Wet Drywall Flood-Cut Calculator
Work out the cut height, sheets of drywall and cost to replace water-damaged walls.
Estimates use typical industry ranges and published methods. They are not a quote. An on-site moisture inspection sets the actual scope.
Drywall that can usually be dried
- Wet from clean water (Category 1)
- Drying started within about 24–48 hours
- Still firm, not swollen, crumbling or sagging
- No mold, and the paper face is intact
- Not covered by vinyl wallpaper or other finishes that trap moisture
Drying in place often involves removing baseboards and drilling small holes near the floor, hidden behind where the baseboard goes, to push dry air into the wall cavity.
Drywall that should be replaced
- Any drywall touched by sewage or outdoor floodwater (Category 3)
- Soft, crumbling, swollen or sagging sections
- Visible mold or a persistent musty smell
- Walls with wet insulation behind them that can't be dried
- Ceiling drywall that has sagged under water weight
How a flood cut works
Instead of patching around the wet area, crews snap a level line and cut the drywall off below it all the way around the room. This exposes wet insulation and the bottom plate so they can dry and be disinfected, and it makes re-hanging easier. The cut is usually made about 12 inches above the highest moisture reading, rounded up to a standard line:
- 2 ft cut — for water that wicked up to about a foot. Half sheets go back horizontally.
- 4 ft cut — for higher wicking or deeper water. One full horizontal sheet.
- Full height — for water several feet deep or walls wet from above.
What replacement involves
After cutting and drying, crews replace insulation, hang new drywall, tape and finish the seams, match the wall texture, prime and paint, then reinstall baseboards. The calculator above estimates the cut height, sheets and cost. On interior walls without insulation, drying the cavity is enough before re-hanging.