One component glue:
adhesive made from a mixture of isocyanates, reacting with sprayed water and moisture contained in the air. If used for the bonding of one or more porous surfaces, it is sufficient that only one of the two surfaces requiring gluing is porous, e.g. porous-porous and porous-compact).
This type of glue is particularly susceptible to outside temperature and humidity and it is recommended to use it in both environments at controlled temperatures between 18°C and 30°C and environments with a relative humidity (RH) between 40% and 60%.