80 year old house leaking from lack of ledger flashing.

Hello, Kindly give me advice regarding rain water leaking through one 18'x 20' stucco wall weather side,abutting a second floor patio. The water drips down to the first major outside beam in the room underneath the patio. The inside of the beam is fine. The outside part of the beam actually is the border to the outside of the patio. As it rains the beam is saturated with water all the way to the right hand side to the outside corner of the room. Rain seems to fully saturate the beam halfway to the middle of the room in two or three places. The stucco facade is facing due West and it is always leaking when it rains,and buckets usually fill up a quarter during very windy rainstorms with the wind & rain blowing into the west facing stucco wall. The patio is covered totally with Karnak all weather roof cement. This large leak has supposedly been going on for over 50 years. How should one approach waterproofing the stucco. The stucco wall has original layers of oil and latex paint on it. During a recent rainstorm while shining high powered light against the wall, one could see many yellow lines where water is seeping through. From the outside painted side stucco wall one only sees a few cracks. It seems there are many fine cracks in the original stucco, but how can one inexpensively waterproof this stucco wall? Hypothetically,could one place the all weather Karnak tar roof cement over the entire stucco wall as a first coat, then flashing material over the entire surface, and then add a second coat of the more rubbery oil & tar Leak Stopper product? I am looking to solve this major leak without a mayor expense. Can Thuroseal or Xypex be at all effective with this problem with unknown old stucco material? Kindly,advise me as to your suggestions. I live in Jamaica/Briarwood, Queens County/Long Island part of New York City.

Your stucco is leaking from a lack of ledger flashing. Either there is no ledger flashing, or the old steel flashing has rusted out.

Ledger board flashing

No need to go to the extreme by putting waterproofing on the whole wall.

An example of the ledger board flashing. The reason for the double ledger boards was the idea of the carpenters. The original ledger board had rotted out and needed to be replaced. One and a half inches was cut off the deck boards to allow space for the old board to be removed. An additional ledger board fills the space. A good idea if your ledger board has rotted out.

Cutting and patching stucco

Bad picture, but I hope you can see what is going on. Stucco is cut off a few inches, new tarpaper and lath, and stucco patched back.

Water will penetrate stucco, even painted stucco. This is alright provided there is a flashing at the bottom to keep water froom running behind the wall.

This will work. Thanks for visiting my site.