The invention relates to a method of internally coating a pipe comprising the steps of; drying the pipe by a flow-through of dehumidified, compressed air followed by; cleaning said pipe by pumping a mixture of compressed air and particles of an abrasive material through the pipe and; possibly blowing compressed air at a controlled flow together with a liquid silane based polymer coating material into the pipe so that a coating layer is applied onto the interior walls of the pipe, and allowing the polymer coating material to self-cure at ambient temperature. The method is useful for internally coating a pipe or a system of pipes such as a gutter pipe, a rain pipe, a sewage pipe, a hot water pipe, a cold water pipe, a drain pipe, a portable water pipe, a natural gas pipe, and a fire sprinkler system pipe. By means of the inventive method non-toxic internal coating of a pipe is achieved according to construction industries requirements as regards use of non-toxic substances.
