digest
Short Summary
Main recommendation: After a sewer backup or heavy-rain flood that soaks drywall, remove the wet baseboards, door casings, and drywall promptly, treat the exposed wood with a bleach-and-water solution, and let everything dry before rebuilding, because the sewage-mixed water carries bacteria that will grow and likely lead to mold inside wall cavities. The video walks through the full sequence of removing wet drywall, cleaning and drying the framing, and replacing and taping new drywall.
Key Points
- Water from a sewer backup is typically mixed with sewage, so it carries bacteria; baseboards, door casings, and door jambs should be removed and discarded.
- Wet drywall that stayed in contact with contaminated water can trap moisture behind it, creating an environment where bacteria grow, the wall smells, and mold is likely.
- The "wet test": a screwdriver should push through wet drywall easily; cut and remove drywall up to the point where it becomes firm, since moisture content above a stain line may still be too high to save.
- Insurance can cover removal and treatment of the wood, but the video notes a do-it-yourself option using bleach and water.
- Replace all drywall screws, since they rust with water exposure and the rust can stain through the mud work.
Details Worth Noting
- Concrete instructions:
- Remove baseboards, door casings, and door jambs that were touched by the water, and discard them.
- Use a screwdriver to test the drywall; if it pushes through easily, cut it out. Set the knife tip in at about doorknob height and pull around, going across twice following the studs, then cut through and use a hammer to bounce/vibrate the drywall off the screws.
- Remove all screws from the framing.
- Treat exposed wood with a bleach-and-water solution sprayed from a small spray jug, about three or four days before rebuilding, and allow about a week of drying. If the basement still smells stinky, bacteria remain and must be treated again.
- Before installing new drywall, measure and cut to fit, leaving a gap at the bottom if needed; snap a chalk line and cut on it.
- Mark stud locations by driving a new screw about two inches in (since most first screws are placed within the first inch, going to two inches avoids hitting anything), then mark the floor or subfloor so studs can be found later.
- Use premixed all-purpose compound for taping, since quick-set is unnecessary for a non-rushed job; with regular mud use three coats, or with hot mud use one fill coat plus one finish coat.
- Embed paper tape with the crease toward the back, pressing flat and removing excess; dampen the tape face and smooth the first coat over it.
- The video notes that 1/2-inch drywall is very light and easy to handle.
- It describes water typically rising about 6 inches in the example, with the bottom of the wall being the key area to check for a watermark stain.
- The video states drywall screws have low shear strength and can be knocked off with a hammer or pulled with a drill.
Bottom Line
Sewage-contaminated flood water should prompt prompt removal and drying of affected materials before rebuilding, since trapped moisture is what lets bacteria and mold take hold.
