VIP’s, what are they and are they all the same?
ViP’s, or Vacuum Insulated Panels are a bit of an oddball in the insulation world. Unlike PIR or XPS insulation, they contain no blowing agent to create a cell structure to provide their insulation value. They also don’t contain air like Stone Wool insulation does. In fact, they contain nothing but silica sand. Not quite the stuff you find on a beach but very similar to the sand you may cast when installing liquid applied membranes.
The ‘vacuum’ part of the panel produces the ultra-high efficiency insulation performance. The sand is only there to hold the ‘vacuum’ into a shape that we can work with, typically a square or a rectangle. The silver foil that surrounds the sand is the clever bit, and as you would expect not all foils are the same, nor is the way the foils are sealed to hold the vacuum. These are the clever bits usually covered by a patent, one reason they are all different. Companies such as Va-Q-Tec AG in Germany have patented foils and sealing systems that date back to 2001, and they continue to invest in research and development to ensure they remain at the front of the market; including developing a B2, s1-d0 foil as part of the journey to achieve an A2, s1-d0 classification for external wall applications.
But there are limitations to ViP’s, not least of which is the cost; they are 3 to 5 times per m2 more expensive than a ‘normal’ insulation board. This disadvantage disappears when a ViP is the only solution to achieving a level threshold on an incorrectly installed deck – if your slab is 80mm too high the most cost-effective way to achieve the U-value and level threshold is often to use a ViP. The foil cannot be punctured, so methods of protection need to be employed, or the panels coated for protection. ViP’s cannot be cut, which is why schemes have to be designed for every individual roof.
Last month we focused on the ever-increasing demand from clients, building control, insurers, contractors and specifiers for accreditation. This is never more important than when using a product that there are no British or European Standards for, as is the case with ViP’s. That is why more and more suppliers and contractors are being asked for BBA certification to prove a product is 3rd party verified for the proposed application. Do a search for ‘Inverted Roof insulation’ on https://www.bbacerts.co.uk/search/ and you will find 7 no. certified EPS or XPS insulation boards, but only 2 no. for ViP’s. Change the search to ‘Roof Insulation’ and you get 18 certificates, with the same 2 ViP’s. Widen that search to just ‘insulation’ and you get 211 certificates. Can you guess how many are ViP certificates? Oh yes you can! Next time you are using a ViP remember only 2 currently have BBA Certification and they are only for inverted roof applications, so using others may be at your compliance risk.
Next month’s QI by QI – ‘Insulation developments in 2021, a retrospective.’