Testing
| Type | Cost |
|---|---|
| Hardware store charcoal kit | $15 to $30, plus a lab fee of $25 to $40 |
| Long term alpha track detector | $25 to $50 including analysis |
| Professional test with continuous monitor | $150 to $250 |
| Real estate transaction test | $150 to $300, often bundled with the home inspection |
Mitigation
| Situation | Typical range |
|---|---|
| Basement, single suction point | $1,200 to $2,200 |
| Basement, multiple suction points | $2,000 to $3,500 |
| Crawl space with membrane | $2,500 to $4,500 |
| Large or segmented foundation | $3,500 to $6,000 |
Most Spokane homes with a standard basement land between $1,500 and $2,500 installed, including the post mitigation test.
The four things that move the number
- How well air moves under your slab. Gravel under the floor is ideal and one suction point handles it. Compacted clay or sand fights the system and needs more points.
- Where the pipe can run. An exterior run up the side of the house is cheaper than routing through closets and the attic to exit the roof. It is also more visible, and some people care.
- What the foundation is. Full basement, crawl space, slab on grade, or some combination. Combinations cost the most because they may need separate treatment.
- How high the starting number is. A house at 30 pCi/L may need a stronger fan and more points than one at 5.
How to compare two quotes that are far apart: check whether the post mitigation test is included, how many suction points each one assumes, whether sealing is in scope, and what warranty covers the fan. A cheap bid usually leaves out the post test, which is the only thing that proves the work succeeded.
Is there any help paying for it
Radon mitigation is not typically covered by homeowners insurance, since it is not sudden damage. In a real estate transaction it is frequently negotiated as a seller credit, which in practice is how a lot of Spokane systems get paid for.