Century-old buildings that were never meant to be sealed
The streets around Malaga Cove Plaza hold some of the earliest planned architecture in Palos Verdes Estates, laid out in the nineteen twenties in a Spanish Colonial Revival idiom that the community has preserved carefully ever since. The materials are original in a great many of these homes: lime plaster, clay tile roofs, timber framing, and thick wall assemblies with no cavity at all.
Those materials behave in a way modern ones do not. Traditional plaster is permeable by design. It takes on moisture and gives it back, and a wall built that way stays healthy as long as it can dry in both directions. Problems start when somebody, usually with good intentions, seals one face of it.
The most common cause we find here is a modern repair
Cement render patched over lime plaster. Modern impermeable paint on an exterior that used to breathe. Spray foam added into a roof space that was designed to be ventilated. Each of those is a sensible-sounding upgrade, and each traps moisture inside an assembly that has spent a century relying on being able to release it.
The damage does not appear where the repair was made. It appears at the edge of it, where the sealed area meets the unsealed area and the moisture that can no longer escape through the front is pushed sideways.
Other findings that recur on these blocks:
- Clay tile roofs with failed underlayment. The tile outlives the felt beneath it by decades. Tiles look immaculate while water has been passing them for years.
- Original steel casement windows. Cold frames in a marine climate condense heavily, and the water runs into the plaster reveal below.
- Deep eaves and shaded elevations. North-facing walls under wide overhangs on a canyon lot get very little direct sun and stay damp far longer after fog.
- Canyon-side lots. Marine air settles and lingers in the canyons rather than moving through, so ambient humidity beside them runs higher than a hundred yards away.
Inspecting a historic house without damaging it
Everything we do is non-destructive. Moisture meters read through finishes without cutting them. Thermal imaging finds temperature differences behind plaster, which on solid wall construction is the only practical way to see what is happening inside it. Where a wall cavity has been created by later work, that shows up too, because the thermal pattern changes at its edge.
Air sampling, where readings justify it, is measured against a same-day outdoor control. Surface sampling identifies what is present. Nothing needs opening up for either, and given how tightly change is controlled in this community that is a practical necessity rather than a courtesy.
Independent by design
Golden State Mold Inspections does not perform remediation. On a century-old house that separation is worth a great deal, because the aggressive interventions a remediation firm can sell are frequently the exact thing that caused the problem in the first place. Our recommendations are as often about removing a previous sealant as adding anything, and we have no commercial reason to prefer one over the other.
Questions from Malaga Cove owners
The house is nearly a hundred years old. Is damp just part of that?
A degree of seasonal movement in moisture readings is normal in traditional construction and is not a defect. Sustained wet readings, growth, or a smell that does not clear are not normal at any age. The inspection distinguishes the two.
We want to reduce humidity. Should we seal and insulate?
Not without knowing how the walls are built. Sealing a permeable wall is the most reliable way to create a problem that did not exist. Where insulation is appropriate there are breathable ways to do it, and that decision should follow the readings rather than lead them.
Do you handle the architectural review requirements?
No, that sits with you and your architect. What we provide is documentation of the actual condition, which is generally what a review process wants to see before approving any change to a historic elevation.
Our roof tiles look perfect. Can the roof still be the source?
Yes, and it frequently is. The tile is a rain screen, not the waterproof layer. The felt underneath does that job and it has a far shorter life. Perfect tiles above failed underlayment is one of the most common patterns on these streets.
Homes of this period frequently carry two other materials worth identifying before any work starts. Asbestos testing before any renovation and lead paint testing for homes built before 1978 are both commonly requested here. See also every area we serve along the coast.
Getting to us from Malaga Cove Plaza
From Malaga Cove Plaza, take Palos Verdes Drive West north, continue onto Palos Verdes Boulevard, then turn left onto Pacific Coast Highway and follow it north. Turn left onto Rosecrans Avenue, right onto Sepulveda Boulevard, left onto Grand Avenue and left onto Lomita Street. Our office is at 204 Lomita Street, El Segundo, CA 90245. Call (310) 525-0619.