Residential Roofing Terminology 101: 17 Terms You Should Know

Every building trade has its peculiar words and terms. A dog’s leg is a specialized carving chisel. House framers know how to cut birdsmouth notches in rafters. Residential roofing terminology can also be confusing to Florida homeowners. These 17 terms are helpful to understand and use when chatting with your neighborhood roofer.

1. Decking or Sheathing

Atop your home’s rafters are thin wood sheets, either plywood or oriented strand board (OSB), known as decking or sheathing. They form the foundation for your chosen roofing material

Roofers fasten these sheets to your rafters with long nails for strength; the decking must support all the roofing material.

Decking or sheathing is intentionally installed with tiny spaces between each sheet to allow thermal expansion. Don’t worry; water does not get in because of your roofing and underlayment. 

2. Drip Edge

Ah, science! Science tells us that water has surface tension and can move uphill by capillary action. The technology of roofing overcomes capillary action by forcing water to fall off the sides of your roof (where you do not have gutters).

Along the edges of your roof installers lay down long, thin strips of metal. Each strip has a wavy edge and is slightly raised from your roof and fascia boards. Water drips onto the drip edge, is ushered away from your roof and fascia, and falls to the ground. This prevents wood rot in the fascia and water infiltration from capillary action. 

3. Eaves and Fascia

Sloped roofs come to an end at your home’s eaves. The eaves are the small, horizontal space between exterior walls and roof end. The ends of the roofing rafters are covered with horizontal boards, fascia. The eaves are covered with soffit panels and soffit vents to allow air to circulate upwards into your attic. 

4. Felt or Underlayment

Between your decking or sheathing and your finished roofing material, roofers roll out felt or underlayment. This thin material is either stapled down or self-adheres. It forms a watertight barrier. When nails are driven into shingles and then the sheathing, they pass through the underlayment, which seals around and grips each nail like a tight-fitting collar. 

5. Flashing

Thin metal is used to bridge gaps between unlike materials, as when a roof is built around a stone chimney. You cover any gap with flashing, usually a thin aluminum or copper sheet.

From the safety of your yard, you can usually see step flashing rising up around your chimney to prevent water leaks around the masonry. Flashing can also be rubber material or even a brushed-on coating, so long as it permanently seals any gap. 

6. Penetrations

When any object moves through your roof from inside your home, that is a penetration. Penetrations are literal holes in your roof, for things like skylights, kitchen and bathroom vents, sanitary stacks for toilets, and electrical conduits.

Every penetration requires careful sealing, using either flashing, rubber boots, or caulking to prevent water infiltration. 

7. Ridge

The horizontal top of your roof is its ridge. The two faces of your sloped roof meet at the ridge, which is usually capped with ridge vents to allow for air circulation in your attic. Ridge vents look like furnace filter material, but are far stiffer and tougher; your decorative shingles sit on top of the ridge vents. 

8. Slope or Pitch

The angle of your roof — how much it tips upward from horizontal — is its slope or pitch. Residential roofs are usually steep-slope, meaning they angle up at least four inches for every 12 inches horizontally (4-in-12, or 4:12). Florida’s friendly weather means we seldom have to worry about snow load on our roofs the way our northern neighbors do, where 10-pitch roofs are common. 

9. Square

One hundred square feet of roofing, in any material, is a square. Shingles are packaged so three bundles equal one square. Roofing work of the last century saw roofers shouldering these 90-pound bundles up rickety ladders; modern techniques include rooftop delivery of entire squares for greater safety and efficiency. 

10. Soffits

Soffits are the horizontal underside of your home’s eaves. They are covered with soffit panels and soffit vents to allow air to circulate into your attic. Soffit panels and vents can be metal or vinyl. 

11. Valley

When two roof surfaces meet downhill, they form a valley. A valley is the opposite of a hip. It is always lined with flashing to prevent water infiltration. Sometimes (and especially if you opt for copper flashing) valley flashing is place atop the metal panels or shingles for a deliberate, decorative look. More often, the valley flashing hides underneath the rows of shingles or metal panels meeting at crisp edges at the valley itself. 

12. Vapor Retarder

A vapor retarder is a material designed as part of the roof to reduce the movement of water vapor into the roof system, where it can condense. Without vapor retarder, wet areas of your home — kitchen, laundry room, bathrooms — can send water vapor into your roof. Once water vapor is in your roof and attic, you can expect to see mold, mildew, and a decreased lifespan for the roof, no matter the material. 

13. Hip

The hip of a roof is the outside angle where two sloping roof surfaces meet. If a valley is a downward fold, a hip is an upward fold. A hip is often capped with ridge shingles, but your roofer may suggest ridge vent shingles for improved airflow. 

14. Vents

Roofing vents include soffit and ridge vents to allow air to rise up from the exterior walls, circulate in your attic, and exit by ridge vents. Vents can also include kitchen and bath vents to exhaust fumes and offensive odors. Motorized vents can be installed as roof penetrations to dispel heat from your attic. 

15. Edging strips

Edging strips are synonymous with drip edge and can also go by other names, such as D-metal or drip edge flashing. They are always used along the perimeter of your roof to improve drainage. 

16. Fire Rating

All roofing materials receive a Fire Rating, telling the homeowner how well the material resists catching fire. Class A is the highest rating and is typical of nearly all residential roofing materials, from shingles to tiles to metal panels. Unfortunately, as shingles age, their fire resistance decreases. Your roofer can offer peace of mind — through annual inspections — to let you know when your “Class A” shingle roof has become a fire risk. 

17. Granules

Shingles are covered in chunky, ceramic granules in the exact color you desire. These granules serve several purposes: 

Since we started talking about birds and dogs, here’s a bonus item: many roofers carry a cat’s paw in their tool belts. This tool helps get stubborn roofing nails and pluck them out of Florida roofs.

Please contact us today at Alan’s Roofing so your central Florida home’s roof can perform at its best. We provide complete roofing services from roof inspection to roof repair and total roof replacement. Tap our vast experience working with shingles, concrete tile, metal roofing, and low-slope (“flat”) roofing!