Organizing lumber in a garage can depend on the intended use of the lumber. If you are storing pieces to keep them away from the elements or will not be using them for projects in the near future, then consider using the roof beams of the garage or tops of high shelves for storing long pieces of lumber. Smaller pieces can be stored horizontally in a bin or vertically in a clean trash bin.
To be an ADHD specialist requires many hours of study. As a life-long learner, I am glad that Simplify Experts values learning and education. To support my learning I am a member (called a subscriber) of the Institute for Challenging Disorganization (ICD.)
ICD is very focused on its mission: to provide education, research and strategies to benefit people challenged by chronic disorganization. Members include professional organizers as well as mental health professionals and academics.
