Why do we perform insulation extraction?
When we talk to clients about insulation extraction (removal and disposal), the initial reaction is “why?!” Most people think more is always better when it comes to insulation. This is a common misconception – especially when it comes to dealing with spray foam insulation. Generally, when we do traditional upgrades of air sealing, duct sealing, and insulation we will add new insulation on top of existing to increase the overall R-value (resistance to heat transfer). This is done to bring the insulation level up to current recommended level for our climate region. However, when we apply spray foam insulation to roof decking (attic ceiling), we must remove the existing insulation from the attic floor.
Two thermal barriers is NOT better than one.
The thermal barrier on a typical house (House A) is along the floor (separating the house from the slab, basement or crawlspace), along the exterior walls, and along the floor of the attic. In a house with an encapsulated attic (where spray foam insulation covers the roof decking) and all venting to the attic is closed (House B), any existing insulation on the attic floor should be removed. With an encapsulated attic, the thermal barrier is the attic ceiling/roof. The attic floor is no longer the barrier and should not have insulation along it. This process of extraction removes what would be a second thermal barrier. Having two thermal barriers creates the potential for moisture problems – including mold.
Other reasons to extract insulation:
Another reason for extracting insulation is to remove wet insulation (after a leak or flood) to avoid mold problems. Also, feces from critters could contribute negatively to indoor air quality. If your allergies get worse inside your home, removing tainted insulation and replacing it may be a good option. Generally speaking, as long as your home is properly air sealed, leaving old insulation is not a problem.
To discuss your home, call us today 205-314-3500 (Birmingham area) or 251-270-0942 (Gulf Coast area).