FORMULA SHELF 1 of 370

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Workshop 1 formulas

Ground fall and drainage falls

fall % = (rise / run) x 100 ; a 1 in 80 floor falls 12.5 mm a metre

SYMBOLS · 1 in 60 to 1 in 100 for a yard or a path; 1 in 40 to 1 in 60 for a yard slope; floors are level, the water goes to the drain

UNITS · %

HOW TO USE

Water on a level yard is water that never leaves. Get the fall right with a laser level or a long spirit level and a pegged board. See Underground Pipe And Trenches.

EXAMPLE

A 20 m yard falling 1 in 80 drops 250 mm from end to end.

fall slope drainage level yard

SOURCES & PROVENANCE 1 listed

This page is an AI-organised index. The label means the grouping and cross-links were compiled with AI; the information itself comes from the public-domain books, reports and manuals listed below. Open any source to read the local copy or follow the link to the original publication.

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Formulas collected and indexed with AI. The calculators are convenience tools; double-check every result before using it.