How structural drying actually works on a Christchurch build

Step 1 — Map the moisture

Before any equipment goes in, we map the affected area with thermal imaging and moisture meters. This tells us how far moisture has travelled — often well beyond the visible wet patch — and sets the baseline readings we'll dry back from.

Step 2 — Extract the bulk water

Every litre of free water we physically remove is a litre we don't have to evaporate. Standing water is pumped or vacuum-extracted first, which is far faster and cheaper than drying it out of the air.

Step 3 — Dehumidify and move air

This is the core of structural drying. Air movers sweep high-velocity air across wet surfaces to drive evaporation, lifting moisture into the air; dehumidifiers then pull that moisture back out. The two work as a pair — roughly three to four air movers per dehumidifier.

In a Canterbury winter, refrigerant dehumidifiers lose efficiency below about 15°C, so we switch to or add desiccant units, which absorb moisture chemically and keep drying in the cold.

Step 4 — Add heat, carefully

Warm air holds and carries more moisture — every ~10°C increase roughly doubles the evaporation rate. We add heat in balance with dehumidifier capacity. Too much heat without enough dehumidification just moves moisture around; the right balance dries the structure evenly without cupping timber or peeling paint.

Step 5 — Monitor and verify

Data loggers record temperature and humidity continuously while meters track material moisture daily. When every monitored point hits target — framing ≤ 18% MC, ambient below ~50% RH — we issue the completion report and your next trade is clear to start.