HIFLOW DRAINAGE CELL Drainage cell
HDPE dimpled drainage sheet with bonded non-woven geotextile filter
Dimpled drainage cell with a bonded geotextile filter that relieves water pressure at the membrane face.
HIFLOW DRAINAGE CELL sizes and key figures
HDPE dimpled drainage sheet bonded to a non-woven geotextile, laid over a cured membrane. It gives a drained cavity behind walls and under green roofs, podium decks and planter boxes.
What is a drainage cell?
A drainage cell is a dimpled plastic sheet with a filter fabric bonded to one face. It stands off the membrane, the fabric keeps soil out, and water runs down the dimples to the drain instead of pressing on the membrane.
- Roll size
- 15 × 1.5 m22.5 m² per roll, 37 kg · TDS p2
- Thickness
- 15 mmtypicalnominal, ISO 9863-1, white HDPE with geotextile face · TDS p2
- Flow rate
- > 150 L/min/mtypicalASTM D4716, i = 1.0 under 100 kPa · TDS p2
- Compressive
- 250 kPatypicalASTM D6364. Do not exceed in service · TDS p2
- Heat resistance
- 70°Ctypicalfor 1.5 hours · TDS p2
- Install at
- +5°C to +40°Ctypicalambient · TDS p2
- Lap allowance
- Approx. 10%typicalof gross roll area, deduct on every side and end · TDS p2
- Take-off
- Area + 20%typicalmeasured area, for laps and wastage · TDS p2
From the FORSPEC data sheet, TDS-HIFLOW · Revision 2 · 12 November 2026. Times are at 25°C and 50% relative humidity unless the data sheet says otherwise. Typical = FORSPEC’s own typical value, not a laboratory-certified one.
HIFLOW DRAINAGE CELL on site
More FORSPEC jobs
Where HIFLOW DRAINAGE CELL is used
Use it for
- Retaining walls and basement walls
- Planter boxes and landscaped areas
- Green roofs and roof gardens
- Podium decks
- Underground car parks
- Protection layer over FORSPEC membranes during backfill
Know before you start
- Not a waterproofing membrane: it drains and protects only
- Never over an uncured or untested membrane
- Must discharge to a working drainage line, or it becomes a reservoir
- Not a structural layer or a substitute for engineered subsoil drainage
How to apply HIFLOW DRAINAGE CELL
- 01
Prepare
The FORSPEC membrane must be fully cured, flood tested where required and signed off. Clean the surface and clear debris and any sharp or protruding objects.
- 02
Check outlet
Confirm the drainage outlet or discharge point is installed, connected and free flowing, and that the falls to it are correct.
- 03
Lay
Cut to length. Unroll with the geotextile face towards the soil or growing medium and the dimpled core against the membrane.
- 04
Fix
Fix only above the waterproofing termination line, never through the membrane. Lap sheets in the direction of flow and secure the lap.
- 05
Close laps
Carry the geotextile across every lap so no open joint is left for fines. Cut neatly around penetrations and dress the geotextile over the opening.
- 06
Backfill
Inspect for displacement, open laps, punctures and blocked outlets. Then place and compact backfill in controlled layers so the cell is not crushed or torn.
A short guide from the data sheet. Read the full HIFLOW DRAINAGE CELL TDS before you start.
Learn to install it
Hands-on FORSPEC training that covers HIFLOW DRAINAGE CELL.
Drawings for the systems it goes in
FORSPEC standard details as PDF and DXF. Each sheet is a generic detail: the specification names the products.
HIFLOW DRAINAGE CELL test reports and compliance
- ASTM D4716 flow rate
- > 150 L/min/m, typical R&D valueFORSPEC R&D
- ASTM D6364 compressive strength
- 250 kPa, typical R&D valueFORSPEC R&D
Results as stated in the data sheet, TDS-HIFLOW · Revision 2 · 12 November 2026. Warranty up to 25 years, depending on the system: ask FORSPEC which term applies to your system.
HIFLOW DRAINAGE CELL questions
How big is a roll of HIFLOW Drainage Cell?
15 m × 1.5 m, which is 22.5 m² and 37 kg. Allow about 10% for laps and about 10% for wastage. The TDS take-off basis is measured area plus 20%.
Which way round does it go?
Geotextile face towards the retained soil or growing medium, dimpled core against the membrane. Fitted the wrong way round, the cavity blinds with fines.
Can I fix it through the membrane?
No. Fix only above the waterproofing termination line and never penetrate the membrane.
Does it waterproof?
No. It drains and protects. The waterproofing is done by the FORSPEC membrane beneath it, which must be cured, flood tested and signed off before the cell goes on.
Where does the water go?
To a working drainage line. A drainage cell with no outlet becomes a reservoir against the structure, so confirm the outlet is connected and free flowing before backfill.
Used with HIFLOW DRAINAGE CELL
HIFLOW DRAINAGE CELL data sheet
Always work from the current data sheet. Every FORSPEC TDS and SDS →
Specify it. Or buy it.
Send the drawings or photos and FORSPEC comes back with the system, the details and the quantities. Or find a FORSPEC stockist for HIFLOW DRAINAGE CELL.