Out of sight, but not out of the house
Many Middle Tennessee homes sit over a crawlspace, with drain lines running beneath the floor. When a pipe cracks, separates or clogs, sewage can leak into the crawlspace for a long time. The usual signs are an odor in the house, especially on humid days, damp floors, insects, or a plumber or home inspector who spots it.
Because crawlspace air moves up into living areas, contamination underneath affects the comfort of the whole house. The same is true of rental houses and small commercial buildings built over a crawlspace.
Leaks under a kitchen, laundry room or bathroom are the most common, since those rooms carry the most drain lines. Older cast iron pipes and joints that have shifted over time are frequent culprits, though only a plumber can confirm the cause.
What gets contaminated below the floor
- Fiberglass batt insulation between floor joists
- Plastic vapor barrier over the soil
- Soil and gravel beneath the leak
- Floor joists, beams, piers and the underside of the subfloor
- Ductwork exteriors and other items stored in the crawlspace
How we clean a crawlspace
- Inspection We confirm the plumber has repaired the line, map the affected area and check for safe access and electrical hazards.
- Remove soaked materials Contaminated insulation, vapor barrier and debris are bagged and carried out.
- Treat or remove soil Soil and gravel under the leak are treated, and heavily saturated soil is removed where practical.
- Disinfect framing Joists, subfloor, piers and foundation walls are cleaned and then disinfected per label.
- Dry the space Dehumidifiers and air movers dry the crawlspace while moisture readings are logged.
- Restore the barrier A new vapor barrier is installed if that is part of the agreed scope, or the space is left ready for the contractor who will install it.
Working conditions underneath
Crawlspaces are cramped, dark and often wet, which makes sewage cleanup physically demanding. Our crew wears coveralls, gloves, boots and respiratory and eye protection, and we set up lighting and access before work begins. CDC's guidance on contaminated water, including protective gear and cleaning before disinfecting, applies directly.
Bagged insulation and debris have to be carried out through a small access opening, so we plan a protected route from the crawlspace door to our vehicle. That keeps contaminated material away from your yard, porch and living spaces.
Drying a crawlspace also takes patience. Soil holds moisture, and outdoor humidity in a Tennessee summer can slow progress, so we keep monitoring until readings show the framing has dried.
What homeowners should avoid
- Do not crawl into a sewage-contaminated crawlspace without protective equipment.
- Avoid running a crawlspace fan that pushes air into the house until cleanup is done.
- Do not lay new vapor barrier over contaminated soil.
- Keep using affected drains to a minimum until the plumber confirms the repair.
Buying or selling a home
Crawlspace sewage often comes up during a home inspection. Buyers, sellers and agents can ask us for a written scope and photo documentation of the cleanup. We document what we did; any warranty, clearance testing or disclosure question goes to the parties' inspectors, attorneys or agents.
Other trades
Pipe repair is the plumber's job. Mold growth beyond what our cleanup addresses goes to a mold remediation professional, and duct repair or replacement to an HVAC contractor. Structural repairs to joists or sill plates go to a contractor. For lingering odor, see sewage odor removal, and for backups inside a basement, sewage backup cleanup.