Tyvek® proven to outperform cheaper products in a complex market

5 Sep 2018

Tyvek® has been proven to provide lasting performance and peace of mind, where cheaper membranes fail.

This comes after the revelatory results in the 2016 tests for watertightness in ‘real life’ roofs, which were followed by a further 20% of roofs being opened with their membranes tested under the same strict, independent criteria.

The percentages speak for themselves: 94% of roofs over 20 years old fitted with Tyvek® pass with flying colours.

These stats are more impressive when you consider that roofs less than 10 years old fitted with other underlays saw only 21% remain watertight, demonstrating why Tyvek® is such a highly trusted product.

Concerned by multiple reports of some alternative vapour-open underlays failing in their secondary water shedding role, Tyvek® instigated a thorough investigation into ‘real world’ performance two years ago.

These reports put the reputation of a whole class of roofing underlays at risk, and as industry codes have yet to catch up, it was right that the market leader stepped up to investigate the issue.

Qualities such as long term water hold out – which most crucially affects the homeowner – can only be effectively assessed after exposure to natural environmental stresses, both during the build and when occupied.

While ageing of underlays can positively affect vapour diffusion with increased porosity, this may adversely affect the water shedding function, should the primary covering fail.

This unfortunate occurrence is becoming more prevalent in today’s increasingly stormier weather. Ultimately, the primary quality in terms of membrane longevity is watertightness – an area which presents the most risk for property, insurance, and reputations.

All membrane samples were taken from the roofs and the tests were performed by an independent expert, using the EN13859-1&2 W1 classification system for watertightness.

Each specimen was exposed to a 20cm water column for two hours to measure not only whether any leakage occurred, but how much, over what surface area and how quickly.

This established, in crucial and revealing detail, precisely how well each underlay withstood water after 5 to 10 years in a roof, or, in the case of Tyvek®, for more than 20 years.

The following link features an updated page on these ageing tests, which includes a short video and a summary of the findings http://tyvek.construction.dupont.com/rooftest

DuPont Protection Solutions
BBSP1
Bristol & Bath Science Park
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Emersons Green
Bristol
BS16 7FR

Phone: 08444 068 722

Technical enquiries: [email protected]

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