Bubble Foil Insulation Under Concrete

(Link to the full pdf magazine article to be found at the bottom of this page)

A new study on underslab insulation conducted by the Canadian Mortgage and Housing Corporation (CMHC) has confirmed what a lot of people in the hydronic heating industry have suspected.

?The floor we tested with bubble foil underneath did not look like it had any insulation underneath,? reported Don Fugler, senior researcher in the CMHC policy and research division.

In fact the report left no doubt about how bubble foil performed:
Bubble-pack insulation showed performance that was similar in nature to an uninsulated floor. There was little temperature difference between the inside of the basement and the ground below, the ground temperature varied with indoor temperature, and the ground under the insulation was warmer than expected for undisturbed deep ground temperatures,' said the report.

Fugler noted that he has seen manufacturer's claims of as high as R-15 for bubblepack. The message, he added, is that the contractor should not accept a manufacturer's claims if they cannot provide independent verification for their test results.

As for bubble foil as an underslab insulation: ?If you want to use it instead of six mil poly, that's okay,? he laughed.

CMHC Comparison of Under-Floor Insulation Systems

it's cost benefit was the poorest of all insulating materials tested.

A cost-benefit analysis suggests it is a better option than the bubble-pack insulation.