How much does radon mitigation cost in St. Louis, MO?

Most St. Louis homeowners spend between $845 – $2,350 on radon mitigation, with an average around $1,600. Local labor prices 6% below the national average, so St. Louis quotes tend to land at the lower end of national ranges.

Why is radon mitigation more or less expensive in St. Louis than elsewhere?

Licensed trade labor in St. Louis runs about 94% of the national average, and the best crews book out fastest in spring and early summer. Missouri weather drives material choices here, so ask contractors what they install most often in St. Louis and why.

Do I need a permit for radon mitigation in St. Louis, Missouri?

Most St. Louis, MO projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not. Always confirm current requirements with the local building department before signing a contract, and make sure the permit is pulled by your licensed contractor.

How many quotes should I get in St. Louis?

Get at least three written quotes from licensed, insured Missouri contractors. Comparing line items — not just the bottom line — is the fastest way to spot an inflated bid in the St. Louis metro market.

How much does radon mitigation cost in 2026?

Most homeowners pay between $900 and $2,500, with a national average near $1,700. Small, simple jobs land at the low end; large or premium-material jobs run well above the high end.

What is the cost per system?

Installed pricing usually runs $900.00 to $2,500.00 per system, including labor and materials. Expensive metros can run 15–45% higher than that range.

What drives the price up the most?

Scope and access. Larger quantities lower your per-system price, but difficult access, demolition of existing work, structural repairs found mid-job, premium materials and rush scheduling each add 8–30%.

Permits are typically required when the work changes structure or ties into electrical, plumbing, gas or mechanical systems. Budget $75–$600 in most cities and confirm whether your contractor pulls it — unpermitted work can block a future home sale.

How long does the job take?

Most residential projects of this type finish in one to five working days once materials are on site. Custom orders, inspections and weather are the usual causes of delay.

How many quotes should I get?

Three. Bids on the same scope commonly vary 20–40%, and the middle bid with the strongest warranty and references is usually the best value — the cheapest bid often excludes prep, disposal or permits.

Home/Cost guides/Radon Mitigation/St. Louis, MO

St. Louis metro · Missouri

Radon Mitigation cost in St. Louis, MO

St. Louis homeowners typically pay $845 – $2,350 for radon mitigation. Local labor and materials price 6% below the national average.

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St. Louis average

$1,600

Typical low

$845

Typical high

$2,350

Per system

$845 – $2,350

Sample ZIP

What drives St. Louis pricing

Local labor

Licensed trade labor in St. Louis runs about 94% of the national average, and the best crews book out fastest in spring and early summer.

Permits & code

Most St. Louis, MO projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not.

Climate & conditions

Missouri weather drives material choices here, so ask contractors what they install most often in St. Louis and why.

Instant cost calculator

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Number of suction points1 system

Quality / material level

Site access

Removal / prep work

Timing

Estimated project cost

$941 – $1,283

Most homeowners pay around $1,112

Compare quality / material level

Cost by material in St. Louis

Installed St. Louis pricing per system.

Option	Installed cost	Pros	Cons
Single-point sub-slab system	$990 – $1,350	—	—
Sub-slab with sealing	$1,350 – $1,800	—	—
Crawlspace membrane system	$1,800 – $2,300	—	—
Multi-point system with monitoring	$2,300 – $3,200	—	—

Where the money goes in St. Louis

A typical $1,600 St. Louis project, broken down by line item.

Labor0.45% · $7
Materials0.38% · $6
Permits & inspections0.05% · $1
Overhead & profit0.12% · $2

Common add-ons

Extras that show up on St. Louis quotes but rarely in the headline price.

Post-mitigation testing

$140 – $280

Crawlspace vapor barrier

$1,400 – $4,700

Sump pit sealing

$190 – $750

Continuous radon monitor

$140 – $375

Ways to save in St. Louis

Test first with a $20 kit before commissioning a system.
Route the pipe on the least visible elevation to skip cosmetic upgrades.
Collect three written bids on an identical scope — spreads of 20–40% are normal.
Book in the off-season and stay flexible on the start date to save 5–15%.
Bundle nearby work into one mobilization so you only pay setup and travel once.
Ask what the contractor would change to cut 10% without hurting durability.

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More St. Louis research

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