Roofing Terms

Common Roofing Terms


This is the replacement cost minus the depreciation over time. Hypothetically, if you tried to sell your roof today, it would be the dollar amount you could expect to receive in the market place.  Did you know?! Fun fact: solar shingle


RCV stands for Replacement Cost Value. This is essentially the sum of the entire cost of a project (minus your deductible) to replace your roof.


Supplements are any items required to complete your job correctly that the insurance might have accidentally missed or will pay for once incurred, which means they reimburse us once we provide proof that we completed your roof using that item.

A permit is a great example: permit requirements and costs vary widely with each city, so most insurance companies expect this to be a supplement item. We pay for project permits directly, which could be anywhere from $20 to $150.  We will submit the permit receipt to the insurance company, who then releases an additional check to cover the cost of the permit.

We work with your insurance company to work out what’s fair for each project. For example, it might cost us $300 to remove and replace the flashing around your chimney, an item that the insurance might agree to pay only $275 for.

Since there might be some back and forth with pricing requests, discussing supplements may take a few weeks to several weeks, depending on the project.


The amount that you need to pay before your insurance agrees to pay the rest of the claim. This is agreed upon in contract when you first choose your insurance policy.


Most types of property depreciate over time: cars, roofs, furniture, equipment, etc. [The market doesn’t value a used item as much as a brand new item: you wouldn’t pay more for a used treadmill that you found at a garage sale than you would buying from a sports store.] Bottom line: depreciation is defined as a reduction in the value of an item with the passage of time, due in particular to wear and tear.


Eaves function to keep rain water away from the walls of your home: they are the edges of the roof that overhang the face of a wall.

Ice Dam

CertainTeed defines ice dams as “when heat from the inside of a home escapes into the attic and warms the roof decking during the winter. This heat, combined with heat from the sun, can melt snow on the roof. Melting snow on the upper roof and in the valleys then runs down toward the eaves as water. When it reaches the cold eaves and gutters, it refreezes. The continual thaw and re-freeze process creates ice dams. The result is water backing up under the roof shingles or behind fascia boards where it can soak through the roof decking or wall sheathing, causing damage to attics, ceilings and walls.”


The surface that is fastened directly to your rafters – that your roofing material fastens to.


In some situations, can be felt paper or synthetic materials.

Felt is a resin paper dipped in oil. There’s common issues with felt drying out or ripping. We don’t use this, mainly due to the ineffectiveness and lack of durability.
Synthetic materials are used to provide a barrier against water damage and leakage and offer breath-ability.

Ice and water shield

Ice and Water Shield is a layer underneath your roof to protect your home from ice and water damage. It’s quickly become the gold standard for creating leak-free roofs in all climates.


Flashing is just material—usually aluminum or galvanized steel—that’s used over joints in roof and wall construction to prevent water seeping in and causing damage. Depending on the style of your house’s roof, you probably have it in the valleys, around the chimney and pipes, and around any dormer windows or skylights. Most damage shows up either in flashing that’s deteriorating due to weathering and oxidizing, or in flashing that has come loose.


This system both pulls in external air and exhausts internal attic air. This provides continuous airflow to eliminate damaging conditions like humidity and excessive heat. In the summer, ventilation minimizes heat buildup so air conditioners have to run less and heat doesn’t damage the roof structure or the shingles. In the winter, ventilation balances temperatures to reduce the water damage from ice dams.

*Tip: Poor attic ventilation will greatly reduce the service life of roofing shingles.