Document what you're noticing
Track the location, timing, any weather pattern, and whether things are getting worse. Photos and rough measurements help frame that first call.
Read the local context
Champaign is basement country, and that is worth saying plainly before this work is scoped. The city grew from an 1855 railroad settlement called West Urbana into a chartered city by 1861, and both that era and the twentieth-century expansion that followed favored full basements over crawl spaces. Where crawl spaces do turn up -- under additions, porches, converted outbuildings and some older houses near the original town -- they tend to be shallow, tight, and never intended for anyone to work in. The prairie soil beneath them is the complication: it drains slowly and holds moisture for days after rain, so those spaces stay damp for reasons the grading above them will not explain, and access usually sets the limit on what is achievable.
Ask what will be hidden
A written scope should explain the preparation and verification that will no longer be visible at completion, not just the finished appearance.
Stack proposals against each other
Look for protection, access, materials, permits, testing, cleanup, restoration, exclusions, warranties, and change-order terms.
What official local sources add
Encapsulation itself is not permitted work, but the drainage that has to precede it frequently is. If sealing a crawlspace involves routing collected water to a new or modified connection to the municipal stormwater drainage system, Champaign requires a permit for that connection. Exterior excavation to correct the water arriving in the first place is land-disturbing activity the city permits. The practical sequence is therefore: establish where water is coming from, settle where it will go and whether that needs permission, and only then choose a liner.
Sources were reviewed 2026-07-26. Confirm parcel-specific flood zones, historic-district status, permits, and current requirements with the relevant authority before authorizing work.