Drying out a wet crawl space under an Oklahoma City home

What happens to a house when the crawl space stays wet

A crawl space shares its air with the house above. Standing water evaporates into the joists, the subfloor and the insulation between them, and some of that damp air moves into the living space through gaps around pipes and ducts. The first sign upstairs is often a musty smell or floors that feel cool and soft.

We start by pumping out standing water and finding where it came from. Wet fiberglass batts come down, torn vapor barrier comes out, and dehumidifiers and air movers run under the house while we read the joists and subfloor each day.

When the wood reaches its dry target, new vapor barrier goes down over the soil and insulation goes back between the joists.

Most wet crawl spaces we see show one or more of these three problems, often together.

Standing Water

Pooled water under the house comes from a leaking supply or drain line, a failed water heater, or rain running toward the foundation and finding the low spot inside. We pump it out, then trace it. A plumbing leak gets repaired. Surface water usually points to grading, gutters or downspouts dumping next to the house, and drying the space without fixing that only buys time until the next hard storm rolls through.

HomeAdvisor gives a normal range of $4,500 - $8,000 for crawl space repair, average $6,000, and puts crawl space water damage restoration between $2,000 and $10,000.

Wet Insulation Under the Floor

Fiberglass batts between floor joists soak up water, then sag, fall or hold moisture against the subfloor. Once soaked, they rarely recover their shape or insulating value, so we bag and remove them. The joists and subfloor dry much faster once the batts are out of the way and air can reach the wood. New insulation goes back only after the wood reads dry and the moisture source is fixed.

Torn or Missing Vapor Barrier

The plastic sheet on the crawl space floor keeps ground moisture from rising into the framing. When it is torn by service workers, pushed aside by water or missing entirely, the bare soil breathes moisture straight up into the wood above it. We remove damaged sheeting, let the soil surface dry, and lay new barrier with overlapped, taped seams, running it up the foundation walls where the space calls for it.

How long a wet crawl space takes to dry

Pumping takes hours. Drying the framing takes longer: after a plumbing leak caught early, joists often reach their dry target in three to five days with dehumidifiers running. A space that held water for weeks, or has wet soil and no barrier, can take a week or more before new barrier and insulation go in.

How we dry out a crawl space

1. We inspect and photographWe go under the house and record the water depth, the source and the condition of joists and insulation.
2. We pump and removeStanding water is pumped out; wet insulation, debris and torn barrier come out in bags.
3. We dry the framingDehumidifiers and air movers run under the house, with joist and subfloor readings every day.
4. We treat and repairMold on the wood is cleaned and treated, and damaged joists or subfloor are repaired.
5. We close it back upNew vapor barrier and insulation go in once the wood reads dry and the source is fixed.

Clay soil and older houses over crawl spaces in Oklahoma City

Crawl spaces in Oklahoma City sit on demanding ground. An Oklahoma Agricultural Experiment Station bulletin traces the clayey soils of central Oklahoma to Permian clay beds and shales and rates some of them high for shrink-swell, so water left pooling under a house can swell the soil around the piers. Age matters too. About 80 percent of the properties in Jefferson Park were built between 1914 and 1931, and houses of that era are more likely to stand over a crawl space than on a slab, often with old drain lines running through it.

What a crawl space water job should cover

Some crawl space quotes stop at pumping. A full job includes these steps.

• Pumping standing water and removing mud or debris
• Finding the water source and naming it in writing
• Removing wet fiberglass insulation from between the joists
• Removing torn or contaminated vapor barrier
• Drying with dehumidifiers until joist readings reach target
• Checking joists and subfloor for rot or mold
• New vapor barrier with overlapped seams
• Reinstalled insulation after the wood is dry

What decides the cost of drying a crawl space

Crawl space jobs are priced by access and by how much has to come out from under the floor.

• Clearance. Two feet of clearance means slow, cramped work compared with a space you can kneel in.
• How much water stood. A few inches pump out quickly; a flooded space needs mud removal and longer drying.
• Insulation removal. Every soaked batt is pulled, bagged, carried out and later replaced.
• Vapor barrier. Replacing a torn sheet costs less than full encapsulation with sealed seams.
• Wood condition. Rotted or moldy joists and subfloor need repair or treatment before closing up.

Crawl space water questions from Oklahoma City homeowners

Often booked with this job