How Long French Drain Installation Takes
A shallow exterior French drain in an accessible yard takes 1 to 2 days. An interior basement perimeter system takes 2 to 4 days of work inside the house. An exterior drain excavated to the footing takes 3 to 5 days or more. Permits, utility marking, weather, and restoration add calendar time beyond the work days.
Drainage projects are refreshingly quick compared to most home improvements: the work itself is measured in days, not weeks. This guide gives realistic timelines by drain type and flags the things that stretch a 2-day job into a 2-week saga.
Timelines by drain type
Shallow exterior / yard drain: 1 to 2 days. A trencher opens the trench, pipe and gravel go in, fabric wraps it, and the trench is backfilled. In an easily accessible yard with no resloping needed, a crew finishes a 100-foot run in a single day. Interior basement perimeter: 2 to 4 days. Day one is concrete breaking and excavation along the perimeter (loud, dusty); day two is pipe, gravel, and the sump pit; day three is concrete re-pour and cleanup. The concrete then needs several days to cure before you move heavy items back. Exterior to the footing: 3 to 5 days or more. Deep excavation with shoring is slow, foundation waterproofing membrane application adds a day, and backfill must be compacted in lifts. Large perimeters and difficult access stretch this toward two weeks. Crawl space: 1 to 3 days depending on access height and length.
What adds calendar time beyond work days
Permits: 1 to 4 weeks. Simple yard drains often need no permit; foundation-adjacent excavation and storm-drain tie-ins usually do. Apply early. Utility marking: 2 to 3 business days. Calling 811 is free and legally required in most states; utilities mark lines within a few business days, and you cannot dig until they do. Weather. Excavation in saturated soil is miserable and sometimes impossible; heavy rain pauses exterior work. Interior work proceeds regardless. Restoration: 1 to 2 weeks after. Sod, grading touch-ups, and concrete curing happen after the crew leaves. Contractor scheduling: 2 to 6 weeks. Good drainage contractors book out, especially after major storms when everyone calls at once.
The project sequence, start to finish
Week 1: assessment and quotes; call 811; permit application if needed. Week 2 to 3: permit issuance and contractor scheduling. Work days: marking, excavation, pipe and gravel, outlet construction, backfill, rough restoration. After: concrete curing (interior), final grading and sod (exterior), sump pump testing. From first call to finished yard, plan 4 to 8 weeks for exterior work and 3 to 6 weeks for interior, with most of that being waiting, not working.
Living through it
Interior work means jackhammers inside your house for a day or two: plan to be elsewhere with pets and kids, and move everything two feet from the basement walls before the crew arrives. Exterior work means heavy equipment on the lawn and a torn-up yard for a week or more; mark sprinkler heads, invisible fences, and septic locations before digging. For both, confirm the payment schedule in the contract: never pay the full amount before the work passes inspection.
The bottom line
The digging is fast; the waiting is slow. A yard drain is a 1 to 2 day job inside a month-long project; an interior basement system is 2 to 4 days of disruption inside a 6-week timeline. Start permits and 811 early, and schedule right after a dry spell, not during one: you want the contractor to see the water problem, but you want them digging in workable soil.
Figures current as of October 2026. Sources: HomeGuide and Angi 2026 cost data, contractor-published pricing guides.