Method and elevator arrangement

A method in the manufacture of an elevator, comprising the steps of:

• installing a movable, supporting platform and an elevator car in an elevator hoistway;
• performing a rope installation wherein the elevator is reeved to comprise construction-time hoisting roping, and the construction-time hoisting roping is arranged to support the elevator car from the supporting platform supported above the elevator car;
• taking the elevator car into use to serve passengers and/or to transport goods;
• removing the elevator car from use;
• changing a service range of the elevator car to reach higher up in the elevator hoistway by lifting the supporting platform higher up in the elevator hoistway;
• and
• taking the elevator car back into use,
• wherein, in the rope installation, the construction-time roping comprises one or more ropes, a longitudinal power transmission capability of which is based essentially on non-metallic fibers in a longitudinal direction of the rope,
• wherein, in the method, the supporting platform is lifted taking a vertical support force from guide rails of the elevator that extend to above the supporting platform, wherein at least most of the vertical support force needed for lifting is taken from the guide rails,
• wherein, before the lifting of the supporting platform, a first support arrangement is supported on a top most surface of a top end of a guide rail section of a first guide rail line of the guide rails on a side of the elevator car and a second support arrangement is supported on a top most surface of a top end of a guide rail section of a second guide rail line of the guide rails on an opposite side of the elevator car, which top ends extend essentially to above the supporting platform, and, in the lifting of the supporting, the supporting platform is pulled with first and second hoists associated with the first and second support arrangements, respectively, to higher up in the elevator hoistway taking the vertical support force needed for the lifting from the guide rails with the first and second support arrangements,
• wherein the first and second support arrangements are provided separately so as to not be directly connected to each other, and
• wherein the first and second hoists extend only to the first and second support arrangements, respectively.