Fixing a Wet Basement in a 100-Year-Old Iowa House: Curtain Drains, Grading, and Sump Options

Regrading with plastic and rock around a century-old Iowa foundation is a "curtain drain" concept but often fails to intercept water before it enters the basement.

Better: Exterior Curtain Drain

1. Trench 12-18" wide along foundation to footing depth.
2. 4" perforated pipe on 6" gravel bed, holes down.
3. Gravel to within 12" of grade, filter fabric, backfill.
4. Daylight to lower grade or sump pump.

Critical: Slope and Discharge

Must achieve 1% slope to daylight. In flat Iowa, may need sump basin with pump to eject water.

Iowa-Specific Resources

• Iowa State Extension: PM1560 "Wet Basement Solutions"
• RuralHomeTech.com basement drainage guide
• UTK "Wet Basement" publication

Regulations

Check county rules on discharge—cannot dump on neighbors or into streams without permit.

Interior Alternative

Interior French drain + sump pump is cheaper, less disruptive, but doesn't stop wall dampness.

Exterior curtain drain is gold standard. Get a pro design for your specific site.