[nimblemotors]

I have a house built in 1950 with a stucco exterior. Where the electrical box attaches there was water leakage into the interior wall and the studs and lap board have rotted away, along with all the waterproofing paper.

Replacing the studs is straightforward, but what about the lap boards?
And what I am stumped about is how to restore the waterproofing that the original tar paper provided.
I'm thinking I can just use the bathroom waterproofing brush-on sealant (redguard) on the bare stucco on the inside.
But I haven't seen any discussion of this in all my searches.

I don't have pics just yet, but will post them in the next few days.
The good news is this is a gable wall that isn't really load bearing,
and the studs don't even tough the base plate anymore anyway.

 

[Ron6519]

The last time I had the issue on a customers house, the stucco came off and I built it up from the inside out. The area was re-stuccoed and matched to the rest of the house..

 

[nimblemotors]

The last time I had the issue on a customers house, the stucco came off and I built it up from the inside out. The area was re-stuccoed and matched to the rest of the house..

That is what I've read people doing. I don't want to do this because it is a relatively small area, and the stucco has the power wires from the pole attached there into the main breaker box. I'll have to get the city involved to cut off the power, and NOTHING IS WORSE than dealing with them.

 

[nimblemotors]

Here is the picture of my wall rot. The water was coming in where the wires come in from the breaker box, over 65 years rotted the 2 studs. So not a big area, tearing out all the existing stucco not really an option.

 

[Oso954]

So not a big area, tearing out all the existing stucco not really an option.

To do the job right, it's the only option.

It's also a permit job, and you may be required to structurally upgrade it, rather than replace it in kind.
You also need to insulate that wall to current standards.

I would suggest you contact your building dept and discuss the requirements before proceeding further.