1 Algorithm based on impact on opinions over time - and Wikipedia. 2  Top ten most significant in history puts Jesus in the number one spot.  The list also includes Muhammad, Lincoln, Hitler and Shakespeare.
Plies vary in thickness from 1.4 mm to 4.3 mm. The number of plies depends on the thickness and grade of the sheet but at least three are required as the minimum odd number of plies. Roofing can use the thinner 5/8 (15 mm) plywood.
http://www.bobvila.com/TipLibrary/Ta...od_Weight.html. - Plywood Weight. An easy way to estimate how much a stack of plywood will weigh is to figure about 25 lbs. per 1/4 in. of thickness. For example, one 4x8-ft. sheet of 1/4-in. plywood will weigh about 25 lbs., 1/2-in. about 50 lbs., and 3/4-in. about 75 lbs. This can help you decide how many trips you need to make to get a stack home, or whether you should have it delivered.