Practicalities on a hempcrete build - The Hempcrete Topic: Designing and Building with Hemp-lime - page 445

Waterproofs or knee pads help to minimize lime burns in
wet weather.
In serious rain, put a halt to mixing and placing work, unless your mixer is under cover
and you can arrange things such that the sections of wall being cast are filled from inside,
so that workers are not getting drenched.
Risk of freezing
The temperature is always a factor when placing hempcrete, for the same reasons as with
any lime-based product, including (although to a lesser extent) ordinary Portland cement.
What you are trying to avoid is the temperature dropping to below 0°C before the binder
has had a chance to react chemically with the water (hydrate) to achieve its initial set.
At around -1°C, some of the water in the mix will begin to freeze, slowing down the speed
of the hydration reaction. At around -3°C or -4°C, enough of the water freezes that hy-
dration stops completely and, depending on the extent of hydration and the corresponding
strength of the material, the force of the water changing state (ice typically occupies around
9 per cent more space than water) is a risk to the long-term integrity of the setting material.