Timeline for Paying Contractors

[Caleb Smith]

I am currently working on my first BRRRR deal and recently received an estimate from a general contractor I plan to work with.

For payment, he stated he needs approximately 25% of the overall estimate upfront as a down payment to order materials and said that should last for the 1st two weeks.

Is that normally how this works, or am I only supposed to pay each week for the work that was done that specific week?

I'm sure there are many different ways payments are handled between investors and contractors, but just wanted to see how other people handle the situation.