The tenants did their own tests and found asbestos in five samples.
Advice or booklets with tips on finding asbestos in the home are available from many local environmental and public-health agencies.
The engineer who inspected the house for them had initially found asbestos only in the basement.
The Friends' hopes were again temporarily dashed when they found more asbestos than anticipated.
"What if somebody who could focus in on it said, 'We find asbestos in the hall where your son plays,' Would you become more active?"
Investigators have retested 21 of those schools and found asbestos in each.
Once the fire was put out, firefighters found cancer-causing asbestos hanging from the roof.
New York City had a crash program to find and remove dangerous asbestos in schools after a 1986 Federal law.
Nor did it react when the City Comptroller's office found asbestos in dozens of schools two years ago.
Using these criteria, Berger found excessive asbestos in 24 of the 31 floors it tested, or 77 percent.
