More warnings about using foil or bubble products in contact with concrete.

  NHBC Guidance on Multi Foil Insulation, 2006  "The NHBC has recently published guidance regarding multi-foil insulation performance in its Standards Extra, to the effect that multi-foils will not be accepted under its warranty arrangements until a consensus on the performance and testing of these materials is achieved."
TIMSA welcomes clarification of insulation regulations, 2006  "This guidance resolves a growing problem whereby claims for thermal resistance of multi-foil materials based on arbitrary testing indicated much higher values than have been obtained when these materials are subjected to proven, relevant standard test procedures - sometimes by a factor of five...over recent years many buildings have been completed with foil materials not certified by accredited bodies which may not even satisfy the standards required by Part L: 2002, putting seriously at risk the Government's stated intention to raise buildings' energy performance standards..."
Energy Design Update , September 2006  "...the statement is kind of deceptive, because it gives the impression that if you use this product (reflective insulation), you will cut the heat flow through the wall by two-thirds, and that clearly isn't true."
State of Nebraska, 2009 "Although the p2000 marketing materials do provide reference to some ASTM tests being completed -
the completed tests are not the appropriate tests required under the R-values regulations of the Federal Trade Commission regulations."
  Autodesk Ecotect, 2009  "...foil by itself does not provide thermal resistance; foil facing an air space increases the resistance of the air space. The increase in resistance achieved by subdividing will be reduced if any air is allowed to move from one space to another or if the reflective surface becomes coated with dirt or condensation."
This is an excerpt from an advisory from Natural Resources Canada, Released May 2007:
"As a result of countless inquiries from the general public, building contractors and building professionals concerning claims made by manufacturers of foil-faced bubble insulation (FFBI) products, Natural Resources Canada (NRCan) has prepared this paper dealing with the effective thermal resistance (RSI/R value) of these and other reflective types of products for the purpose of energy modeling under its energy efficiency housing initiatives."
  Radiant Panel Association Newsletter, 2007  "Reflective foil under a slab, with no airspace, is totally ineffective as an insulator. Reflective foil with a bubble or foam core is only slightly more effective than the bubble or foam by itself."
  The UK Mineral Wool Association, 2007  "In recent months the government has moved to give guidance on the use of multi-foil insulation...It has written to all local building control departments and to bodies such as the NHBC...(advising) they could no longer accept the thermal values claimed for (brand x) and similar products"
Sustainability Magazine, 2007  "The architects who specify such products and the building engineers who sign off houses insulated with them may be leaving themselves open to litigation from clients who will understandably be very angry that their new home is not insulated to the required standard."
  Northwest Energy Efficiency Alliance and Washington State University Extension Energy Program,         Product & Technology Reviews, 2007  "We conclude that an under-slab installation is not a good application for this type of product (bubble foil), even if only used to replace a vapor retarder."
  Reflective Insulation Manufacturers Association, 2008  "Claims of high R-values for reflective products when they are used as under concrete insulation are not supported by any industry or code body accepted testing methods. Products installed under concrete slabs cannot reflect heat because there are no air spaces present."