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Community and Q&A

Should I get spray foam insulation applied to the outside of my flat roof?

VfvZrCQQNh | Posted in GBA Pro Help on

A spray foam insulation company recommended that I have spray foam insulation applied to the outside of my roof (which is totally flat) and then coat that with a reflective material. (I can’t have it sprayed in my attic because I don’t really have an attic, just a 2-3 foot crawl space.) However, a roofer said that he would not recommend doing that because it would cause trouble down the line if something happened to the roof, such as a tree falling on it. I have no idea what I should do. Advice?

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  1. GBA Editor
    Martin Holladay | | #1

    Closed-cell spray polyurethane foam has been used as roofing for many years. Here is an article I wrote on the topic: Roofing with Foam.

  2. user-1103036 | | #2

    Martin's article is very good, and contains all the major considerations with SPF roofs. SPF roofs work well (I have one I my building). Make sure you find a good contractor with specific experience with SPF roofs- it is a trade in itself. Where are you located?

    And a tree on your roof will cause trouble no matter what kind of roof you have. The foam might actually help hold it together if a tree falls on it.

  3. wjrobinson | | #3

    Agree, you need the correct spray crew.

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