ROOF TAR AND OSB FLOOR

[shortgmanp]

I would like to say that I have enjoyed reading the forum, and I love looking at the pics of the trailer builds. I would also like to say I have been ignorant for far too long. I had never heard of a tear drop until 3 weeks ago and want to build one. I have noticed that osb is shunned for the walls, but I was wondering if roofing tar sealed 3/4" osb would be acceptable for the floor. Thank You Greg Prater

[mikeschn]

Water and osb... no no no...

Also osb is really heavy...

I'm sure the others will be along shortly to share their thoughts with you.

Mike...

[dlmarti]

OSB is around 20% heavier.
OSB is structurally stronger and dimensionally more accurate than plywood.

Once OSB is cut/nailed/screwed, OSB looses its waterproofing (you did say exterior grade right?).

If OSB is penetrated by moisture your done, the seepage rates are MUCH higher than plywood.

Personally I would use plywood, and still go nuts sealing it. If plywood gets wet you can deal with it, with OSB its a total loss.

Also given the fact that OSB has to be treated after cutting/nailing/screwing, I'm not sure you are saving any money.

Do some google searchs and try to glean the facts. OSB isn't the devil like many builders would have you believe. It actually is a superior product in many ways. I just wouldn't uses it on a trailer. Too many transient loads/stresses, and too much moisture.

EDIT: Also I just read that OSB can't carry the screw/nail loads like plywood can. So great on floors, or over structural members, but lousy AS structural members (at least ones that use screws/nails)

[shortgmanp]

I know that OSB is structurally strong than plywood. I was just wanting to ask a question that I know the answer to. I have built houses and numerous other buildings and such. Just never a trailer. I have acsess to most any lumber I want. I just have a crapload of osb sitting around. I will use plywood. I am trying to pick out a design and aquire a descent trailer at this time. I will be reading and learning just about every day. Thanks for answering my question so quickly. I do appreciate it. Greg Prater