows for a slower, more controlled cure with lowered risk of cracking.
The colour of the polythene is also important. Light colours reflect sunlight, and darker ones absorb it. That’s why, in hot and arid conditions, heavy duty white coloured polythene sheeting is used. In low temperatures, black coloured polythene sheet is used to absorb more heat.
But care has to be taken when covering concrete with coloured polythene, because it can transfer colour to the concrete. Clear polythene sheeting can be used as an underlayer, and in temperate conditions, can be used by itself.
Damp-proof membranes
Under-slab damp-proofing protects a structure from moisture coming up through the concrete. It’s extremely important, protecting against mould and damage to the building.
A heavy duty, single wound polythene sheet (of around 250 microns or thicker) offers excellent moisture protection and coverage. This makes it particularly useful as a liner and damp-proofing membrane.
High quality polythene sheeting made from virgin material is used for permanent installations like this, because the mechanical properties of polythene can be altered by the recycling process. Special polythene additives can also be used to enhance the natural water resistance of polythene, helping it hold up against prolonged contact with soil, water and concrete.
Recycled material can be used in less critical applications – like temporary coverings and protective uses.
A temporary weatherproofing material and dust cover
Polythene sheeting can be used as a dust cover, to protect floors while painting, or to protect large, immovable pieces of furniture while works are carried out. But it can also be used to seal buildings temporarily, as they are built.
While doors, windows, skylights or roofing elements are awaiting full installation, polythene sheeting can be used to create a temporary seal from light winds and rain. This is especially useful if delays occur on site and works have to be paused while parts and materials come in.
Packaging, transport and logistics
Due to the size and quantities of building materials required for a project, finding effective packaging solutions can be difficult – but large sections of polythene sheeting can be used to create effective coverings for construction materials at all stages of their lifecycle.
During construction, materials often need to be stored on site, where they’ll be exposed to the elements. To keep them safe from rain and dirt, polythene sheet makes an excellent covering – adding a UVI polythene additive helps to keep light-sensitive products safe when stored in direct sunlight, too.
Polythene sheet can also be used to securely transport goods on pallets, while offering the same protection against moisture, dirt and sunlight from the warehouse to the construction site.
Polythene sheet – the material with a million uses
Talk to our friendly polythene experts at NPF Packaging – and start your order for a custom blended polythene sheet. We’ll deliver your polythene sheet in any colour, and with specialist additives that meet your exact needs. Get a quote now, or call us on 01773 820415.
