Where Is Asbestos in Old St. Louis Houses? A Job-by-Job Check

Where is asbestos in an old St. Louis house?

It most often hides in six places: floor tile and the black glue under it, wrap on pipes and furnaces, textured ceilings and patching compound, siding and roofing shingles, pour-in attic insulation, and door gaskets on old stoves and furnaces. The EPA lists these. None of them are visible as asbestos. A lab has to say so.

Our guide to asbestos in older St. Louis homes lists materials room by room. This post takes a different path. It starts from the job you plan to do and tells you which material that job can disturb. That is the order that matters, because the EPA says fibers are released by “the disturbance of asbestos-containing material during product use, demolition work, building or home maintenance, repair, and remodeling.”

How old are St. Louis houses, really?

Most are old enough to worry about. Census data for 2024 show that 152,091 of 174,694 housing units in St. Louis city, about 87%, were built before 1980. In St. Louis County, 301,975 of 447,542 units, about 67%, were built before 1980. The city also has 98,061 units, about 56%, built in 1939 or earlier.

Do not read “pre-1940” as “safe.” Missouri DNR says asbestos “was used in a number of different materials” until the 1970s. A brick house from the 1920s may still have a furnace, flooring, siding or patching added in a 1950s to 1970s update. The year built tells you where to look. It does not clear a house.

Which repair or remodel will disturb which material?

Match your project to the materials in the table below. If the job is in the right-hand column, test before you start.

Note what the table leaves out: a closed, dry, untouched material. The EPA says exposure generally happens only when asbestos-containing material is disturbed or damaged. An intact floor under carpet is a different risk from a floor you are about to grind.

What can I check myself without touching anything?

You can look, take photos and write notes. You cannot sample. The EPA says “Taking samples yourself is not recommended,” and that sampling done wrong can be more hazardous than leaving the material alone. Use this no-touch walk-through.

1. Write down the year built and every remodel you know of. Ask the seller, the previous owner or a neighbor.
2. Start in the basement. Photograph pipe wrap, boiler or furnace jackets, and the furnace door gasket.
3. Look at each one for what the EPA names as damage: tears, abrasions and water damage.
4. Check floors under carpet at a vent opening or doorway where the edge is already exposed. Photograph it. Do not pry or cut.
5. Look at ceilings for sprayed or textured coatings, and note any water stains.
6. In the attic, look from the hatch only. If you see gray-brown or silver-gold pebbles, treat them as vermiculite and stay out.
7. Walk the outside. Note siding and roofing type, and any cracked or broken pieces.
8. List the jobs you plan in the next two years, then mark which ones touch a material above.

Bring the notes and photos to the inspector. They shorten the visit and make the sample plan sharper.

Which of these materials is the biggest worry?

It depends on the form. Hard cement products are the lowest risk until someone cuts them. The CPSC says asbestos cement roofing, shingles and siding “are not likely to release asbestos fibers unless sawed, drilled, or cut” (the CPSC page prints “dilled”). Sprayed, wrapped or crumbly material is the opposite case.

The CPSC also notes that “Houses built between 1930 and 1950 may have asbestos as insulation.” That fits St. Louis, where 56% of city units were built in 1939 or earlier. Its advice before a remodel is plain: “Before you have your house remodeled, find out whether asbestos materials are present.”

What about vermiculite in the attic?

Treat it as asbestos and leave it alone. The EPA says a mine near Libby, Montana, was the source of over 70 percent of all vermiculite sold in the United States from 1919 to 1990, and that this vermiculite was contaminated with asbestos and often sold as Zonolite. Our vermiculite attic insulation page covers removal. For this post, the point is simple: an attic that holds loose pebbles is not a place to run wiring, store boxes or let children play.

When is damage a reason to act now?

Act soon when material is torn, crumbling, wet or rubbed by daily traffic. The EPA says damaged material may release fibers, especially if you often disturb it by hitting, rubbing or handling it. Pipe wrap in a walkway, a worn furnace gasket and water-stained ceiling texture are the usual cases.

Friable material crumbles by hand pressure when dry, such as boiler insulation or paper pipe insulation, according to Missouri DNR. Non-friable material, such as floor tile, is bound in a hard product. Friable material in poor shape is the urgent case. Intact non-friable material can wait for your remodel, but it should be tested before the work.

How do I confirm what I have?

Hire a certified inspector to sample and send the samples to a lab. The result tells you which materials contain asbestos, where they are, and what condition they are in. Our asbestos testing and asbestos survey pages explain what you get. AES staff include AHERA Certified Building Inspectors, and Mr. Ruckman is trained and certified as an Asbestos Inspector and Supervisor.

Once you know, you have three choices: leave it, seal it, or remove it. The testing guide for older St. Louis homes walks through that decision. Material-specific pages cover floor tile, siding, pipe insulation and popcorn ceilings. Work above Missouri’s thresholds needs a registered contractor, covered in our asbestos abatement service.

Next step

If you plan to remodel an older St. Louis home, test the materials the job will touch before you start. Call Advanced Environmental Services at (314) 865-2662 or use our contact page to ask about asbestos testing. Do not remove or cut anything while you wait.