Basic Roofing Components You Should Know About

A roof is a system consisting of different components working together to accomplish one goal: to weatherproof your home. If you forgo the installation of a single part, the collective and long-term performance of the whole would suffer.

Basic Roofing Components

For State Roofing, these are the most important components you should know about before you tackle residential roof installation:


Also called decking, it serves as the base of your roof. Usually made with sheets of plywood, the sheathing is fastened to the rafters to create a solid foundation for the rest of the components. Its strength determines the structural integrity of the entire roofing system. Its design must be based on the local climate and the weight of the roofing materials you want to use.


This layer envelops the bare, underlying sheathing to keep it dry from wind-driven rain. The most common type of underlayment is felt, which is durable paper rolled on the plywood with multiple overlaps.


These thin pieces of metal are used to seal protrusions, perforations or gaps in the decking where water could seep through. Even if your existing flashings were still in fairly good condition, though, any roofing installation expert would discourage reusing them during roof replacement. Otherwise, they would age faster than other materials and pave the way for leaks.

Primary Coverings (Shingles, Shakes, Tiles or Interlocking Panels)

These are the materials comprising the top layer of your roof. They come in a variety of profiles and hues to meet unique aesthetic needs, but their shape and color also play roles in your roofing system’s performance.

Gutters and Downspouts

Whether you have a rubberized shingle or metal roofing system, your roof needs proper drainage to shed water efficiently and safely to the ground. A well-thought-out gutter system is key to keeping the chance of roof leakage, as well as untimely foundation damage and premature siding rot, to a minimum.

Entrust your project to a highly credentialed company to equip your home with the most suitable roofing system. Call State Roofing at (800) 810-7305 today to discuss your roof replacement project in Seattle, WA, or any nearby areas, and get a free estimate.

Skip to content