Most homeowners do not choose a roofing material so much as replace what was already there, and most of the time that is the right call, because the original choice was usually driven by the shape of the roof rather than by taste. Pitch decides more than preference does. A steep roof and a nearly flat one need fundamentally different systems, and putting the wrong one on either is how you end up replacing it twice. That said, when the pitch allows for more than one option, the differences are worth understanding, because they play out over decades rather than over the first invoice. Here is what each of the four systems actually does well, and the kind of house each one belongs on in New Jersey and Pennsylvania.
Asphalt Shingle: The Default for Good Reasons
Architectural asphalt shingles cover most pitched roofs in this region, and that is not laziness. They cost less up front than the alternatives, they come in enough colors and profiles to suit almost any house, and the installed base means any roofer can work on them and parts are never a problem. They handle the freeze and thaw cycle well on a decent pitch. The trade off is lifespan. You will replace a shingle roof at least twice in the time a metal roof lasts, but the lower up front cost and the simplicity keep them the default for good reason on most homes here.
Metal: Higher Up Front, Longer Everything
Standing seam and metal panel roofs cost noticeably more to install and then largely leave you alone. They last far longer than asphalt, they shed snow rather than holding it, which matters in the Poconos and the higher elevations, and they resist wind uplift better than almost anything. The higher up front cost is the barrier, and it is a real one. But measured across the full life of the roof, a properly installed metal roof often works out even or ahead, and it does it with far less maintenance and far fewer interruptions along the way.
Flat and Low Slope: A Different Problem Entirely
Flat roofs are not really flat, they are low slope, and they cannot use shingles at all. Shingles work by overlapping and shedding water downhill fast. On a low slope, water moves slowly and sits, and it will find any lap in a shingle system. So flat roofs use membrane systems that seal continuously instead of overlapping. You see these on additions, porches, dormers and commercial style structures, and plenty of houses have a low slope section somewhere even if the main roof is pitched. That section needs its own system, chosen for how water actually behaves on it.
EPDM Rubber: The Practical Flat Roof Answer
EPDM is a rubber membrane that has been the workhorse of low slope roofing for a long time, and its reputation is earned. It handles standing water, which is the whole point on a flat roof. It expands and contracts through temperature swings without cracking, which matters a great deal here where a single week can run through a forty degree range. It repairs cleanly, so a puncture or a failed seam is a patch rather than a full redo. It is not the only membrane option, but for most residential low slope work in this area it is the practical, proven answer.