Roof Rainwater Drainage Calculations

Upon completion a full set of rainwater drainage design calculations are provided confirming the suitability of products.

Roof rainwater drainage calculations.

The calculations below are meant for drainage from flat roofs where water are expected to spread over the entire flat roof during rain. Mep work provides free excel calculator for drainage calculation of roof rainwater and storm water. We describe online roof drainage requirements calculators pertinent plumbing standards a table approach to looking up roof drainage. The number of roof drains shown should be verified with local code requirements.

Roof drainage requirements specifications. The tools guide the user step by step allowing fast and simple roof drainage design whilst ensuring full compliance with bs en12056 3 rainwater drainage design standard. Nds quickly identifies drainage problems and selects the right solution to resolve issues at home. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table.

The roof drainage outlets and rainwater downpipes are calculated based on the design principles for gravity drainage systems established in ss525 2006 code of practice for drainage of roofs. The above sizing data is offered as a guide only. Box gutter with rain water head at end of box gutter. The roof drain calculator below is based on the maximum amount of rainfall in inches per hour of the hypothetical worst storm in the past 100 years and which has a two percent chance of occurring in any given year.

Take the roof s total square footage and divide by the total square footage handled by one drain. The speed at which the rain collects at the drain. Use this rainwater harvesting calculator to find the answer. A simple rain catchment system can provide water for outdoor use resulting in.

Calculate drains needed. Download free calculation excel sheet for the design of drainage systems for roof rainwater and storm water these calculation spreadsheets calculate the quantity of rainwater and the sizing of gutter rainwater. Three spreadsheet for free download with direct links. The new nds app is the perfect tool for determining runoff and system requirements on the go.

Wondering how much rainwater you could collect off your roof. The result is the number of drains needed. Calculate your drainage install on site. Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments.

This article describes several methods for determining the drainage capacity required to safely drain water off of building roofs whether from rainfall melting snow or a combination of those water sources. How to calculate roof runoff.