This week, Hendricks topped Forbes' recent American's Richest Self-Made Women list for the seventh consecutive year.
Her estimated $20.9 billion net worth comes largely from her roofing materials company ABC Supply, which she co-founded with her late husband Ken Hendricks in 1982.
Roofers often bought directly from individual manufacturers, locking them into an ecosystem and allowing manufacturers to drive up prices.
They took out a $900,000 loan from Beloit Savings Bank and pledged everything they owned to launch their company and fill that gap, Hendricks said.
"We felt like we [roofers] weren't being treated with respect," said Hendricks.
Persons:
Diane Hendricks, Hendricks, Ken Hendricks, Ken, Forbes, Roofers
Organizations:
Forbes, ABC Supply, Beloit Savings Bank