I just found a neighborhood of this stuff, degraded to a fine powder, can be disturbed by BD, This foam (back East) was urea/formaldehyde based and sometimes toxic. We're not using BD until I have the stuff tested. Anyone know about best practices or protocols for dealing with this?
Oh no it was used country wide & if worried I would not depressurize the house & instead opt to pressurize it if you really need the numbers to start. (I could have sworn that was all handled under a class suit, but that could be something else) I would recomend going with a dense pack cellulose, but before blowing it in, see if they can use that hole to vacuum the bulk out.
By the way, BD= Blower Door. And the dust is incredibly fine, offering no resistance to a probe. We are having it tested and doing some thermal imaging now that we have winter (ish) conditions in north central Nebraska.
Sean's suggestion is to turn the fan around. If the material is friable it won't be pulled into the house.
Barring some huge kitchen vent you are likely to get a very similar CFM50 number.
Here's a quote and link from the EPA. There is also good info on the InspectAPedia web site, including pictures. Look it up under UFFI (Urea Formaldehyde Foam Insulation)
"During the 1970s, many homeowners had urea-formaldehyde foam insulation (UFFI) installed in the wall cavities of their homes as an energy conservation measure. However, many of these homes were found to have relatively high indoor concentrations of formaldehyde soon after the UFFI installation. Few homes are now being insulated with this product. Studies show that formaldehyde emissions from UFFI decline with time; therefore, homes in which UFFI was installed many years ago are unlikely to have high levels of formaldehyde now."
We replaced a ceiling in a room during a reno project for a customer recently and found it in the sidewalls of this old two story. There were a lot of voids and gaps and it was very powdery when touched.
Looking back (20/20 hindsight) the issue looks kind of silly. "Let's tighten the snot out of buildings and walk away - what could go wrong?"
ACH goes way down, moisture goes way up, every piece of furniture and flooring starts off gassing to beat the band, and it all stays nicely contained.
I suspect if they'd installed mechanical ventilation/had todays requirements those homes might not have had problematic IAQ issues.
What did you find about the dust?