How Much Weed Membrane Do I Need?
Quick Answer
Ground area + 150mm overlap at joins. Standard roll: 1m or 2m wide
Based on: Total coverage area with 150mm minimum overlap between adjacent strips
How to Calculate
Measure the area to be covered, then work out how many strips you need based on the roll width. Add 150mm overlap per join.
- Area: e.g. 6m × 4m = 24m²
- Using 2m-wide rolls across 4m width: 2 strips needed
- Each strip: 6m long
- Total membrane: 2 × 6m = 12 linear metres, plus 150mm overlap
- Total: 12.15 linear metres of 2m-wide membrane
Standard Roll Sizes
- 1m × 15m: 15m² coverage — ideal for borders and paths
- 1m × 25m: 25m² coverage
- 2m × 25m: 50m² coverage — best for larger areas
- 4.5m × 100m: 450m² coverage — trade/commercial rolls
Types of Weed Membrane
- Woven polypropylene: Most common for domestic use. Good drainage, reasonable lifespan.
- Non-woven geotextile: Better filtration, used under driveways and paths.
- Heavy-duty (100gsm+): For driveways, parking areas, and commercial use.
- Biodegradable: Breaks down over 2–3 years. Only for temporary weed suppression.
Installation Tips
- Clear all existing weeds and level the ground before laying
- Overlap strips by at least 150mm to prevent weed growth at joins
- Secure with metal U-pins every 300–500mm along edges and joins
- Cover with gravel, bark, or aggregate — UV will degrade exposed membrane
Last updated: April 2026