Pipes, Drainage & Ducting
GeoPipe™ - Slotted HDPE Subsoil Drainage Pipe
Slotted double-wall HDPE subsoil drainage pipe, 75, 110 and 160 mm OD. 6 m lengths with 270° slots or 50 m coils with 360° slots. For French drains, agriculture, sports fields and foundation drainage across South Africa and Africa. Larger collectors to 315 mm: GeoPipe HD.
Overview
GeoPipe Slotted HDPE Subsoil Drainage Pipe
GeoPipe collects groundwater through slots in a corrugated double-wall HDPE pipe. Its low-weight construction simplifies handling, while the inner waterway supports drainage to a designed outlet. It is supplied for French drains, road edge drains, sports turf, agricultural land drainage, foundation perimeters and retaining-wall back-drains across South Africa and African project markets.
The standard slotted range is 75, 110 and 160 mm outside diameter, with typical internal diameters of 60 (±1), 90 and 137 mm. Specify 6 m straight lengths with 270° slots or 50 m coils with 360° slots. Straight-length nominal slot width is 2.0 mm; coil slot widths are 1.3, 1.3 and 1.8 mm respectively. Larger collector pipes in 200, 250 and 315 mm are addressed by GeoPipe HD, subject to the specified slot configuration.
Buried conduit compression performance is referenced to SANS 61386-24: straight lengths ≥450 N and coils ≥250 N at 5% internal-diameter deformation, with Class N impact classification. This is not an SN ring-stiffness rating or approval for a particular burial depth or traffic load.
Standard drainage pipe is black. Red is available on request for telecom cable ducting - select solid, unslotted GeoDuct for cable protection. Slotted pipe is intended to admit water and must not be substituted for a sealed cable conduit.
Select a filter aggregate and geotextile compatible with the site soil and hydraulic design. GeoPipe FS provides an integrated filter-sock option, with filtration suitability assessed for the project. An appropriate gradient, outlet, access for maintenance and protection against sediment entry remain necessary. Do not assume a sock alone prevents clogging in every soil.
Install to the approved bedding, cover and backfill design. Orient the unslotted invert of 270° pipe correctly using the product marking; 360° slotted coils collect around the circumference. Keep coil bends at or above 15 times OD. Check joints, slot orientation, line and level, filter continuity and outlet condition before backfilling.
Geosynthetics Africa coordinates supply, accessories, delivery, installation support and agreed QA/QC documentation. Send diameter, metres, straight or coil format, filter requirements and delivery location for projects in South Africa, Southern, East, West and Central Africa.
- MaterialHDPE
- StructureSlotted double-wall corrugated subsoil drainage pipe
- ColourBlack standard; red telecom ducting on request via GeoDuct
- StandardSANS 61386-24; Class N impact; ≥450 N straight / ≥250 N coils
- Roll WidthOD75, 110 and 160 mm; typical ID60 (±1), 90 and 137 mm
- Roll Length6 m straight lengths (270° slots); 50 m coils (360° slots)
Typical Properties
| Property | Test Method | Unit | Typical Value |
|---|---|---|---|
| Outside / typical inside diameter | Dimensional check | mm | 75/60 (±1) | 110/90 | 160/137 |
| Straight format | Supply | m / degrees | 6 m lengths; 270° slots |
| Coil format | Supply | m / degrees | 50 m coils; 360° slots |
| Nominal slot width | Dimensions | mm | Straight: 2.0; coils: 1.3 | 1.3 | 1.8 (OD75 | 110 | 160) |
| Compression resistance | SANS 61386-24 | N | Straight ≥450; coils ≥250 at 5% ID deformation |
| Colour / larger sizes | Ordering | - | Black drainage pipe; GeoPipe HD collectors to OD315 |
Note: The above values are typical and not intended for specification purposes. Please refer to the product datasheet for full details.
Typical Applications
View all applicationsRoad & Rail Formation Drainage
Intercept groundwater beside roads, railway formations and platforms using a designed network of standard laterals and GeoPipe HD collectors. Select diameter, stiffness, cover, filters and outlet spacing from the pavement drainage and loading design.
Retaining Walls & MSE Back-Drains
Collect water at the base of retaining walls, MSE structures and basements through a designed drainage layer and pipe system. Select the filter for the actual backfill; provide accessible outlets and maintenance points.
Mining Underdrain & TSF Drainage
Use engineered slotted collection systems for seepage beneath mine platforms, TSFs or containment works only after checking load, hydraulic capacity and compatibility with the actual fluids. GeoPipe HD collectors extend to 315 mm; project-specific engineering governs selection.
