Mould Growth Index
Is mould likely to be starting on a given surface, and when would it become visible? A 0–6 daily index from the published VTT mould growth model (Hukka & Viitanen 1999; Ojanen et al. 2010), joining 30 days of humidity/temperature history to a 7-day forecast, for a chosen material sensitivity class.
37 days — 30 past, 7 forecast
The index on a 0–6 axis over six labelled bands. The solid line is the continuous run from 30 days of history; it lightens at today's vertical rule where the forecast begins. The dashed line is what the index would be if this surface were clean today. Hover or focus any point for that day's humidity, temperature and growth status.
Why it moved — humidity vs. critical humidity
The index only grows when relative humidity is at or above the critical threshold for this material and temperature (the dashed line). Bars above the line are growth-favourable days; bars below are drying days.