Gabion retaining wall engineering is the design discipline that turns a stone-filled wire basket into a structural product. Walls under 1.2 m for landscape edging or decorative low-profile retain don't typically need engineering; walls ≥1.2 m, walls supporting structures or surcharge loads, and walls in public-realm work do.
Base preparation — the foundation is everything. Strip vegetation and topsoil down to native subgrade. Place a 200–400 mm compacted granular base; in cohesive soils with bearing-capacity concerns, an engineered base course may need geogrid reinforcement. The base must be level and properly compacted to 95% Modified Proctor.
Geotextile — separates the retained soil from the wall fill stone, preventing soil migration into the gabion voids over time. Non-woven needle-punched geotextile is the standard, 200–300 g/m² mass. Place on the back face of the gabion and wrap up over the top course for the first 600 mm of wall depth.
Drainage — water in the retained soil generates hydrostatic pressure that overturns walls. Standard detail: 100 mm perforated drain pipe at the base behind the wall, surrounded by clear free-draining stone, geotextile-wrapped, daylighted to surface or stormwater system. Weep holes through the wall every 1–2 m help where below-grade drainage isn't practical.
Fill spec — stone size must be larger than the mesh opening to prevent loss through the wires. For 100 × 100 mm welded mesh, fill stone 150–250 mm; for 100 × 80 mm twisted hexagonal, fill stone 120–200 mm. Angular quarry-run is engineering-default; decorative river rock, slate, or recycled material works for visible architectural walls.
Batter angle — rear lean of approximately 6° from vertical. Easier to plumb in the field if you set posts at 6° rear lean as a guide.
Welded vs twisted mesh — welded mesh gives crisp architectural appearance, PVC coating for coastal exposure. Twisted hexagonal mesh conforms to ground better, accommodates differential settlement, and is the engineering substrate for retaining walls supporting roadway or structural loads.
Stamped engineering drawings are part of our standard delivery for commercial gabion orders ≥1.2 m wall height.
Frequently asked questions
Related guides
Frost-depth fence post installation: Canada city by city
Frost-depth fence post installation guide for Canadian cities — Toronto 120 cm, Montreal 140 cm, Edmonton 180 cm, Vancouver 60 cm, Winnipeg 180 cm, plus 14 more. Posts set above local frost line heave by the third winter cycle; concrete footings must extend to or below frost depth. Pre-mixed gravel-and-concrete sleeves outperform plain concrete in freeze-thaw zones. Related: [browse all materials](/fences), [start a quote](/quote), [more guides](/guides).
→Fence cost in Canada 2026: per linear foot, every material
Canadian fence cost ranges $4.50/ft (farm woven-wire) to $240/ft (frameless glass pool), installed. Per-linear-foot pricing is more honest than per-panel because gates, end-posts, footings to frost depth, and existing-fence removal aren't panel-priced. Regional variation matters — Atlantic salt-spray, prairie frost, BC mild climate, and Quebec pool regulation all shift pricing. Related: [browse all fence categories](/fences), [start a quote](/quote), [more buying guides](/guides).
→Quebec 2025 pool fence regulation: compliance guide
Complete guide to Quebec's 2025 pool fence regulation: 1.2 m minimum height measured outside, self-closing self-latching gate, no climbable surface within 1 m, picket spacing ≤100 mm. Applies to every residential pool ≥60 cm depth. Compliance window is 60 days from installation. Frameless glass and aluminum picket are the compliant material defaults. Related: [pool fence regulations across Canada](/guides/pool-fence-regulations-canada), [start a quote](/quote), [browse pool fence](/fences/pool-glass).
→One quote. Every material. Every province.
Tell us material, project size, postal code, and contact — we come back within 24 hours with pricing, lead time, and a local install or delivery slot.