Q: What definitive information do you have that new growth cedar is less effective as a roofing shingle than old growth cedar?
A: I do not have definitive information to show that either Old Growth or New Growth is advantageous in making wood shingles.
The Red Cedar Shingle and Shake industry has had several organizations representing the Shingle and Shake Mills over the past 100+ years.
In the late 1980’s the associations joined together and formed the Cedar Shake and Shingle Bureau. I understand this to be the dominate
group representing the Shake and Shingle industry today.
New Growth Cedar is a result of planting and harvesting in an attempt to provide Cedar for the established market with the intention of saving the
Old Growth Cedar. There is not a significant difference between “Old Growth” and “New Growth” as far as molecular structure of the cedar product.
It appears to be more difficult to get a significant amount of Shingles from “New Growth” than from the “Old Growth” Cedar that was so abundant in the Pacific Northwest and Canada in the 20th Century.
The Cedar Shake and Shingle Bureau no longer uses the Term “New Growth” and “Old Growth” in describing shingles. It seemed to be meaningless and often misunderstood.
Thank You for your question. Hope this answers it.
Ask A Roofer - John Stout from Go Roof Tune Up