Source:

1. “The Most Common Commercial Roofing Problems Solved.” Roof Repair | Renco Roofing | Phoenix, AZ | Roofing Company, 22 Mar. 2019, www.rencoroofing.com/the-most-common-commercial-roofing-problems-solved/.
2. “Top 5 PHX Roof Problems | Allstate ROofing.” Allstate Roofing of Arizona, 9 May 2019, www.allstateroofingaz.com/roof-repair/the-top-5-phoenix-roof-problems/.