Soakaway Sizer

What it does

Planning conditions and Building Control ask for a soakaway designed to BRE Digest 365 — and the calculation usually means a spreadsheet at your desk, a web tool that charges per report, or a consultant. Soakaway Sizer runs the full method on your phone, offline, next to the trial pit: enter the percolation test, the drained area and the design rainfall, and it sweeps every storm duration, takes the worst case as the digest requires, and shows every step of the working so the design can be checked and defended.

Features

• Percolation test — pit dimensions and timed 75%-to-25% falls with a live infiltration rate, the lowest of your runs governing; or enter a rate you already have
• Full storm sweep — the 1-in-10-year storm across the whole duration range, largest required storage governs, with the governing storm identified
• Two-way sizing — enter dimensions and check compliance, or fix length and depth and let it solve the width per storm, the digest's own procedure
• Compliance, line by line — half drain-down within 24 h, distance to buildings, groundwater and ground-condition checks as clear pass/fail badges
• Shows the working — the I − O = S table for every storm, exportable as text for the job file
• Private by design — no account, no ads, no tracking, no network use at all; everything works offline in the field

Soakaway Sizer is a design aid: it does not replace the judgement of a competent person, and every design should be verified by one before construction. Rainfall values are your own working from the digest's method and data; the app does not supply them. Calculations follow BRE Digest 365 (Revised 2016); the app is not certified, approved or endorsed by BRE.