signed lien waivers from all subcontractors

[Louis Van Der Westhuizen]

Hello BP

I'm interested in knowing if and how you go about obtaining signed lien waivers from subcontractors when you do flips? Where do you get the waiver, does the general contractor and the subcontractors sign it, should you include this at the time of closing the master contract? And how do you ensure that the GC discloses any and all subcontractors they plan to use (this may often be an unplanned issue so how do you stay in the loop to ensure every sub signs the waiver)?