From an unfortunate situation arises a further demonstration of superior resistance

DuPont™ Tyvek® Reflex provides long term protection

August 2011 - In this period of uncertainty in the UK construction market, it is encouraging to know that some manufacturers (and their distributors) place significant emphasis on the durability and integrity of their products. DuPont Building Innovations, the division responsible for the renowned DuPont™ Tyvek® family of membranes is one such manufacturer. Not only does the company’s innovative approach consistently develop new solutions and systems for the benefit of the market, but the resulting product range offers long term performance and peace of mind.

This has been proven on a number of occasions, but perhaps few more dramatically than on one construction site towards the end of 2010. The product in question is DuPont™ Tyvek® Reflex, the original low emissivity breather membrane for walls, which was installed in four timber frame houses in Burwell.

The membrane was supplied by SIL Bedford to Kingspan Potton (a long term user of DuPont™ Tyvek® Reflex) and factory fitted to the timber frame panels during manufacture in March 2008. Unfortunately the main contractor went into administration during the build, leaving the work incomplete and subsequently the membrane was left fully exposed to the elements and potential UV degradation for a period of 33 months.

As unfortunate as this situation was, it nevertheless offered an opportunity for DuPont to test the product under such extreme conditions. Samples of the exposed material, which were removed for examination by DuPont at its facility in Luxembourg, provided the following results.

 

 

Property
 
Standard
 

Unit
 

3480M
 

North after
 

South after
 


 


 

 
 

nominal
at new
 

33
months UV
 

33
months UV
 

water
tightness
 

EN1928 with
 

Class
 

W1
 

W1
 

W1
 

Class
 

modifications
 

 
 

 
 

 
 

 
 


 

EN13859-2
 

 
 

 
 

 
 

 
 

water column
 
EN20811
 

m
 

> 2
 

2 / 2,2
 

1,6 / 1,8
 

Emissivity
 

Lux meth.
 

 
 

0,15
 

0,18
 

0,18
 

Tensile MD
 

EN 12311-1
 

N/5cm
 

250
 

215
 

212
 


 

mod. EN13859-2
 

 
 

 
 

 
 

 
 

Tensile XD
 

EN 12311-1
 

N/5cm
 

210
 

180
 

164
 


 

mod. EN13859-2
 

 
 

 
 

 
 

 
 

 


DuPont guarantees the functionality of DuPont™ Tyvek® Reflex on the basis that it is protected from UV exposure within 4 months of installation and tests have shown that the product will suffer no reduction in performance over this time. However, in this case, the recommended time period was clearly exceeded – and by over 800%!

These test results demonstrate that companies such as Kingspan Potton, when choosing a product with such proven reliability, can be confident in the long term performance of the membrane in terms of both energy efficiency and the protection of the structure, even when exposed to wind, rain and UV. The two most important criteria for a reflective breather membrane are

 

 

 

 

 

  • the emissivity value and hence the benefit to the structure’s u-value
  • protection against water ingression (304)


From the test results above, watertightness is unaffected, while the emissivity performance saw a drop of only 0.03. This is a significantly minimal reduction in performance, particularly when the considerable exposure time is taken into account and thus offers distributors, manufacturers, contractors and home owners the reassurance that when DuPont™ Tyvek® Reflex is installed to the manufacturer’s instructions, the enduring reliability of the product is guaranteed.

This example also illustrates how the product provides a structure with long term protection against all weather conditions. Over the preceding 33 months, the area of Burwell (and therefore the construction site in question) experienced the full range of UK climatic conditions without any damage being sustained by the membrane.

 

 

 

 

 

 

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