Home Improvement--General/Ext. Stucco Patching


QUESTION: Hi- The hole in an ext. stucco wall (opened for a plumbing repair to drain pipe) measures about 1 ft. X 2. ft. It's on a ground floor wall. I have not patched stucco before, but as I had read some about "how To" the paper, the wire, then the layers of stucco, it struck me that maybe the expanding spray foam I'd used to close some smaller gaps around the repaired pipe, might be used to fill all around the repaired pipe, and hole, building it's thickness until it reaches a depth of where the actual stucco would start. Will stucco stick to the foam once it fully drys? Am I out of my mind for even considering this approach? By the way I rate my skills at intermediate, am I in over my head altogether. Thank You FFor Your Time... Dean

ANSWER: Dean- No you are not over your head at all. Go for it. As to the foam-the stucco will not stick to it very well. Nor can foam be used to rely on anything structural. So no major hole or void should try to be completely filled without some sort of backing. Then, as long as your wire mesh is mechanically fastened to structure-stucco away!
Good luck and feel free to contact me for any reason.

---------- FOLLOW-UP ----------

QUESTION: Glen, Thanks for your earlier very timely and encouraging response. I'm afraid I still have yet another question.

I have looked at my garage, (it's walls are open,) and I find the layers are this: studs, black paper, stucco. No wood between interior and ext. and I've tried to figure the vapor, vs moisture barrier conundrum. I can't, I live in Ca. if that matters... so here's the essence. Should I use a 1/4"  2" X 24" inch piece of ply, and attach this to the studs as a backer for the lath. Where dos the black paper then go? Do I need paper for such a small hole? I don't remember there being any paper present when the plumber opened it. It seemed there was stucco, then wire, then insulation, then the inside of my house LOL.

Or... do I attach the paper, then the lath to just the studs, then start stuccoing? I've asked at the home center, but they look at me like I'm speaking in a foreign tongue so I'm very grateful for your help. Dean

Hmm...If I am reading this right you should install the mesh first(from the exterior), then paper from the interior that is sealed-silicone is fine. Just lap the existing paper by 3". Any moisture barrier is better than none. Even in CA. than stucco away!
Contact me for any reason Dean.

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Glen W


I can answer almost any question about residential construction / renovation


I have worked as a General Contractor for 25 yrs. in 10 states.

BA in Architecture

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