Renovation Above-Rafter Insulation for Roofs
DuPont™ Tyvek® and AirGuard® can help you get the most out of renovation above-rafter insulation by protecting it from moisture and uncontrolled air leakage.
Renovation above-rafter insulation is often the preferred option when renovating roofs from the outside or repairing structural damage – especially when construction conditions do not permit renovation from within. To avoid heat loss and moisture damage, it pays to install an airtight roof membrane such as DuPont™ Tyvek® or DuPont™ AirGuard® between the rafters and the above-rafter insulation. This will improve the insulation properties of the building envelope and provide proven, durable protection. Depending on the building structure and the insulation material, either a vapour-open (DuPont™ Tyvek®) or vapour-closed (DuPont™ AirGuard®) membrane should be used.
DuPont™ Tyvek® and DuPont™ AirGuard® membranes are specially designed to minimise condensation and convective heat loss. They reduce heat loss in winter and increase thermal comfort in summer – all without intruding on living space. They can also help to provide additional R-value that can be added to the building structure.
DuPont™ Tyvek® and DuPont™ AirGuard® are fit for use as an windtightness layer in above-rafter insulation systems. They can be installed from the exterior without any problems.
Our recently developed AirGuard® Smart membranes go even further. These moisture adaptive (‘variable Sd’) membranes adjust their water vapour permeability automatically as humidity levels change.
The vapour resistance of DuPont™ AirGuard® Smart lies between 0.26MNs/g and more than 150 MNs/g, (Sd value 0.05m – more than 30m). In dry building structures, DuPont™ AirGuard® Smart acts as a traditional air and vapour control layer (AVCL), providing effective condensation control and airtightness. Even in temporarily high air humidity zones, water vapour diffusion is reduced and excess moisture in the envelope can dry out, both to the inside and outside.
DUPONT PRODUCTS & SERVICES
Tyvek® Supro is the market-leading breather membrane, and is a water resistant membrane suitable for all supported and unsupported pitched roof applications in commercial and residential buildings.
All Tyvek® breather membrane products
A complete listing of all Tyvek® breather membrane products
- Tyvek® AirGuard® Smart
DuPont™ AirGuard® Reflective is a low emissivity internal vapour barrier that combined with an airgap can enhance thermal comfort by reflecting up to 95% of radiant heat back into the building.
AirGuard® Reflective E
AVCL which boosts your thermal efficiency
DuPont™ AirGuard® Control is a tough, transparent vapour control barrier that improves airtightness by reducing convective heat loss and air leakage while also minimising the risk of condensation in roof and wall insulation.
- Discover the extended Tyvek® and AirGuard® airtightness solutions
Webinar: Design Air-tight, Condensation Free Buildings
With the trend towards greater energy efficiency in buildings, as driven by Building Regulations, air tightness plays a vital role in meeting these standards. While in the past little or no attention was paid to airtightness, in recent years it has come become clear how much air tightness can contribute to the energy balance of a building.
- Tyvek® Breather Membrane Solutions
- Tyvek® Sealing Tape
- AirGuard®: Vapour Control Layer Solutions
Tyvek® Supro at the Jamaica Inn: Reliable resistance for a windswept cultural icon
The famous Jamaica Inn is situated 280metres above sea level on Bodmin moor. The roof of its new accommodation extension benefits from advanced breather membrane Tyvek® Supro, which is fully compliant with BS5534:2014
INFORMATION & IDEAS
- How to - Selecting the right vapour control and vapour barrier sealing tape for the job
- How to – Vapour control and vapour barrier installation
- What Makes a Tyvek® Watertight Breather Membrane Unique?
Underlayment: Quality and Thickness of Functional Layers Are Critical
Tyvek® membranes are proven to resist ageing better than most common multi-layer underlayments. Even after prolonged exposure to UV radiation and heat, Tyvek® underlayment stays watertight and provides superior condensation control.
- The Tyvek® Evolution Story
- Building In Energy Efficiency
- How to - Fixing the vapour barrier and vapour control membrane – timber, concrete and steelwork
- How to - Install vapour control and vapour barrier membrane on down lights and ceiling hatches
CE Compliant Membranes
All DuPont breather membranes, including Tyvek® and AirGuard®, are fully CE compliant, and carry the CE marking required throughout Europe.
- Free CPD Seminars
- Tyvek® is compliant to New BS5534 Annex A
- Tyvek® offers unrestricted application when tested in accordance with BS5534:2014