Professional Wall Services
Drainage behind the wall in Nanaimo
Essential backfill drainage systems designed to eliminate water pressure behind retaining walls.
Nanaimo Retaining Walls installs sub-surface drainage behind the wall across 8 Vancouver Island communities. We lay perforated drain tile, filter fabric, and clean crushed rock behind every wall build. You get a written quote after our free site visit to assess your slope drainage needs.
Preventing hydrostatic water pressure
Hydrostatic pressure is the primary cause of retaining wall tilting, cracking, and eventual failure. Water trapped behind a wall multiplies soil weight, pushing the wall face forward. You can review all material pricing options in our complete cost guide.
Drain tile and crushed rock installation
We place continuous perforated drain pipe wrapped in filter fabric along the heel of the footing trench. The space behind the wall is filled with clear, angular crushed gravel to create a free-draining zone. We also provide retaining wall repair and replacement for damaged structures.
Geotextile fabric separation
To keep soil fines from clogging the drain rock layer over time, we line the backfill zone with geotextile filter fabric. This fabric allows groundwater to pass through while holding back dirt and clay. We also build concrete block retaining walls with full drainage systems.
Drainage system options
Sub-surface drain tile systems
Perforated piping and filter fabric envelopes installed along the heel of the footing.
Clear stone backfill layers
Angular aggregate backfill zones designed for high-volume groundwater drainage behind walls.
How we install wall drainage
- 1
trench lining — line rear trench wall with heavy geotextile filter fabric
- 2
pipe placement — lay perforated drain tile along heel of wall footing
- 3
rock backfilling — place clear crushed stone backfill behind wall courses
- 4
fabric wrap — fold filter fabric over top gravel layer before soil cover
Local permit and building requirements
Permits are mandatory for walls over 1.2 metres in Nanaimo, Qualicum Beach, Ladysmith, and Duncan, or 1.2 m or higher in Parksville.
People also ask
Why is crushed rock used behind retaining walls?
Angular crushed stone creates open voids that allow groundwater to drain rapidly away from the wall face.
What is a weep hole in a concrete wall?
A weep hole is a small pipe passing through the wall face to discharge trapped water from the backfill rock layer.
How much does wall drainage installation cost?
Drainage installation is priced as part of a complete wall build or repair estimate following a site visit.
Can I add drainage to an existing wall?
Yes, we can excavate behind an existing leaning wall to install fresh drain tile and clear rock backfill.
You might also want retaining wall repair and replacement and concrete block retaining walls, or see what these usually cost in the cost guide.
Service areas across the region
More on retaining walls
- Retaining wall cost guideCompare prices per square foot across our five priced wall construction materials.
- Retaining wall repair and replacementRestoring leaning wall faces and replacing collapsed retaining structures.
- Concrete block retaining wallsHeavy pre-cast block units stacked on level footings to create clean terraced yards.
- Nanaimo Retaining Walls home
Ready for a quote on retaining walls in Nanaimo?
We provide free on-site quotes.