The presidential shingle is a thicker material with a distinct design. It reminds people of puzzle pieces and is appreciated best on high pitch roofs. It was a product that was created to imitate or resemble traditional wood shake roofs.
Presidential Shake and Presidential Shake TL are the brand names for CertainTeed, but there are other manufacturers that produce a similar design like GAF's Grand Sequoya and Grand Canyon. Most major manufactures have a designer line with this "puzzle piece" look. Due to the shingle's thickness they are marketed as "50 year" shingles or "limited lifetime"
We recently installed Certainteed's Presidential Shake series on a house in Laguna Niguel. Previously it had wood shake on it, but the roof was past its expected lifespan. In years gone by, wood shake roofs were installed without any plywood sheathing. We re-decked the entire home as well as replaced the home's entire fascia.
When getting a an estimate for a roof that has wood shake, all roofing contractors should be able to inform you whether there is plywood underneath or not.