If the builder can't work because of rain and stays idle for 7 days, should he claim the rental fee of scaffolding and tower crane from the owner?

Under normal circumstances, it is impossible.

1, because when you bid, you should consider natural conditions such as winter and rainy season, and you should formulate corresponding measures and take them into account in the tender offer. In other words, the comprehensive quotation contains risk factors.

2. Special circumstances can claim compensation, such as floods caused by heavy rains, which are force majeure. However, it must be supported by relevant evidence and conform to the contract. Otherwise, claims are often not approved.