Good Evening,

I am a professional Landscape Designer/Contractor (24 years) who needs tutoring on the requirements for water-proofing exterior stucco walls on a residence built in the 1920's in Northern California. I have advised my client that her residence needs 'flashing' installed, but I am unfamiliar with what other products are connected to this process. My instinct tells me that a trench of 18" depth should be dug along the house exterior, to a width of 12", but beyond that, I am at a loss. My expertise lies in every other aspect of landscaping a site, but my knowledge is weak in this area. The existing structure looks pretty solid to me, but who knows what we may find below grade?

Any guidance would be greatly appreciated!

Thank you much.

Earthtender

Earthtender:
Whay does she need "flashing" and what do you mean by it? And out of curiosty, why are you the one telling her this (since your expertise is landscaping)?

Usually flashing is a top covering that deflects water. I have a feeling you mean water-proofing the foundation.

If so, what is the foundation? The stucco will likely only go to grade, not below. Is there water in the basement? Is there a basement?

If not, and she is getting leaks in the house, she might be better off going to a stucco company or even an architect for an assessment. An architect will be able to take a whole-picture look at things and make recommendations. (fees would not be excessive for this phase and may well save money and problems down the road).

Actually, as an architect, I would appreciate it (if I were in this situation) if you also contacted me, since you probably have a better understanding of the issues than the owner, since you are bringing it up. The best solutions are found in teamwork.

Good luck.

You are correct, you do need flashing installed right at the sill/bottem plate usually the plate is pressure treated, what I presume is missing from the original stucco installation what is called a weep screed which is a nail on strip of angled metal flashing with or without holes in it,  that became a code requirement in the 1960's the weep screed allowes the moisture to escape from the stucco. The residence you are describing, the stucco goes right to the dirt, which means you will always have a moisture problem and the stucco will blister and eventually fall off. Trenching away from the wall is a good idea, do not let the stucco come in contact with the dirt. installing the weep screed flashing at this stage would be unwise, for the reason thay you would have to saw cut around the perimeter of the residence. you will cut the support wire, the wire that holds the stucco together plus you would undermine the vapor barrior, in addition it would be very difficult to match the existing texure, my advise is leave it be.  Water proofing is a waste of time. remove the dirt away from the stucco.

Sincerely

J R