Replies

1. GBA Editor
   Brian Pontolilo | Nov 25, 2019 09:42am | #1

   Hi Newmedia.

   First, many homes have high TVOC levels. Replacing every material releasing VOCs is one solution (though it is nearly impossible), proper ventilation is a more reasonable solution. This article addresses ventilation and human health: Ventilation Rates and Human Health

   If you are exhausting stale indoor air and providing adequate fresh air with a Balanced Ventilation System and you still have high levels of TVOCs, and you choose to remove the spray foam, you have lots of options.

   First read this (How to Build an Insulated Cathedral Ceiling) to understand the possible assemblies for an insulated roof. Then, read this for resources for more healthy materials: Indoor Air Quality and VOCs

2. Expert Member
   Michael Maines | Nov 25, 2019 07:08pm | #2

   Newmedia,
   Removing spray foam is a major undertaking--one of many reasons I don't like using it, along with other reasons such as the potential for a flawed installation and its significant contribution to global warming. If you do remove it, there are many types of insulation that could replace it, but they need to be vented. Will your roof design allow for at least 1" (1.5" or 2" is better) directly below the sheathing, with continuous vents at the soffit and ridge? If not, the only other option is to cut-and-cobble rigid foam into the space, but that's an approach that is hard to do properly.

3. 
   newmedia | Nov 25, 2019 08:04pm | #3

   Thank you so much Brian and Michael! I think the SPF installer will remove the foam for me.
   The reason why I'm trying to remove the SPF is that TVOC level was 2500 ng/L during the summer time. My family had respiratory problems.

   The third floor is right under the roof. It's a roof/bed room. (I hope you understand what I'm saying.) The roof does not have soffit and ridge currently. (There is no venting structure.) The room is inside the roof. I am currently venting to the side of house. I hired a contractor to make penetrations on the external walls.

   So it seems every insulating materials are stinky. Is it true? Which one is less harmful?

   Thank you!

1. Expert Member
   Michael Maines | Nov 25, 2019 08:23pm | #4

   Newmedia, you should read this article: https://www.greenbuildingadvisor.com/article/how-to-build-an-insulated-cathedral-ceiling. Most insulation is NOT "stinky." My go-to is cellulose, because it has very low embodied carbon, insulates well, is not toxic to humans (it typically has natural mineral borates that are fire and insect retardant) and it handles moisture well. But fiberglass (batts or blown) and mineral wool (Rockwool, formerly Roxul, is the best-known brand) are also essentially zero VOC these days.

1. 
   newmedia | Nov 25, 2019 08:45pm | #6

   Yes. Brian also recommended that one. I will read it. Thank you!

2. Expert Member
   BILL WICHERS | Nov 25, 2019 08:34pm | #5

   Before you try removing that spray foam, are you SURE it is the problem? SPF often takes the blame, but isn’t always the problem.

   If the SPF IS the problem, maybe you can air seal the sealing and encapsulate it to avoid having to remove it. Encapsulation might be easier and faster/cheaper than actual removal of the spray foam itself.

   Note that other insulating materials can’t always be used as substitutes for spray foam so if you do choose to remove the spray foam, be sure you don’t replace it with something that will end up causing you some kind of new problem (moisture, mold, etc).

   Bill

1. 
   newmedia | Nov 25, 2019 08:46pm | #7

   Bill. That's also good idea. Where can i find more information about the air seal?

   Thank you!
   Jin