02
Behind the Walls
THE CONDITIONS WE EXPECT TO FIND BEHIND THE WALLS
When we walk an older home, we're not guessing. We're reading the age of the house and naming the usual suspects out loud, so you hear them before the contract, not during demo. Here's most of the list.
Dated Electrical: Knob-and-Tube and Panels at Capacity. Two electrical conditions show up over and over in older Bay Area homes.
The first is knob-and-tube wiring, the original system in a lot of pre-war and mid-century houses. It's not automatically dangerous if it was left alone, but it has no ground, insurers increasingly won't touch it, and the moment you open a wall near it for a remodel, inspectors often want it gone. That turns a cosmetic job into a rewiring job.
The second is the panel. Plenty of homes from the 1960s and 70s run a 100-amp service where 200 amps is the modern standard, and that panel was frequently at capacity before anyone thought about adding a kitchen island, a heat pump, or an EV charger. Relocate an appliance or add a circuit and you can trip straight into a service upgrade you didn't plan for. We see this constantly: a kitchen remodel that turns into kitchen plus electrical because the panel had nothing left to give.
Aging Plumbing: Galvanized Supply and Cast-Iron Drains. Plumbing in a vintage house ages where you can't watch it.
Galvanized steel supply lines corrode from the inside. The pipe looks fine from the outside right up until water pressure drops or a joint lets go inside a wall. Cast-iron drain lines have a long life, but "long" isn't "forever," and a 60-year-old drain that's outlived its useful run is a real possibility, not a worst case. Open one wall for a bathroom and you can find both. That's how a tile job turns into a partial re-pipe.
Water Damage and Dry Rot Behind Finishes. This one hides better than any of the others.
Tile in an older bathroom is often the only thing holding back a slow water problem. Grout and caulk fail over 20 or 30 years, water migrates behind the tile plane into the framing and the subfloor, and nothing shows on the surface until you pull it. A cosmetic tile replacement becomes a subfloor replacement, and sometimes framing repair. The homeowners who aren't blindsided by that aren't lucky. They were told about it during assessment, so they were prepared.
Foundation, Soil, and Seismic Reality. Then there's everything below and behind the structure.
Bay Area lots come with their own complications: expansive clay soil that swells and shrinks with the seasons, sloped yards, mature tree roots, drainage that was never really engineered. A foundation that's served fine for decades can still need attention once you start adding load or opening walls. And in earthquake country, a remodel is often the moment to handle seismic conditions a mid-century house was never built for, like a cripple wall that was never braced or a structure never bolted to its foundation. None of that is a reason not to renovate. It's a reason to know the ground you're standing on before you commit.
Asbestos, Lead, and the Stuff Code Forgot. Last, the materials that were ordinary then and regulated now. Homes from this era can carry asbestos in old flooring, popcorn ceilings, and pipe wrap, and lead in original paint. Disturbing them during demo triggers handling requirements that cost time and money. It's the kind of thing you want named in the plan, not discovered with a saw in your hand.