Sports Fields & Landscaping
Use slotted laterals and collectors to manage groundwater beneath turf, golf courses and landscaped areas. Set pipe spacing, depth and gradient from soil permeability and required drainage rate; select coil or straight formats for installation access.
Agricultural & Farmland Drainage
Manage waterlogging using designed field laterals feeding collector mains and an approved outlet. Specify filtration from soil grading and clogging risk. Standard drainage coils are 50 m in 75-160 mm; HD collectors are available to 315 mm.
Compatible Systems
View all systemsGeoPipe 75 & 110 mm - Standard Drainage
75 and 110 mm OD standard slotted pipe for French drains, foundation perimeters, field laterals and landscape drainage. Choose 6 m lengths with 270° slots or 50 m coils with 360° slots. Typical IDs 60 (±1) and 90 mm. Filter selection and loading must suit the design.
GeoPipe™ DN160 - Normal Duty Collector
160 mm OD standard drainage pipe with typical 137 mm ID. Standard formats are 50 m coils with 360° slots or 6 m lengths with 270° slots. Use hydraulic design to size collector lines and define gradients, filters and outlets.
GeoPipe HD™ DN200 - Heavy Duty Collector
200 mm OD / typical 173 mm ID in 6 m lengths. SN8 base pipe to SANS 21138-3; 120° partial or 360° full slots with project-specified dimensions. Confirm finished slotted performance and burial design.
GeoPipe HD™ DN250 - Heavy Duty Collector
250 mm OD / typical 217 mm ID in 6 m lengths for designed collector systems. SN8 base pipe to SANS 21138-3; choose 120° partial or 360° full slots. Chemical compatibility must be checked for mining or landfill fluid collection.
GeoPipe HD™ DN315 - Primary Main
315 mm OD / typical 273 mm ID in 6 m lengths for larger collector and gravity drainage duties. Specify slotted collection or solid-wall conveyance, joint and seal requirements. Cover, backfill, loading and capacity require engineering review.
Installation Guidance
Standard Method Statement
Excavate to the engineered depth, width and gradient. Select bedding and flexible-pipe support for the pipe, soil, groundwater and loading. Refer to the project specification and applicable buried-pipeline requirements, including SANS 10102-2 and SANS 2001-DP1 where specified.
Verify diameter, configuration and condition before laying. Orient partially slotted pipe using the product marking with the solid invert below: standard 270° lengths and HD 120° crown slots differ. Fully slotted coils or lengths collect around the circumference. Maintain coil bend radius of at least 15 × OD and inspect joint engagement.
Install compatible filter aggregate and geotextile or the specified sock arrangement. Filter selection must match soil and hydraulic requirements. Provide uniform side support and protect pipe and filtration layers against displacement or damage during backfill.
Backfill and compact to the approved sequence and cover before plant access. Verify gradient, outlet, inspection and flushing access. Record material identification, slot pattern, line and level, joints, filters, bedding and cover as the installation QA/QC record.
Quality Assurance & Testing
Field QA/QC Checklist
- Delivery & Storage: Materials checked against the delivery note and conformance certificates, stored off the ground, covered from UV and kept clear of sharp objects and fuel.
- Material Conformance: Pipe certificates checked for diameter, ring stiffness and perforation pattern against the specification.
- Trench & Bedding: Trench excavated to line and grade; bedding and filter material placed as designed (geotextile wrap or sock where specified).
- Laying & Joints: Pipe laid to the design fall with couplers fitted; perforations oriented as specified.
- Backfill & Flushing: Backfilled with the specified drainage aggregate; outlets and rodding points installed and the line flushed or CCTV-inspected where required.
Manufacturing Standards
- Manufacturer pipe specification and certificates
- Project drainage specification
- SANS 61386-24; Class N impact; ≥450 N straight / ≥250 N coils
Documents
Product Selection Guide
Compare performance properties across the entire category hierarchy before specifying.
Installation & Method Statement
Standard deployment procedures, installation specifications, and field application method statements.
QA/QC Site Checklist
Field quality control procedures, inspection checklists, and testing standards to verify installation integrity.
Technical Data Sheet (TDS)
Guaranteed minimum average roll values (MARV) and material testing properties.
Chemical Resistance / Accessories Guide
Chemical compatibility matrix and list of auxiliary materials needed for installation.
Projects Using GeoPipe™ - Slotted HDPE Subsoil Drainage Pipe
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