To reduce this time, additional moisturizing the surface is necessary. Since the substance inside the cylinder is unstable, and chemical reactions are difficult to control, the shelf life of such a foam is very short. In professional construction, structural foam. It includes two chemical isolated substances. They react only when the foam is activated. The time of hardening and hardening is much less. Such a foam cannot be used again, so it is used in the performance of large -scale work.