A roof is a system, not just a layer of shingles. Under them sit underlayment, decking, flashing at every wall, chimney and valley, boots around the pipes and vents along the ridge, and a leak usually starts where one of those pieces fails. Good roof repair in Newton starts by tracing the water back to where it gets in, since water runs along rafters and decking before it shows up inside.
Most Newton roofers sort roof problems into three groups: storm damage, wear and age, and installation details that were never right. Storms lift and crease shingles, bruise them with hail and drop limbs on the roof. Age shows up as curling, cracking, bald shingles and dried out pipe boots, while bad details show up as leaks at flashing, valleys and skylights no matter how new the roof is.
Before you call, a few details make the conversation with a roofer in Newton, NJ more useful. Note where you see water or stains inside, whether it shows up in every rain or only in wind driven storms, and roughly how old the roof is. Say what kind of roof it is, whether asphalt shingle, metal, tile, slate, cedar or a flat roof, since the repair depends on the material. You do not need to know the cause, only what you are seeing.