Q:

We are two weeks from having trusses and a roof put on our new house. The rains are killing us. We painted the OSB subfloors before the rains and have been vacuuming up water after each storm. We are dreading putting the hardwood floors down. How much damage can this rain do to our subfloors?

Asked by “Collen1 Runyen” via GreenBuildingAdvisor.com, None

A:

Martin Holladay: Once the house is dried in and the OSB has dried out, use a belt sander to take down the swollen edges of the OSB. If the swelling is more than your belt sander can fix, install a layer of tongue-and-groove plywood over the ruined OSB.
If you ever have a new house built again, be sure to specify a material such as Advantech that’s made to withstand exposure to the elements during the building process.

David Meiland: You probably don’t need to worry at all. If there are areas of ponding on the floor, drill a few holes to let the water drain through. Once the house is closed in, start running a dehumidifier and perhaps some heaters (not salamander heaters, which add moisture to the air) to start drying all of the materials. Continue doing that and monitoring the humidity in the house with an accurate hygrometer until the house is complete or the levels are stable without the dehumidifier. Bear in mind that drywall, paint, tile, and other trades add a lot of moisture to the air, as do the sweating, breathing installers.
If you’re still concerned, contact the OSB manufacturer and talk to a tech representative about their specific product.