This is a question we get asked a lot. The scenario is pretty common. The floor will be screeded and then shortly after equipment such as an EWP will need to work on the floor to install the ceiling or lights or similar.
The answer is that "it depends". It depends on the screed, the equipment, how the equipment is used and moved and what steps are taken to protect the screed.
Heavy equipment such as EWPs are heavy and have a very high point loading on their small wheels. The wheels also turn very tightly transmitting both a lot of weight and twisting force into the screed. This can often result in cracked screed or surface damage to the screed.
However, if the screed is an engineered screed (stronger than a traditional screed) and has been allowed time to cure and gain strength (full strength is typically after 28 days but significant strength is gained after the first 14 days) and if the screed is protected by timber boards which spread the load of the wheels, then EWPs and similar may be able to operate successfully over the screed. There is unfortunately no one single answer.
If the EWP work needs to be scheduled for after the screed installation (as opposed to prior to the screed going down), our best advice is to leave the screed as long as possible to cure and protect the screed as best as possible.
If however, the screed is damaged by the heavy equipment, then we recommend that the damaged areas be repaired prior to further works such as tiling or the installation of waterproofing or other flooring products being carried out over the screed.