Not every drain-lining project is a Railway tender (see our dedicated GCCM for Railway Drains (LHS) page if yours is). Stormwater drains, factory/industrial site drains, agricultural field drains, and general earthen channel lining all face the same core problem: unlined drains erode, silt up, and lose capacity over time, while cast concrete lining is slow, costly, and often impractical for long or irregular drain runs.

nKrete GCCM and its lighter-weight variant used for earthen drain lining, often specified in tenders as Concrete Canvas / concrete-impregnated fabric (CC-5), 5 mm thickness gives contractors a genuine “concrete-in-a-roll” alternative for exactly this kind of work.

Why GCCM for General Drain Lining

  • ✅ Faster than cast concrete — no shuttering, no batching plant, no lengthy cure-and-strip cycle
  • ✅ Consistent, controlled thickness — factory-manufactured to a specified thickness (from lighter 5 mm CC-5 style linings for earthen drains up to the standard nKrete range for higher-duty applications), avoiding the inconsistency of hand-poured concrete
  • ✅ Conforms to the drain’s actual shape rather than requiring the drain to be reshaped to fit standard concrete forms
  • ✅ Reduces water loss and erosion along the drain length once hydrated and cured
  • ✅ Simple lap-and-overlap installation is typically installed with a 100 mm overlap between consecutive sections, with the overlap included in the measurement per standard practice

Choosing the Right Thickness/Product for Your Drain

  • Earthen field/agricultural drains, lighter-duty lining: the 5 mm CC-5-style concrete-impregnated fabric is typically specified as cost-effective for lower-flow, lower-traffic drain lining
  • Higher-duty stormwater, industrial, or infrastructure drains: the standard nKrete range (9 mm and above) is typically specified where greater strength, compressive load, and long-term durability are required
  • Railway line-side, catch water, or side drains: see our dedicated GCCM for Railway Drains (LHS) page, which covers the specific EN/ASTM specifications typically required in Railway tenders
  • Canal-scale drainage works: see GCCM for Canal Lining

If your drain sits alongside a slope or embankment that also needs erosion protection, see GCCM for Slope & Soil Erosion Control. Where subsurface water is the issue rather than surface drainage, our Geo Drain Tube composite drainage system is the right product instead.

Installation Overview

  1. Surface preparation, earth excavation/profiling of the drain to the approved cross-section, soil profiling, and dressing
  2. Roll-out of the GCCM/concrete canvas fabric along the drain, with 100 mm overlap between sections
  3. Fixing, pegging, and anchoring as required for the site
  4. Hydration and curing into a hard, durable, waterproof lining
  5. Backfilling and surface finishing to complete the works

FAQs

Q: What’s the difference between standard nKrete and the 5 mm CC-5 product mentioned in tenders? A: Both are Geosynthetic Cementitious Composite Mats (GCCM) — the 5 mm version is a lighter-duty concrete-impregnated fabric typically specified for earthen drain lining, while standard nKrete (9 mm and above) is specified for higher-duty applications requiring greater strength and durability.

Q: Is GCCM suitable for agricultural field drains as well as engineered stormwater drains?

A: Yes — GCCM’s flexibility and range of thicknesses make it suitable across both lower-duty agricultural/earthen drain lining and higher-duty engineered stormwater and industrial drainage works.

Q: How is overlap between GCCM rolls handled during installation and billing?

A: Standard practice is a 100 mm overlap between consecutive mat sections, with the overlap quantity included in the measured area for payment consistent across both standard nKrete and CC-5 style applications.