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Spraying closed cell foam in a sealed basement of existing home – venting the fumes?

whitenack | Posted in Green Building Techniques on

Hey all,

We have a storm shelter in our basement (room off the basement, under the back porch) that has a condensation problem (shelter ceiling gets cold in winter, mixes with warmer air from rest of basement).  We are planning to solve that problem by spraying the condensing surface with closed cell foam.  There are no windows or openings in the basement, so venting the area during the job is not possible, other than setting up fans to blow the air up to the living space and then out a door/window.  The way the house is configured, there is a long pathway from the storm shelter to the nearest opening to the outside.

We will be doing this project while we are out of town, so the house will have several days to air out after the job is done.

What is the best way to handle this situation?  Is it best to just seal up the room for several days and let the chemicals dissipate, or will they still linger and cause problems?

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  1. Expert Member
    BILL WICHERS | | #1

    If you want the fumes to dissipate, you can’t just “seal up” the room — doing so would give the fumes nowhere to go. If there are no vents you can open to let the room breathe, you can rent ventilators and flexible ducting to blow air into the space from somewhere else. These types of portable ventilation systems are commonly used by utility crews while they’re working in manholes or other underground locations.


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