Subflooring and subfloor products – bob vila
When plywood was developed to replace solid-board sheathing for subfloors and decking, builders were generally reluctant to switch to the new product, which ultimately became the standard for subfloor applications. When OSB came on the scene as an alternative to plywood, detractors were quick to point out its deficiencies. The truth is that plywood and OSB each have strengths and weaknesses when used as exposed decking or subflooring.
When a roofless, partially built structure takes on water, both plywood and oriented strand board (OSB) used for floor decking can absorb water, swell, delaminate, and require sanding or replacement before finish flooring can be installed. The fix is to use water-repellent or water-resistant products in place of ordinary plywood or OSB.