Water source
Identify whether water is moving through soil, coming from a slope, or arriving at a low point from roof runoff.
French drain planning
French drains work when they are part of a complete water path.
A French drain may help collect subsurface water. It is not automatically the right answer for every wet yard, downspout issue, or foundation-adjacent problem.
Collection
Discuss the trench location, aggregate, fabric, and pipe type appropriate for the property.
Conveyance
Ask how the planned route, slope, access, and crossings will allow water to move.
Discharge
Confirm where the system will terminate and whether the proposed path is practical for the site.
When to ask about a French drain
Persistent saturation near a landscaped area, water migrating down a slope, or damp soil near a structure can be reasons to seek a site evaluation. Visible surface pooling can also have a different cause.
Questions to ask a provider
Ask what water the system is intended to collect, how it will be routed, where it will discharge, what existing utilities or access issues affect the plan, and which work requires local review.