Put the condition in writing first
Note where it's happening, when, its relationship to weather, and any change over time. Photos and a rough measurement or two help the first conversation.
Read the local context
A city founded in 1775 has housing from every era, and the oldest of it behaves quite differently below the floor. In the neighborhoods that grew up around Transylvania University and the early town, crawl spaces are shallow, irregular and often partly stone, with ground cover added piecemeal across generations -- so what is achievable there is set by access and existing conditions long before a product is chosen. That is a different starting point from the vast twentieth-century subdivision ring, where the spaces are consistent, built to one practice, and mostly a question of correcting ventilation and ground moisture. Establishing which Lexington a house belongs to is the first real step in scoping this work.
Ask what will be hidden
Because karst limestone can move water in unpredictable directions underground, the plan needs to cover drainage routing, standing water, liner attachment, termite-inspection access, air sealing, equipment placement, and existing framing condition -- in that order. The written scope should capture what was inspected and prepared, since the liner will cover all of it once installed.
Compare proposals in full
Check for protection, access, materials, permits, testing, cleanup, restoration, exclusions, warranties, and change-order rules.
What official local sources add
Karst is why crawlspace moisture here behaves less predictably than a slope map suggests. In limestone terrain with irregular underground drainage, water can arrive at a crawlspace from a source that is not obviously connected to the property, and it can disappear somewhere equally unhelpful — which is exactly why sealing a space before establishing where the water comes from tends not to hold. Article 19 floodplain administration and the MS4 stormwater program matter mainly to the exterior drainage that has to precede the liner, not to the liner itself.
Sources were reviewed 2026-07-20. Confirm parcel-specific flood zones, karst/soil conditions, permits, and current requirements with the relevant authority before authorizing work.