Home > How To > Roofing > Flashing a Leakproof Valley Roofing Posted on: March 01, 1998 Share on Facebook Share on Twitter Share on LinkedIn Flashing a Leakproof Valley Careful installation of membrane, metal flashing, and shingles is key to a leakproof valley By Tom Brewer Download the PDF version of this article. (242.28 kB) 1 2 Next About the Author Tom Brewer