125mu (500G) Green Vapour Barrier 4m x 50m (200m2/Roll)

Green Vapour Barrier, as its name would suggest, serve as a 'barrier' against moisture, inhibiting the passage of water vapour between the outside and inside of a building structure. 

When insulating a property internally, a vapour barrier is an absolute necessity; the only exception to this is if your insulation already boasts a vapour-resistant layer. Vapour barriers are usually installed in conjunction with insulation to ensure a successful building enclosure. 

125mu (500G) Green Vapour Barrier Applications

Unlike breather membranes (which are installed on the cold side of insulation) vapour barriers are typically installed on the warm side of your insulation. Placing a vapour barrier on the warm side of your insulation reduces the risk of condensation forming because it stops warm, moist air from coming into direct contact with a cold surface inside your wall.

It should be noted that waterproofing membranes are significantly more effective at waterproofing than vapour barriers in the majority of weather conditions.

We recommend Green Vapour Barrier in the following applications: 

• Under floors
• Within walls
• Roof applications
• Timber frame structures
  
  

125mu (500G) Green Vapour Barrier Specifications 

• Prevents interstitial condensation within the building structure
• Restricts the passage of warm, moist air within the building
• Vapour resistance of 266 MNs/g
• Helps to prevent mould and damp staining
  
  

How A Vapour Barrier Works

The most common type of vapour barrier membrane is a sheet of plastic (polythene) or foil that is installed on the warm side of the structure, typically on the interior of the walls. A vapour barrier is effective at preventing moisture from entering the structure whilst trapping moisture that is already present, which can lead to condensation and mould growth. 

Why A Vapour Barrier Is Essential

A vapour barrier is a crucial element in any building construction as water vapour is an inevitability in any building. We produce it when we do our laundry, when we cook our tea and even when we breathe. 
However when condensation forms, its inevitable presence can degrade the efficiency of insulation material and its ability to prevent heat transfer, causing interstitial condensation, mould and damage to the building fabric. 

Vapour Barriers VS Vapour Control Layers 

Vapour control layers are designed to 'control' and slow moisture penetration, as opposed to blocking it completely. A vapour control layer (otherwise known as a vapour retarder) is airtight in its design and because of this is typically employed in areas where airtightness is a concern. 
When utilised in a roof space, VCL is usually employed alongside a breather membrane to stimulate air flow. 

Vapour barriers, on the other hand, serve as a 'barrier' that fully obstructs the movement of vapour and air.