Is polypropylene floor padding toxic when used over heated floors?

Question from Wild4Nature

I am installing a bamboo floor over my hydronic (heated) floors. The flooring company uses FloorMuffler padding which contains polyethylene and polypropylene resins and carbonylamine of azo. Will these give off toxic fumes when heated (to approx. 72 degrees) by my underfloor heating system.

Debra’s Answer

Both polyethylene and polypropylene have relatively low toxicity as far as plastics go, however, heat will always increase the offgassing of soft plastics.

I don’t anticipate this would be a big problem. If it were me, however, I wouldn’t put anything that could outgas on a heated floor. I would only put ceramic or porcelain tile or stone on a heated floor. When these materials are heated, there is no outgassing, and they hold the heat. That’s just my level of precaution.

I’ve never had heated floors myself, but it seems to me to put a wood floor over them kind of defeats the purpose, as wouldn’t the wood not hold the heat well?

All that said, if the temperature is only 72 degrees, that’s basically room temperature, and I don’t see that the outgassing would be any greater than having these materials in any room.

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6 Comments

Tile Contractors Portland Oregon on November 16, 2020 at 6:15 am

There are actually a variety of thoughts to take into consideration. Thank you for your knowledge and ideas.

Karen on June 21, 2015 at 8:49 pm

Hi Debra
I was thinking about installing some Warm Window Insulated Shade Lining on the west side of my house which has our bedrooms. The materials include polyethylene, polypropylene and cotton. Will these “polys” out gas into our bedrooms?
Thanks!
Karen

Debra Lynn Dadd on June 22, 2015 at 3:18 pm

They shouldn’t. They are made from very tightly bonded molecules.
Reply
- Marilynn on June 23, 2015 at 5:38 pm
  
  It is my understanding that all polys off gas to some degree. Wood over hydronic floors is highly recommended – especially reclaimed wood.
  Reply
  - POp on November 29, 2017 at 12:58 pm
    
    Hi Debra,
    
    Thanx a lot about this answers.
    
    I have heated floors. And under my parquet I installed an aluminium foil 2mm thick (is a soft foil used to compensate the irregularities of the hard floor, special use for underfloor heating). Is that toxic, since aluminium is an toxic element? thank you for your answer
    Reply
    - Debra Lynn Dadd on December 4, 2017 at 10:22 am
      
      Not toxic because to the best of my knowledge aluminum wouldn’t vaporize at that temperature. Read more about volitization of metals.