Miguel Landscaping

Professional landscaping and hardscaping in the San Fernando Valley. From retaining walls to full property transformations — quality craftsm...
Winnetka, US
Created byProfile picturedeftbending
1 joined
Profile picture
@deftbendingProfile pictureMay 13
Pinned post

Why most retaining walls fail (and how to build one that lasts 20+ years)

I've built over 200 retaining walls across the San Fernando Valley. The #1 reason walls crack and lean? Bad drainage.


Most contractors skip the gravel backfill and weep holes. It saves them half a day of work. But when the first heavy rain hits, hydrostatic pressure builds up behind the wall and it starts pushing outward. Within 2-3 years, you've got a leaning wall and an erosion problem worse than what you started with.


Here's what a proper retaining wall needs:


Foundation: Minimum 6" compacted gravel base below grade. The bigger the wall, the deeper you go.


Drainage: 4" perforated pipe at the base wrapped in filter fabric, with clean gravel backfill at least 12" behind the wall. This is non-negotiable.


Batter: A slight lean-back into the hillside (about 1" per foot of height). Gravity becomes your friend instead of your enemy.


Materials matter: Interlocking concrete blocks for walls under 4ft. Anything taller needs an engineered design with rebar and concrete.


If you're in the SFV area and want a retaining wall done right — or need a second opinion on one that's already showing problems — reach out. Free consultations, always.