A Process is described for lining the inner surfaces of pipes or pipe sections using the Insituform method by pressing a tubular flexible laminate made up of an essentially liquid-impermeable membrane and a fibrous layer which has been impregnated with a binder which is not as yet fully cured with the face with the binder against the inner surface of the pipe by means of liquid pressure in such a way that the laminate takes on the shape of the inner surface of the pipe and the binder becomes fully cured in the state, forming a firmly adhering internal lining. The binder used according to the invention in this process contains(a) a curing agent which is a salt of one or more (poly)amines having at least one tertiary nitrogen atom and one or more aromtic polyols or one or more aliphatically substituted phenols, the aliphatic radical having at least 9 carbon atoms, and(b) a liquid epoxy resin or a liquid mixture of epoxy resins and can, if desired, also contain(c) further additives.The process according to the invention is suitable, for example, for lining the inner surfaces of sewers and of gas and water mains.