08-08-2010 09:23 PM
Hardiboard or tar paper & shingles if it's a roof.
08-09-2010 02:40 AM
…to the WOOD Magazine Forums, particularly to the Finishing & Refinishing Forum. I hope you will visit often. You will find a number of accomplished woodworkers and finishers here who stand ready to assist you with your finishing and refinishing questions.
Your question is a bit puzzling. OSB (Oriented Strand Board) is a construction grade product that is not intended to be finished, or for that matter exposed to the weather. It is used for sheathing, roof decks and other applications where it will be covered by building materials intended for exterior applications such as siding, shingles and even brick and stone veneer. Perhaps you can offer a bit more detail about your application and your objective...
08-09-2010 08:17 AM
Steve, you are right! My application is unusual. I put an 8x10 metal building on a 10ft wide deck and I used 3 sheets of OSB as flooring because of the spaces between the 2x6 deck planks. This left 2ft of OSB hanging out in space. I want to reinforce the OSB and use it to give me access to that end of the building, hence the need to protect it. What do you recommend?
08-09-2010 09:45 AM
I'd suggest you saw it off and build a platform, or step, of pressure treated lumber, which you can then stain with an opaque or semi-opaque stain. Unless it is a high tech osb such as Advantech it would be very difficult to protect a horizontal surface from the weather. Paint would be your only chance, but a couple of scratches would let the moisture in and it would swell and start to disintegrate.
Even if it were a more worthy material you also need to consider how to flash the junction between the building walls and the extention. Rain would hit the extension and run under the building walls, increasing the probablity of rot and other problems dramatically.
08-09-2010 01:52 PM
While this is more of a Home Improvement topic, you could use the membrane stuff that is used on roofs against ice dams. It's a peel-n-stick, rubber membrane. Be sure to overlap the joints where the OSB meets the deck. Roofers use this stuff on OSB all the time where water and ice are a problem. It is also used around door and window openings, to seal them from the elements.
08-10-2010 04:13 AM
…will soon destroy the OSB. It is not designed to resist direct exposure to the elements. I can think of nothing that you can apply that will prevent moisture intrusion short of a protective membrane which you then cover with decking material. The underside of your OSB may also be an issue if it is too close to the ground…
08-11-2010 12:25 PM
The reason I suggested the I&W membrane is that it is used all the time on roofs. Roof sheathing is OSB. Membrane is such that it will seal around any nails driven through it. Membrane comes in a roll, with a paper backing. It is a peel-n-stick application. This stuff will stick to OSB with no problems. It is used to prevent damage by ice dams on a roof, and will seal out any weather. A side benifit would be a non-skid floor surface for that shed of yours. One roll should be enough to coat both sides of the OSB flooring. When you bring the bottomedge up the wall, overlap with a second piece to cover the edge. This will also keep any water from getting to the OSB.