When HDPE is specified on mega civil works
HDPE geomembrane provides a welded, low-permeability barrier for reservoirs, canals, cofferdams, and containment ponds where fluid loss and long-term chemical resistance matter. Petroseal HDPE geomembrane has been supplied on Pakistan's largest hydropower and dam packages—including Suki Kinari Hydropower Project and Diamer Bhasha Dam civil works—alongside geotextile separation and drainage layers coordinated with major contractors.
HDPE is stiffer than LLDPE and suits engineered subgrades with compaction control. Field crews extrusion-weld panels into a continuous liner; seam testing is non-negotiable on WAPDA-scale projects.
Build-up with geotextile and drainage
Non-woven geotextile cushions HDPE from puncture on rocky or angular subgrades—typically minimum 300 g/m² on aggressive foundations per consultant detail. Geotextile also separates dissimilar soils and provides filtration in toe drainage blankets.
Geogrid may appear in approach embankments and platforms adjacent to lined zones—composite designs should be staged so installation crews do not puncture completed liner areas during fill placement.
| Component | Function |
|---|---|
| Compacted subgrade | Smooth, tested surface |
| Geotextile cushion | Puncture protection |
| HDPE geomembrane | Primary barrier |
| Cover soil / riprap | Ballast and UV shield where exposed |
Thickness and weld QA
1.5–2.0mm HDPE is common on exposed canal and dam-related lining; final thickness follows hydraulic head, subgrade risk, and design life. Trial welds at start of each shift, destructive tests on coupons where specified, and air-pressure testing of seams per project protocol.
Coordination with slope systems
HDPE geocell on dam faces and spillway shoulders works in staged packages with liner and geotextile—see our geocell application note for cell depth and infill selection. For farm-scale ponds with uneven settlement, LLDPE may be preferable; HDPE remains the default on engineered hydraulic structures.
Contact Petroseal at 0321 8489737 for geomembrane submittals and reference project discussions.