Drainage geocomposite calculator
Behind a retaining or basement wall, or across a slab or slope: the composite to order and the collector pipe at the foot.
Free access for engineers and buyers
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Results appear here as you type.
How the calculation works
Behind a wall the composite covers wall length × the height to be drained; on a slab or slope it covers the area. Overlap and wastage are added, and a wall gets a collector pipe along its full length at the foot. Example: a 60 m wall drained over 4 m needs 252 m² with 5% overlap and 60 m of pipe.
Planning quantities for budgeting and enquiry. A Retech engineer confirms the grade and quantity against your drawings before order.