Residential Roof Anatomy

We always recommend clients get at least three estimates or bids from local licensed roofing contractors before choosing the best roofer for them. This is because you need to compare the line items and get a feel for the roofers, before trusting them to do the job.  

When reviewing those estimates, you’ll see all kinds of roofing terms. So, the more you know about the various components and roof anatomy used to build a residential roof, the more you’ll understand what the contractors are talking about. The same is true when it’s time to perform annual roof maintenance – you’ll have a better idea of what parts are the most important to inspect and maintain. 

15 Common Parts Of Roof Anatomy 

Here are 15 of the parts of roof anatomy you’re most likely to see or hear about when scheduling annual roof maintenance or hiring a contractor to repair or replace your roof:

Roof deck

The roof deck is to your roof what the foundation is to your house. It is usually made from plywood or structural wood and the rest of the roof is built from there. Any issues in the roof underlayment can cause critical roofing damage because it is hidden by the rest of the roofing elements. This is one of the reasons it’s never a good idea to “roof over” or lay new shingles over the old ones. It may seem like old or missing shingles are the problem when, in fact, there is an issue with the roof deck. Your roof deck should always be considered when a major roof repair or replacement is in question. 

Roofing underlayment

The underlayment is installed on top of the roof deck as an added layer of protection. Roof underlayments were historically made from felt, but today’s roofs are built using synthetic underlayment materials to repel moisture and minimize water infiltration from the surface to the roof deck, which eventually leads to roof leaks. Synthetic products also have a longer lifespan, which supports the integrity of your roof and may also reduce homeowners’ insurance premiums. 

Eave

The roof eave is the section of roofing that extends out, or overhangs, from where the roof meets the exterior structural walls. The longer the eave, the more protected you are from rain when walking around the perimeter of your home, and it also keeps water from seeping into exterior walls. 

Undereavevent 

There should be a strong partnership between your roof and your attic. The combination of a well-designed and constructed roof and an adequately insulated and ventilated attic go a long way in promoting whole-home comfort and energy efficiency. Under eave vents are placed in the eaves to help draw cool dry air into the attic. 

Ridge

The roof ridge (not part of a flat roof) is the elevated horizontal line or “top” of the roof, where the two planes of the roof meet. The ridge is the highest point of the roof and may also be called the peak. Hip and ridge shingles are designed specifically to wrap around the roof ridge to support water runoff. 

Ridge vent

Like eave vents, ridge vents are exhaust vents that run along the ridge. Warm, humid attic air rises up and releases from the ridge vent.  

Valley

In an A-frame, there are only two roof planes, and these meet to form the “A.” However, most contemporary homes are designed with multiple planes. The roof valley describes the V-shaped juncture where two sloping roof planes meet. These valleys are part of the roof drainage system. 

Hip

This is the opposite of the valley; it’s the ridge formed by the meeting point of two roof planes that meet to form a sloped edge that runs from the ridge to the eave. As with the ridge, we apply special shingles that wrap over the hip for water runoff. 

Dormer

These are raised areas of the roof, most commonly used to cover windows that project through the roof. 

Gable

Gable roofs have roof planes that meet at the ridge edges, without any hips. Roofs are typically divided into three design categories: hip, gable, and flat. Gable roofs are the most common, although modern architectural styles often prioritize flat roofs. 

Flashing

Metal flashing forms a water barrier at joint openings, around chimneys, and any dormer windows or skylights. 

Drip edge

A type of flashing installed at the roof edges to help control the flow of water away from the fascia and to protect the underlying roofing components 

Water (and ice) barriers

Depending on the climate, ice and water barriers are an additional layer adhered to the eaves, side-walls, valleys, and other areas to protect from wind-driven water infiltration or ice dams. 

Shingles, tiles, metal, etc.

These materials are the final layer of the roof, installed to protect the roof structure and encourage water drainage. They are available in multiple styles, colors, and price points.  

Gutters and downspouts

These are active players in the roof drainage system, carrying water runoff away from the roof and walls (fascia), as well as the foundation.  

Now that you’ve learned more about the roof anatomy of a residential home, schedule an inspection with Central Bay Roofing. We provide clear, itemized estimates of all parts, services, and labor. 510) 521-7334.