XPost: alt.building.construction, alt.trades.building.construction.canada 
 From: Some@Guy.com 
  
 First question:  From reading past posts I know there was disagreement 
 over whether OSB or plywood makes a better roof deck.  (better from a 
 durability / water-exposure / dimensionally-stable point of view). 
 Does uncertainty still exist, or is one better than the other (for 
 roof decks that is - on 16" centers - in Ontario if that's important). 
  
 Second question:  Regarding the plywood and OSB sold in the big box 
 stores - where (I'm sure) the sales dweebs have no clue where the 
 stuff comes from, who makes it, or how it's rated - how can I find out 
 what the heck the stuff on the shelves is rated for (exterior, 
 interior, water-resistant, fire resistant, etc)??  Is there any 
 general or common knowledge of what a given big-box retailer puts on 
 their shelves?  In Canada?  In SW Ontario? 
  
 Basically, how can I make an educated and informed purchase of a dozen 
 or so 4x8 sheets of (OSB or Plywood) by knowing in advance that store 
 X has exactly the grade of product that I've determined I need? 
  
 Also, what's the difference between plywood and PDX ? 
  
 --- SoupGate-Win32 v1.05 
  * Origin: you cannot sedate... all the things you hate (1:229/2)