Our specialty. A French drain only works if it is deep enough to intercept groundwater before it reaches your foundation or crawl space — on Bay Area hillside lots that usually means a trench in the 3.0–3.8 ft range, not the shallow line many budget quotes describe. We bed perforated pipe in washed drain rock, wrap the trench in filter fabric so fines stay out, and discharge through solid pipe to a safe outlet.
What’s included
- Trench excavation to the design depth for your slope and soil
- Perforated pipe bedded in washed 3/4-inch drain rock
- Filter fabric wrapping to keep silt and fines out of the rock
- Cleanouts at key points so the system can be inspected and flushed
- Solid-pipe conveyance to a safe discharge point
- Backfill, compaction and surface restoration
- Haul-off of excavated soil (not piled on your property)
Typical timeline
Most residential French drains take about 2–5 working days depending on length, depth and equipment access.
Common questions
How deep should a French drain be?
Deep enough to sit below the level you are protecting and still hold a drainage slope to the outlet. For hillside homes that commonly means 3 ft or deeper — a shallow trench may catch surface water but miss the groundwater that actually reaches foundations.
Will a French drain fix water in my crawl space?
Often it is a key part of the fix, because it intercepts water before it arrives. The right answer depends on where the water is coming from, which is exactly what the free site visit is for.
Every project starts with a free site visit and a written, itemized proposal. Call (520) 858-9998 or use the estimate form — we serve the San Francisco Bay Area.