The Delaware Valley Regional Planning Commission (DVRPC) documents that more than 57% of all housing units in Delaware County were built before 1960 — a higher concentration of old housing than the broader Delaware Valley region. The Delaware County Health Department estimates that 80% of county homes are likely to contain lead-based paint, and documents over 300 children poisoned by lead annually.
These numbers aren’t abstract. They reflect the physical reality of the housing stock in Chester, Upper Darby, Lansdowne, Darby, Sharon Hill, Collingdale, Folcroft, and Ridley Park — and what a homeowner in any of those communities is statistically likely to be dealing with.
Why Construction Year Is the Most Reliable Predictor
Asbestos use in American residential construction followed a clear arc:
- Pre-1930: Asbestos increasingly used in industrial and commercial construction; limited in residential
- 1930–1945: Widespread introduction of asbestos into residential building materials — pipe insulation, floor tiles, roofing, plaster
- 1945–1970: Peak residential use — 9×9 floor tiles nearly universal, acoustic ceiling tiles standard, duct insulation common in postwar forced-air systems
- 1970–1980: Declining use as health concerns mount; EPA bans on specific products begin
- Post-1980: EPA banned spray-applied asbestos (1973), asbestos pipe wrap for residential use (1975), and asbestos-containing patching compounds (1977). Production of asbestos floor tiles effectively ended in the early 1980s.
A home built or renovated between 1940 and 1980 is the primary risk window. More than half of Delaware County’s housing stock falls within this window.
What 57% Pre-1960 Actually Means on the Ground
The DVRPC figure is a county-wide average. In the older boroughs closest to Chester, the concentration is significantly higher:
Chester: The vast majority of residential housing predates 1950. Brick row homes built 1900–1940 dominate.
Upper Darby: Median year built approximately 1952. Dense brick row homes and twins from the 1920s–1950s make up most of the housing stock.
Lansdowne: Median year built approximately 1939. Victorian and Craftsman-era housing developed primarily 1890–1930 is the norm.
Darby: Over 52% of homes built before 1950.
Collingdale: Median year built approximately 1951.
Sharon Hill: Approximately 30% pre-1950, substantial 1950s–1960s component.
Folcroft: Median year built approximately 1955 — postwar peak asbestos era.
Ridley Park: Approximately 35% pre-1950, including Victorian homes from the 1870s–1910s among the oldest in the county.
The Materials That Correspond to Each Era
The construction year of a home predicts which asbestos-containing materials are most likely to be present:
1900–1940 construction (Chester, Darby, Collingdale, Lansdowne):
- Steam pipe insulation and boiler insulation — high probability, often original
- Early asbestos-containing plaster
- No floor tiles yet (these came with mid-century renovation)
1940–1960 construction or renovation (most of Delaware County):
- 9×9 vinyl-asbestos floor tiles in kitchens and bathrooms
- Black mastic adhesive
- Transite (asbestos-cement) siding and roofing products
- Acoustic ceiling tiles in finished spaces
1960–1980 construction (Folcroft, outer townships):
- 12×12 floor tiles (also commonly contain asbestos)
- “Popcorn” spray-applied acoustic ceiling texture
- Asbestos-containing joint compound on drywall
- Duct insulation and asbestos tape on forced-air systems
What This Means in Practice
If you own or are buying a home in Delaware County built before 1980, the data says you are more likely than not to have asbestos-containing materials somewhere in the structure. That is not a crisis — millions of Americans live safely in homes with intact, managed asbestos materials. But it is a condition that should be known and documented, not assumed away.
The most common reason homeowners in Delaware County are exposed to asbestos fibers is not because the materials were present — it is because they disturbed the materials during renovation without knowing what they were dealing with. Floor tile removal, pipe replacement, kitchen renovation, and basement finishing are the most common activities that generate accidental asbestos exposure.
The practical implication: Before any renovation that involves removing flooring, opening walls, disturbing pipe insulation, or demolishing any structure in a pre-1980 Delaware County home, a pre-renovation asbestos inspection is the correct first step.
ACI-TECH, INC. is based in Chester and serves all 49 municipalities in Delaware County. Contact us for a pre-renovation inspection or a baseline survey of your property. If testing confirms asbestos, we handle asbestos abatement and asbestos removal as well. For borough-specific detail, see our area guides: Chester, Upper Darby, Lansdowne, Darby, Collingdale, Sharon Hill, Folcroft, and Ridley Park. Free estimates available seven days a week — (610) 497-7162.
Sources
