This guide is a continuation of our article, Ordering & Installing GCL Pond Liners: Five Essentials to Lock-In Before the Truck Arrives. If you’ve already unrolled the liner, this Part 2 covers what happens next — and how to avoid costly mistakes during the final phase before burial.
Laying a GCL is only half the job — and what happens in the hours and days after installation can make or break the liner’s performance. The bentonite core needs the right environment to seal up tight. Follow these tips to avoid common pitfalls during the critical handover phase.
1 | Cover the GCL Within 72 Hours
GCLs are designed to be buried — not left exposed. Within 48 to 72 hours of installation, get the GCL covered with compacted soil, ballast, or overlying layers (e.g. geomembrane if part of a composite). Prolonged exposure to sun, wind or dry air can desiccate the bentonite before it hydrates, reducing swell potential and seam integrity. Cover-as-you-go is best — finish one area before starting the next.
2 | Keep Rain Off Before Burial
If the liner hydrates before being covered, you’re in trouble. Uncontrolled hydration causes uneven swelling that can lift seams and shift overlaps. If rain is forecast and the liner isn’t yet buried, lay down tarps or polyethylene sheets. If the GCL gets soaked, inspect the area before proceeding — you may need to trim and replace affected sections or reapply bentonite at seams.
3 | No Foot or Machine Traffic
Until it’s covered, the liner is vulnerable. Avoid walking or driving over exposed GCL. Foot pressure can displace overlaps, and wheels can crush or tear the fabric. If access is unavoidable, lay down wide timber boards or track mats to spread the load. Always remove any loose soil, fill, or debris before final burial.
4 | Inspect the Seams Daily
Even if the liner looks fine after install, wind and weather can shift seams overnight. Check all overlaps for alignment and cleanliness — and ensure the transverse joints are still correctly covered. If wind has lifted a panel, re-seat the overlap and reapply bentonite powder or paste as needed. Better to catch it early than come back later with an excavator.
5 | Maintain Slope Anchors
Slopes present a risk of liner slippage — especially if cover placement is delayed. Use anchor trenches or mechanical fixings at the crest and toe of each slope, and check daily for signs of liner creep. If working on a steep or soft subgrade, reduce panel length to avoid shear movement.
6 | Watch for Contamination
Keep bentonite away from fuels, oils, or reactive chemicals. Contamination can weaken the clay’s sealing properties and prevent proper swelling. Never install GCL over materials like lime, cement-treated subgrade, or frozen ground unless confirmed compatible.
7 | Dried-Out Panels? Don’t Reuse Blindly
If a GCL panel has been installed, pre-hydrated, then dried out before cover — don’t assume it’s still good. Bentonite performance drops after drying and rehydration cycles. For high-risk containment applications, the safer call is to replace the panel.
Final Tip
Once buried, GCLs are extremely durable and require no maintenance. But during that short post-installation window, the right care can make or break their long-term performance.
