Veneer stone install question

I’m doing an investigation for a client that had water coming into his basement from under the front door entrance. Basically the concrete stoop had negative slope and water was penetrating the osb rim joist due to a lack of sufficient flashing and what I believe is the 2 layers of underlayment for the stone veneer not extending far enough below the sill plate. I would think that a few inches is sufficient. In this case it was about even. What is sufficient?? Also, the manufacturer doesn’t specify a weep screed even if the veneer touches grade. Any thoughts???

Thanks,

Vince

Do you have pictures?

What is above the area?

If the area under the stoop is full the water has to go somewhere.