Paying contractor 20% after the house is sold.

[Rao V.]

Hi,

So I have a contractor who is willing to take the last 20% payment after the house is sold. 80% or so will paid weekly on milestone basis. The project will take appx 6-7 weeks max. 

The situation is that I have a house under contract and I can only arrange 80% of the bid and that's why I asked him can he wait till the house is sold. He agreed as we both know it is a hot area and house will sell in a month.

And even if house does not sell by that time I will have additional 20% as well. My question is what should be putting in contract incase things go sideways. What should I be concerned about. liens? etc.

Thanks in advance