The core trade, stated plainly
Vinyl is a plastic. It is colored throughout, so it cannot chalk the way a coating does and it never needs painting. Its weakness is impact in cold weather, when it becomes brittle enough to crack from a thrown ball or a hard hailstone. Older thin vinyl also sagged and warped near heat sources; modern insulated vinyl is a materially better product than what gave vinyl its bad name.
How each performs in this specific climate
The DMV gives siding a genuinely hard time: humid summers into the nineties, winters that cycle across freezing repeatedly, convective storms with hail, and remnants of tropical systems bringing sustained wind. Both materials handle the humidity fine. The freeze-thaw cycling is where vinyl's cold-weather brittleness matters and aluminum's does not. The hail is where aluminum's denting matters and vinyl's does not — vinyl usually shrugs off small hail that would dimple aluminum, but takes clean cracks from large hail that aluminum would merely dent.
Which one belongs on which house
Insulated vinyl is the right default for most full re-sides in the DMV. It adds real R-value to walls of this vintage that typically have none, it ends the painting cycle for good, and it is the lowest material cost of the realistic options.
Aluminum still wins in three places: trim capping and window wrap, where its formability is the entire point; soffit and fascia, where a vented aluminum system remains standard; and any home where you are matching an existing aluminum envelope you intend to keep.
Fiber cement is the third answer and often the correct one on the older architecture common in Chevy Chase, Takoma Park, Del Ray and Arlington. It costs more and installs heavier, but it holds paint, resists impact, does not dent, and reads correctly on a house that predates both of the other two options.
What we do about it
We install all three and we price them side by side on the same inspection, with what each one solves and what it does not. If a contractor only quotes you one material, ask why. Usually the answer is that it is the one they buy in volume.
Get it looked at, free
We inspect across Maryland — Montgomery, Prince George's, Howard, Anne Arundel, Frederick, Carroll and Baltimore counties. Free inspection, photo report within 24 hours, and the report is yours to keep whether or not you hire us.