A method for providing a seal in an annular space between a rehabilitative pipe liner and a conduit wall is provided. Areas on the surface of a section of a conduit wall surrounding lateral connections are provided with an expandable sealing agent, preferably during an investigative and/or cleaning inspection of the conduit section and preferably without repeated withdrawal and insertion of equipment between the provision of the agent at successive lateral connections. The rehabilitative pipe liner is then installed in the conduit section and a curing agent or agents such as heat, visible light, ultraviolet light, chemical agents, sonic energy or other radiant energy means is applied to cure or form the rehabilitative pipe liner and to cause the expandable sealing agent to expand and fill at least a portion of the annular space that may exist between the rehabilitative pipe liner and the conduit wall.