If you are comparing crawl-space work in Indianapolis or Marion County, keep two questions visible: how will the project control moisture, and how will you check radon? A clean liner, lower humidity or a less musty smell does not provide a radon test result.
Marion County has a local starting point for testing, and Indiana provides a separate route for checking radon-professional credentials. Use both while planning the work so testing, moisture repairs and any mitigation do not fall between different contractors.
In this guide: Marion County testing · Different scopes · Credential check · Contractor coordination · Project record · Common questions
1. Start with Marion County’s testing resource
The Marion County Public Health Department Indoor Air Quality Program advertises a free radon test and gives 317-221-2266 as the request number. Ask the program about current availability, address eligibility, test placement, preparation and how results will be provided. A free-test offer does not establish that mitigation or crawl-space repairs are funded.
Tell the testing professional about the planned work and any existing radon system. Mention a basement, slab addition or other foundation section as well as the crawl space. Do not select a test location simply because it is the dampest spot; follow the testing instructions for the home.
Keep the full report, including test dates and location. A number copied into a contractor’s estimate without that context is harder to interpret or compare later. If you live outside Marion County, use Indiana’s homeowner radon resources rather than assuming the county program covers your address.
2. Distinguish moisture control from radon reduction
Moisture work may address liquid-water entry, ground vapor and humidity. PNNL’s crawl-space retrofit guidance calls for addressing bulk water and moisture before sealing and insulating. A moisture proposal should explain the observed source and the job of each proposed component.
Radon work has a different performance question: what do the measurements show, and what reduction approach fits the house? The EPA’s 2025 Consumer’s Guide to Radon Reduction describes a crawl-space method that uses a sealed ground sheet, pipe and fan to draw gas from beneath the sheet and exhaust it outdoors. It also explains that sealing alone has not consistently produced meaningful radon reductions.
That distinction matters when comparing two estimates with “sealed crawl space” in the title. Ask whether the price covers moisture control, a designed radon-reduction system, or both. Do not add a fan or alter vents yourself on the assumption that more airflow solves either problem.
For broader context, read our encapsulation and indoor-air-quality guide. Use the drainage guide when standing water is part of the inspected problem.
3. Check the credential for the task being offered
Indiana Department of Health’s homeowner page distinguishes radon testing and mitigation roles and links to the state’s professional-license search. A person qualified for a testing role is not automatically qualified for mitigation. A crawl-space service listing is not evidence of either radon credential.
Ask for the name of the person responsible for the radon work, the relevant Indiana credential and the company named on the proposal. Check the current record and task category through the state’s linked search. Keep the result with the estimate rather than relying only on a logo, sales statement or an unrelated trade credential.
If a company will subcontract part of the work, ask who will do it and who will provide the report. That is especially useful when one salesperson presents a combined moisture-and-radon package.
4. Agree on the sequence before materials cover the work
A practical coordination question is: “What does the next contractor need before this stage is closed up?” Ask the moisture contractor and radon professional to identify their shared details in writing. Those may include the ground membrane, penetrations, sump cover, access opening and any existing mitigation components.
Use a simple responsibility list:
- Who investigates and corrects the water problem before enclosure?
- Who specifies any radon-related membrane and sealing details?
- Who makes and reseals penetrations when plumbing, drainage or other equipment is installed?
- Who reviews changes that could affect an existing radon system?
- Who orders the follow-up test and explains the result?
EPA’s radon guidance recommends testing again after major remodeling or HVAC changes, and after mitigation to check that levels have fallen. Discuss the appropriate before-and-after testing plan for your project rather than using a prior result as a permanent clearance.
As one existing local service example, Indiana Crawl Space Repair says on its company website that it provides encapsulation, drainage, waterproofing and structural repairs in the Greater Indianapolis area. That supports a moisture-work inquiry; it does not verify a radon license or establish that radon services are included. Confirm scope and address coverage directly.
5. Keep separate evidence for separate outcomes
Save one folder containing the inspection findings, each written scope, the testing reports and the final handover. Label the records by what they establish:
- Water and moisture: the reported entry points, correction work, installed equipment and monitoring instructions.
- Radon: test location, dates, full results and the professional’s follow-up advice.
- Coordination: photos before concealment, responsibility for later penetrations and the service contact for each system.
Our crawl-space quote comparison guide can help organize exclusions, maintenance and completion documents. Do not mark both concerns resolved because one contractor has finished its part.
Common questions
Can a humidity reading tell me whether radon is low?
No. Humidity and radon are different measurements. Follow a radon-testing protocol; a moisture reading or smell check cannot substitute for the result.
Does Marion County’s program include mold sampling?
The department says it does not sample for mold. It can assess whether a leak or another moisture source contributes to growth and offer guidance. Ask it about the service that matches your concern.
Web-source extracts reviewed October 14, 2026; extracts may lag the original pages. Confirm current program details and availability with the relevant office. This is a project-planning guide, not a diagnosis of an individual home. Agency resources support the local testing and credential routes; the coordination checklist is an editorial tool. Directory listings are not endorsements.