Mold Inspection & Testing in Sharon Hill, PA

Sharon Hill, Delaware County, PA

How does mold testing work in Sharon Hill?

Last updated June 21, 2026

Sharon Hill is a small, densely settled borough in eastern Delaware County, chartered in 1890 and built out almost entirely with the brick rowhomes, brick twins, and modest detached houses that went up across the inner-ring Darby-area boroughs from the early 1900s through the 1930s. It covers less than a square mile, bordered by Folcroft to the west, Collingdale and Darby to the north, Colwyn to the east, and Darby Township to the south, with U.S. Route 13 — Chester Pike — running the length of the borough as its commercial spine. The land here sits low, around 85 feet above sea level, and it drains toward Muckinipattis Creek, which winds through the borough and empties into Darby Creek a short distance downstream before Darby Creek reaches the Delaware River. That low elevation and the closeness of the Muckinipattis and Darby Creek corridors are the starting point for understanding why so many Sharon Hill basements hold moisture. Water moves toward the creek through the soil under these blocks, and after a sustained rain the seasonal water table rises enough to press against foundation walls that were never built to modern waterproofing standards. The foundations themselves are the second factor. Rowhomes and twins from this era were typically set on stone or hollow concrete-block walls, and block in particular wicks groundwater up through its cores and mortar joints, so a basement wall can stay damp for weeks without a drop of standing water ever appearing on the floor. Inside, the walls are plaster over wood lath, a system that absorbs and holds humidity through the seasons and can stay wet behind an intact surface long enough for mold to establish without any visible stain. Add in the original clay sewer laterals that run from these houses out under mature street trees and the public mains along Chester Pike and the side streets — laterals that crack, belly, and fill with root intrusion after a century — and you have a steady supply of below-grade moisture that feeds mold growth quietly. Bathrooms and kitchens in housing of this age were built with little or no mechanical exhaust, so shower and cooking moisture has nowhere to go but into the plaster and framing. None of this makes a Sharon Hill house a bad house. It makes it a house where moisture takes specific, predictable paths, and where testing tells you what is actually happening rather than what you can see.

In Sharon Hill, the pattern I see most often is a brick rowhome or twin with a stone or block basement that reads as bone-dry to the owner but shows elevated humidity the moment I put a meter on the lower walls. The borough's low position relative to Muckinipattis and Darby Creek means the soil around these foundations stays wetter, longer, than people expect, and block walls move that moisture into the basement air even when the floor never floods. A finished basement makes it harder to see — a lot of these houses had the lower level paneled or drywalled decades ago, directly over block, which seals whatever the wall was already doing behind a clean surface. When I test a Sharon Hill home I collect calibrated air samples from every area of concern — the basement, any finished lower level, and living spaces where someone has noticed an odor or a symptom — and I take an outdoor control sample the same day so the lab is comparing your indoor air against the actual spore load outside your door, not a generic baseline. Every sample goes to a PRO-LAB certified laboratory and results come back in 2-3 business days. I read the report and explain it to you in plain language, not as a table of counts you have to decode. I do not do remediation, so nothing I find is shaded by an interest in selling you a cleanup. I serve Sharon Hill alongside the neighboring boroughs, including Darby directly to the north. Call 610-348-6728 to schedule.

Why are Sharon Hill's 1900s–1930s homes at risk for mold?

Pre-1920 homes are among the highest-risk properties for mold growth due to stone foundations that wick moisture, lime mortar joints that crack over time, and original drainage systems that predate modern waterproofing.

How does Bob test for mold in Sharon Hill?

Bob follows a systematic approach calibrated to the specific risks of late 19th and early 20th century construction in Delaware County. All sampling protocols follow EPA mold testing guidelines:

What are common issues in Sharon Hill homes?

Based on 20+ years testing late 19th and early 20th century homes in Delaware County, these are the issues Bob finds most often:

• Knob-and-tube wiring still energized behind walls and under blown insulation
• Stone foundation moisture intrusion and mortar joint deterioration
• Lead paint on original trim, windows, and exterior surfaces
• Gas pipe conversions from original coal or oil systems with improper venting
• Original clay sewer laterals with root intrusion and bellied sections
• Aging slate or clay tile roofs with deteriorating flashing