Vapour Control Layer

Have you been instructed to have a vapour barrier installed on an existing roof or new flat roof?

A vapour control layer helps you protect your building from the consequences of condensation. Condensation is formed when warm moist air rises and condenses into a liquid on contact with the colder surfaces above the insulation. The idea behind a vapour control layer is to install it on the room side of the insulation so it blocks the passage of warm moist air entering the structure. We specialise in warm roof construction and have been working closely with building control to ensure our systems exceed that which is specified within the regulations.

Get in touch with us and we will respond promptly and can even attend the property the same day in an emergency, for example, severe water ingress.

Why do You Need a Vapour Control Layer on Warm Flat Roofs?

  • Minimises the amount of warm moist air that enters a construction element.
  • A VCL prevents damp and mould which in turn, prevents major respiratory problems.
  • The VCL works in conjunction with the ventilated cavity to minimise the risk of harmful condensation.
  • A vapour control layer will prevent installed insulation getting damp and losing it’s thermal properties.

Why Choose Us?

  • Over 30 Years Experience
  • Excellent Customer Service
  • Insurance Backed Guarantees
  • We Get it Done on Time
  • Flexible Systems & Pricing
  • Rated 5 out of 5 by Our Customers

Video Explanation of a Vapour Control Layer or VCL

In this video our principal estimator – Steven Dickinson demonstrates how a VCL is incorporated into a warm flat roof.

Vapour Control Layers in Warm Flat Roofs

We have thermal experts on staff to ensure our VPLs’ exceed the minimum requirements set out in the building regulations.

The buildup of a warm flat roof starts with a good vapour barrier followed by insulation then more decking or just the roofing materials depends on if you want the roof soft or solid. Just what vapour barrier to use is not that clear. Is the silver foil to the back of the insulation OK to use for the vapour barrier? Is a sheet of plastic OK?

The detailing of the warm roof is very important if gaps in the insulation are left cold bridging can occur and potentially sweating could happen.

Warm roof technology is still evolving so; please make sure your roofer understands what he is doing. We find that we get lots of phone calls from the public explaining that their roofer has installed a warm roof with ventilation which is incorrect.

The subject of vapour control layers can  be tricky to understand so pleas do feel free to get in touch if you need any more advice.