What does the crawl-space part of the system do?
EPA describes sub-membrane suction as drawing soil gas from beneath sealed sheeting and venting it outdoors. The membrane, collection arrangement and fan belong to a designed system. A loose ground cover is not evidence of radon reduction.
At the estimate, identify existing liners, seams, piers and plumbing penetrations. Ask what can remain, what needs repair and who prepares the space. Describe restricted access beforehand. Photographs from a safe, accessible position are useful; do not enter an unsafe crawl space to obtain them.
How should a basement and crawl space be assessed together?
Start with a sketch showing the original house, additions, basement slab and crawl-space boundaries. Mark access doors and the rooms above each area. Explain whether you have an existing sump, drainage system or earlier mitigation equipment. These details help the contractor define the investigation instead of treating the whole lower level as one uniform space.
Ask which areas the proposed collection arrangement serves and what would trigger a design change. Do not assume that one suction point or one fan is always sufficient, or that each foundation section automatically needs a separate fan. The answer belongs in the property assessment. See our guide to combined basement and crawl-space foundations.
Encapsulation, crawl-space mitigation and basement mitigation: what differs?
Use the project purpose to compare proposals. Encapsulation addresses the crawl-space enclosure and may be part of a broader moisture project. Radon mitigation must address soil-gas collection and verification. Basement slab work concerns a different foundation surface. The same contractor may discuss several tasks, but the written quote should distinguish their responsibilities.
An existing liner deserves inspection before either accepting it unchanged or paying to replace it. Ask whether membrane preparation, attachment details and repairs are included. If another trade handles moisture or structural work first, agree on the handoff and who checks readiness. A finished-looking crawl space cannot substitute for the indoor test report.
What should a Jefferson County quote include?
Request a description of each foundation area covered, proposed collection points, membrane work, pipe route, fan location and electrical arrangements. Add access preparation, debris removal and restoration responsibilities. Separate required work from optional appearance improvements so two proposals can be compared fairly.
The quote should also identify the follow-up testing arrangement, warranty terms and process if the result calls for further investigation. Ask what could change the price after inspection and how changes would be authorized. For a Hillsboro or De Soto appointment, provide the address and access details when confirming scheduling. No countywide price can establish the scope of your crawl-space project.
Does a walkout or unusual foundation change the plan?
Tell the assessor about a walkout, stepped slab, block walls or an addition even when those details seem unrelated to the crawl space. A door to the yard does not describe the foundation underneath the occupied rooms. A photograph of the house exterior can complement your lower-level sketch.
Our walkout-basement guide helps organize those questions. If the project involves block foundation walls, read the block-wall assessment guide before the visit. These are planning resources, not a prescription for a particular collection method.
What evidence should I keep after installation?
Keep the original test, accepted scope, photographs of completed work, operating instructions and follow-up report together. Ask the installer to show you the system indicator and explain what changes require a service call. Discuss how later plumbing or electrical work should protect the membrane and preserve equipment access.
Air Sense can discuss the property and proposed work at 314-664-9807. This site is an Air Sense Environmental service resource, not a separate Jefferson County office. Ask to see examples relevant to your foundation rather than assuming a photograph of another home establishes the result yours will achieve.
Questions before you book
Can I reuse my existing crawl-space liner?
Possibly. Its condition and suitability for the proposed system need assessment. Ask the contractor to document the repair or replacement scope before work begins.
Should the test be placed in the crawl space?
Arrange a measurement plan for the occupied home. Describe the foundation and rooms to the tester rather than treating a crawl-space reading as the living-area result.
Can I finish the project before selling?
Discuss the installation schedule and follow-up reporting deadline separately. Give Air Sense your transaction dates before accepting an appointment.