French Drain vs. Interior Drain Tile: Which Do You Need?
Where each system works best and when to combine them.
Both systems channel water away from your foundation, but they solve different problems. French drains intercept surface and shallow groundwater outside the home. Interior drain tile catches water that's already reached the footing. Many homes need both.
When a French drain is the right call
If water pools in your yard, runs toward the house during storms, or saturates the soil within 5 feet of the foundation, a French drain ($25–$50 per linear foot installed) intercepts it before it reaches the basement walls. Best paired with proper grading and downspout extensions.
French drains require an exit point — daylight, a dry well, or a storm sewer connection. Without somewhere for water to go, they simply become an underground swimming pool.
When you need interior drain tile
Interior systems handle water that's already getting through the foundation — seepage at the floor-wall joint, hydrostatic pressure pushing through hairline cracks, or groundwater pushing up through the slab. They cost $40–$80 per linear foot installed and require breaking up the perimeter slab.
Interior drain tile manages water; it doesn't stop it. If aesthetics in a finished basement matter and budget allows, address the source from outside first.