A roof is a system, not just a layer of shingles. Beneath the surface there is underlayment, plywood or OSB decking, metal flashing where the roof meets walls and chimneys, rubber boots around vent pipes and the vents that let the attic breathe, and most leaks begin at one of those details rather than in the open field of the roof. Good roof repair in Lyndhurst starts by tracing the water back to where it gets in, since water runs along rafters and decking before it shows up inside.
Most Lyndhurst 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. Time does its own damage, with cracked and curling shingles and brittle sealants, and a poorly flashed wall, valley or skylight can leak on a roof that is only a few years old.
It helps to know a little about the roof before you talk to a roofing contractor. Write down where the stain or drip is, when it shows up and how old the roof might be. 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. The roofer works out the cause; you only need to describe what you see.