TODAY I MET outside the south wall with Brian James, who works for a stucco repair contractor. He has 17 years of experience in dealing with aging and decrepit stucco surfaces in the L.A. area. While awaiting his bid for restoration, I will write up what I learned from our conversation.…
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Executive Summary
Major surgery is indicated: Half of the wall’s stucco should be replaced altogether, and meanwhile a way for moisture to get out of the wall needs to be provided. Assuming that lead in the old paint is not an issue, the work would take about 2 months to complete. Four other contractors would need to be involved, as well.
Diagnosis
Brian claimed to be familiar with older walls built in our region in the manner of this one. It is not uncommon that there is no way for the moisture that’s trapped by the tar paper (interior vapor barrier) to get out (i.e., no weep screed), and no waterproofing on the outside of the foundation wall. Consequently, the inside of the wall is bound to become damp, except to the extent that its outer surface manages to keep moisture from getting inside in the first place. (That is, if the paint is not refreshed and if the expansion cracks that develop in the surface are not sealed, then the outer surface will be compromised.)
Stucco does not last forever; after 40 years, it starts to get weaker. Exposed south-facing walls are always the ones in the worst condition. Ours is no exception. The exposed half of our wall is starting to disintegrate, as indicated by soft spots; it has reached the end of its useful life. In contrast, the western half of the wall has a couple of decades more of life; its cracks can be sealed and then it can be repainted.
Prescription
Top section, eastern half: Replace the stucco.
Top section, western half: Repair cracks and prep for painting.
Where frame wall meets foundation wall: Remove an 8"-wide horizontal strip of stucco, and install flashing that enables moisture to escape.
Foundation wall: Remove loose stucco, apply new stucco. The finish coat covers both the old and the new spots.
The work would take about 2 months to complete. (Applying the new stucco itself takes about a month, because of the drying time that’s required between coats.)
Related Issues
1. As part of granting a building permit, the City will determine whether the content of lead in the underlying paint requires that a certified lead abatement contractor must be used, instead of a regular stucco-repair contractor.
2. Remove the 3 eastern windows temporarily, so that they are not damaged while the stucco is being replaced.
3. Any structural wood that has been softened or rotted by exposure to moisture may break apart to some extent as the stucco is removed. To repair that wood, a framing contractor must be called in, before the stucco replacement can proceed. There is no way to predict how much wood will need to be replaced, or how much that effort will cost.
4. Stucco work will get the outer wall surface to paint-ready condition. Then that work should be followed immediately by painting the surface. The painting contractor could use the stucco contractor's scaffolding.
5. A waterproofing contractor must be called in to seal the joint between the bottom of the wall and the asphalt pavement.
Prognosis
Going forward, the inevitable expansion cracks in the surface will need to be regularly sealed, and the paint will need to be kept refreshed.
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