Test Before You Demolish: Pre-1978 Mountain View Homes

Census figures put more than half of Mountain View’s housing before 1980, and about a third of it in the 1950s and 1960s. That makes this a straightforwardly relevant topic here rather than an edge case: most bathroom remodels in this city happen in houses old enough to warrant testing.

The cost asymmetry is what makes it an easy decision. Testing runs $300 to $800. Abatement, if something is found, runs $1,500 to $8,000 and adds one to three weeks. Both of those are manageable numbers when they appear in a budget before work starts. Neither is manageable when demolition stops on a Tuesday and nobody can go back in.

Where asbestos turns up in a bathroom

Not in dramatic places. The common ones are unglamorous:

• Sheet vinyl flooring, especially the backing, and the mastic underneath it. This is the single most common find in a bathroom of this vintage.
• Vinyl floor tiles, particularly nine-inch squares, which are almost a period marker.
• Joint compound and textured finishes on walls and ceilings.
• Pipe insulation, where any survives on an old line.
• Occasionally cement board products behind tile.

Note what these have in common: they are all things that get broken up, scraped or sanded during a bathroom demolition. Undisturbed, none of them presents much of a problem. The exposure comes from the demolition itself, which is exactly the moment nobody wants to discover them.

Lead

Lead in paint was permitted in housing until 1978. In a bathroom it matters mostly for window trim, door casings and any painted surface that gets sanded or heat-stripped during the work.

Contractors performing renovation for compensation in pre-1978 housing operate under the federal Renovation, Repair and Painting rule, which sets out training, containment and cleanup requirements. The EPA’s lead pages cover the detail. For a homeowner the practical consequence is simply that a firm working in older housing should already be set up for this, and that it is a fair question to ask.

How testing works

A sample is taken from each suspect material, usually a small piece cut or scraped from an inconspicuous spot, and sent to a laboratory. Results normally come back within a few days, sometimes next day for a premium. Lead can also be screened on site with an XRF instrument.

The efficient approach is to test everything suspect at once rather than one material at a time, because most of the cost is in the visit and the minimum lab fee rather than in each individual sample. A bathroom typically means three to six samples: flooring, mastic, joint compound, and whatever else looks like a candidate.

Timing matters. Testing is most useful after the room is emptied but before anything is broken up, which in practice means arranging it during the design and permit window rather than the week demolition is due to start. Results in hand before the schedule is set is the whole point.

What happens if something comes back positive

Less drama than people expect. Asbestos-containing flooring and mastic in a bathroom is a routine abatement: a licensed contractor isolates the room, removes the material under controlled conditions, and clears it. It costs money and it takes time, and then the project continues normally.

The scenarios that damage a project are the other ones. Demolition already underway when the material is identified, meaning an uncontrolled disturbance and a much more involved cleanup. Or, worse, nobody identifies it at all and the material simply goes out in a skip along with the dust it produced.

The other pre-1978 finding

While testing is happening, it is worth establishing what the supply lines are made of. Galvanised steel pipe was standard in this era and corrodes internally over decades. If it is still in service, replacing it while the walls are open is the cheapest opportunity the house will get, and it belongs in the same conversation as everything else on this page: a known cost in the budget rather than a discovery in week three.

None of this is a reason to be nervous about remodeling an older house. Half this city is an older house. It is a reason to spend a few hundred dollars in the quiet part of the project, so the loud part stays on schedule.

More on what else these houses tend to have in store in a third of Mountain View was built in twenty years, and on the schedule implications in the timeline guide.