What is the weight (in pounds) of a 1/2" x 4' x 8' and a 3/4" x 4' x
8' sheet of OSB (oriented strand board)?

Hi hanni05,

A 1/2" sheet of oriented strand board weighs about 52-53 pounds and a
3/4" sheet weighs about 78-80 pounds.

It appears that it is not possible to be more precise because the
density of the material is not standardized and can vary depending on
the moisture content.


Sources

The Canadian Wood Council has a web page with tables of thicknesses and weights.

http://www.cwc.ca/products/osb/sizes.php

There are two tables with slightly different results for two different
grades of OSB.  For a 1/2" sheet, the weight is 53 pounds for OSB-1
and 52 pounds for OSB-2.  For a 3/4" sheet, the weight is 80 pounds
for OSB-1 and 78 pounds for OSB-2.

A note explains "Panel weight calculated on the basis of 640 kg/m^3
(40 lbs/cu.ft.) density and nominal thickness."

A web page from Goldboard Development Corporation has slightly lower
density values of 625 and 39, respectively.

http://www.goldboard.com/products/equivalency.htm


Additional Links

An article by Paul Fisette on the website of the Building Materials
and Wood Technology program at the University of Massachusetts,
Amherst says (implicitly) that a 3/4" sheet weighs 80 pounds.
http://www.umass.edu/bmatwt/publications/articles/osb_vs_plywood.html

This page from the High School Tech Production website lists the
weight of a 3/4" sheet as 85 pounds.
http://www.hstech.org/howto/material/plywood.htm


Search Strategy

I used various combinations of search terms to find these pages, including:

osb sheet pounds
osb oriented strand board
osb OR "oriented strand board" sheet +weight
osb OR "oriented strand board" kg
osb OR "oriented strand board" lb OR lbs
osb density


I hope this information is helpful.

Regards,

--efn