NC Pipe has numerous options for your precast storm manhole and junction box needs. Precast concrete structures are offered in round (48" thru 72" Dia.), square (3'x3' thru 12'x12') and rectangular (all sizes) configurations. Custom Precast structures can be provided per job specifications with thru holes or knockouts to accommodate all styles/sizes of pipe and box culvert at all required elevations, drops and angle entries.
Standard base sections with four-sided knockouts are in inventory and ready for prompt pickup or shipment. Sizes available: (All Dimensions are ID):
Custom bases are produced per project requirements. Many jurisdictions require a minimum size or shape of manhole. Please check with your project specifications and regulations