which side of osb faces up

[handy_wo_man]

im replacing my subfloor in a mobile home in 3 of the rooms right now does it matter which side (smooth or roof) i should face up. ive been putting the rough side up because the smooth side seemed as if it had maybe a moisture barrier on it and i figured since it did it would be best facing the outside of the floor and im covering this floor with sheet vinyl anyway, since its rough i thought maybe the glue would adhere better too so does it matter and if it does ive already installed 7 sheets this way will it hurt anything in the long run??

[jadnashua]

Probably won't hurt anything, but depends on how rough the rough side actually is. Sheet vinal telegraphs surface irregularities through. Depending on the brand, some do contain a wax or other water resistant coating. It is designed to help prevent damage in new construction before the roof goes on. SOme are better than others. Now, if you are planning a layer of say luan on top of it first, makes absolutely no big difference.

[LLigetfa]

All the OSB I ever laid always had "This Side Up" printed on the rough side. I think the roughness is a safety consideration more than anything but I'll buy the textured for glue theory too.