Roof Anatomy 101
It’s important to understand the language used when referring to a roof structure’s components. It makes it easier to discuss the roof project with a contractor as well as understand what the terms in a roofing contract mean.
The decking is the foundation of the roof. The material does vary. The two most popular choices are oriented strand board (OSB) or plywood. The roofers attach the decking to the rafters with nails.
Underlayment is then layered onto the decking. Typically, it is a felt material made from durable paper dipped in asphalt. The underlayment provides an extra layer of protection if shingles should tear or break off. It is rolled onto the roof from the bottom edge of the roof. Each subsequent layer is overlapped on the previous layer. This guides any water to pour downward without leaking into seams.
The drip edges, or eaves flashing, are aluminum strips nailed over the underlayment on the edges of the roof and under the eaves. The drip edge stops water build up by sending it into the gutters.
Shingles are the outer layer of the roofing system. They can be made of asphalt, metal, clay, wood or other materials. In some localities, wood shingles are not permitted, so it is best to check building codes or a roofing contractor before choosing shingle material.
Roof flashing is a piece of sheet metal made from aluminum or steel. The flashing is placed over joints in the roof to prevent water leakage. Flashing is commonly seen around the area where a chimney meets the roof. Faulty roof flashing is one of the leading causes of roof leaks.
A soffit is a board that covers the gap from a home’s siding to the roof line. It’s located under the horizontal fascia board. Soffits help provide ventilation in attics.
The fascia are boards attached to the edges of the roof. The boards run horizontally and support gutters and drainage pipes. Decorative boards beautify the appearance of the house. Keeping gutters clean preserves the integrity of the fascia and soffits.
Oriented strand board (OSB)
Oriented strand board (OSB) is a manufactured wood particle board. It is made by combining adhesives and wood strands and compressing them into boards. Specific orientations are configured in the compression patterns. OSB can be identified by its distinctive look of visible wood strands.
Check the local building codes in the area where the home is located to see if there are any additional requirements. Though the components outlined are standard components seen in most every roof, localities may have additional requirements regarding materials and methods of installation. Areas known to have heavy snow conditions, hurricanes, tornadoes or earthquakes may have additional building codes for the roof to be in compliance. –Price Rite Roofing