What foundation drain means
A foundation drain is a perforated pipe or gravel drain installed outside the footing during construction to carry groundwater away from the foundation.
Also called footing drain.
Where it matters on a waterproofing job
Old clay or clogged foundation drains are a common cause of wet basements. Exterior excavation to replace them is the most thorough fix and the most expensive; give it as one option next to interior drainage.
What the model code says
- Drain tiles, gravel or crushed stone drains, perforated pipe or other approved systems are installed at or below the top of the footing. (IRC 2021, Chapter 4)
Check which code edition your building department enforces for foundation drain before you quote.
What it costs
For foundation drain, the closest koira.ai price is the basement waterproofing cost guide, near $5,000 for a typical job and $2,450 to $8,200 for most. The guide shows its sources and what moves the price.
Work it out
- Cost guide: Basement waterproofing cost
- Tools, templates and guides: Free waterproofing resources
Sources: 2021 International Residential Code, Chapter 4, Foundations (ICC). Checked October 9, 2026.