Publication Types & Categories: Technical Article

“Algae: The Growing Problem” by Kris Ammerman

January 01, 2007

What are you going to do about that black stuff on your old roof?” a friend asked me this summer after viewing the new addition to my home and comparing its pristine, clean shingles to the adjacent, original, 10­-year-old roof. “What is that stuff?” I asked. “I think it's mold,” he replied. “What can you do?” I shrugged. “You're the one who works for the roofing people,” he said. “Find out.” So over the next few weeks, in the course of my job as director of publications for RCI, I asked a few of the consultants I routinely deal with about the “black stuff” on my roof. I got some interesting and varied suggestions (some being unprintable), but the most ultimately enlightening (and frustrating) one came from Interface's senior editor and my friend Lyle Hogan, RRC, FRCI, PE: “You're a reporter, aren't you?” Forced, reluctantly, to find my own answers, I did some research.

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Waterproofing Under Green (Garden) Roofs – Part 2 of 2

February 01, 2005

This is part two of a two-part series on waterproofing mem­branes under green (garden) roofs. The first part, published last month, traced the history of waterproofing membranes under plazas and earth-covered, below-grade spaces, and discussed the various types of waterproofing systems currently marketed and their advantages and disad­vantages for use under green roof systems. This part covers the attributes of candidate membranes and offers a list of minimum physical properties proposed to satisfy the specific needs for those membranes exposed to continuous moist environments, aggressive chemicals, root invasion, and abusive maintenance. Additionally, it dis­cusses failures and offers case studies to illustrate them.

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