Roofing Basic: Know the 10 Most Common Terminologies

Choosing a new roof can be a bit of a daunting experience, especially if you are not familiar with roofing terminologies and what they mean. To ensure that you are better informed and equipped, since an educated consumer is always a better consumer, here are 10 of the most common and useful roofing terms – along with easy-to-understand definitions.

Clay Tiles

Clay tiles are historically one of the best and most enduring roofing materials of all. They were used in early American settlements dating back to the 1500s, and in the Spanish settlement of St. Augustine in Florida. They are extremely tough, even when exposed to harsh sunlight and heat, strong winds, and heavy rains – yet they are rather lightweight so they put less strain on a roof when installed properly. Clay tiles are fired nearly 2,000 degrees which makes them fade-resistant, durable, and virtually impervious to fire. They typically have a life expectancy of about 50 years.

Concrete Tiles

Concrete is sometimes used to make roofing tiles that have the basic similar appearance of a traditional clay tile – like those seen on Mediterranean style or Spanish style roofs. Concrete tiles, which come in a variety of colors, are less expensive than genuine clay tiles, so they can be a more economical option. If installed and maintained correctly they can last a few decades.


The deck is the supporting structural component of the roof. A deck on a roof acts like the floor on top of which the other layers of the roof such as waterproofing membranes and shingles are applied. Once completed, the deck of the roof is completely hidden beneath the visible roof and above the attic of the building.

Drip Edge

A drip edge is a structure that runs beneath the roofing material and then extends beyond the edge of the roof. The purpose of a drip edge is to give water a surface to flow along until it is past the edge of the roof, where it can then flow into the gutters without risk of getting underneath the roof to do damage.

Elastomeric Coating

An elastomeric roof coating is a rubberized or acrylic roof coating membrane that provides a continuous barrier to protect a roof from water leakage. These coatings, used on flat roofs, can also reflect solar heat in hot climates to reduce air conditioning bills. When installed properly this kind of protective layer can withstand extreme weather conditions and last decades.


Flashing is material that is designed to create a weatherproof barrier or seal the roof system at places where there are joints or interruptions in the roof surface. When a vent pipe or chimney extends through the roofing surface, for example, flashing needs to be placed around it to seal that opening around the edges so that water cannot leak through it.

Impact Resistance

The ability of a roofing material to resist damage from falling objects or people walking around on it is measured in what is called “impact resistance. “ The more impact resistance a roof has, the less vulnerable it will be, for example, to getting pierced by a limb falling out of a tree.


The lap is the part of a roofing, waterproofing, or flashing component or material installation where it overlaps with another section of the another part of the roof that is adjacent to it.


A roof is actual a system of layers, one on top of the other, that form a protection barrier from elements such as wind and rain. In that way it is kind of like laying of clothes in wintertime, when you wear one or two layers under your outer garment to keep you warm and dry. But if you install a new roof over the top of the layering of an older existing roof, that can make it harder for the new roof to fit properly without waves, bumps, or other inconsistencies. Sometimes it is possible to repair a roof using additional new layers, but the best method is to remove the old layers completely and then start from scratch with a fresh new roof.

Metal Roofing

Metal roofs have been around for hundreds of years and are now making a huge comeback because they are lightweight – which puts less strain on your home’s structure – and they are relatively maintenance-free and fireproof. Modern metal roofing systems are highly energy efficient, can be ordered in a number of different colors, and will typically outlast a conventional shingled roof by many years. Because they are so durable and long-lasting some insurance companies even offer discounts for homeowner’s policies if the home has a metal roof.

Ridge Vent

The ridge is the peak of the roof that runs along the top edge, and a ridge vent is a device installed along that vertical ridge to allow the heat built-up in the attic to dissipate. Installing a ridge vent can be a good idea if you have problems with moisture trapped in the attic, for example, or in hot climates where the heat captured in the attic cannot escape – resulting in less efficient cooling of your home’s interior.


The underlayment, as the word indicates, is a layer that lies beneath the exterior layer of the roof. Usually it is made of asphalt-saturated felt or other sheets of material, and it is secured to the deck of the roof to create a barrier and help shed water while added an extra layer of protection to the roof system.