Without knowing the basic components when having your roof repaired or replaced, an unscrupulous roofer can take advantage and charge you more money than necessary. Knowing the various parts that compose a roofing system will help you understand the work being done, and ensure you are treated fairly.

atlantacommercialroofingcontractors.com gathered the following information to help you gain a deeper understanding of the complexity and needed parts of your home’s roofing system.

Parts of a Roof

The following are 18 parts of a shingle roofing system and their purpose:

1 – Ridge Board

This is the wooden or metal board that runs along the peak of the roof. Rafters and trusses connect to the ridge board, creating a cohesive framework for the roof.

2 – Collar Beam

A collar beam is a horizontal beam that connects two rafters that intersect at the ridge.

3 – Solid Decking

This decking is composed of solid materials, is strong and stable for bearing potentially heavy loads.

4 – Rafter

One of the multiple diagonal members of the truss that meet at the apex to support the roof deck and its load.

5 – Felt Underlayment

This layer of material is a waterproofing layer made of regular felt. It is stacked above the solid decking board and then covered by shingles or preferred roofing materials.

6 – Shingles

Shingles are the roof covering typically flat and cut or molded into rectangular shapes. Shingles can be made of multiple materials like slate, wood, stone, plastic, metal, and composite materials.

Suppliers can offer shingles in a wide variety of shapes, sizes, and colors.

7 – Chimney

The vertical structure penetrating through the roof that is responsible for safely ventilating smoke and combustion or residual gases from a fireplace, boiler, or stove (wood-burning or gas equipped) to the outside environment.

8 – Chimney Flashing

A waterproofing seal installed at the penetration point of the chimney through the roof and used to prevent moisture infiltration.

A small structure called a cricket may also be installed on the raised side of the chimney to prevent moisture and debris from gathering and damaging the roof or chimney.

9 – Vent Pipe Flashing

This installation is weaved or layered into the shingle pattern preventing damage from water seepage into the roofing system.

10 – Spaced Sheathing

Spaced sheathing, also called skipped decking, refers to the type of decking identified by boards running horizontal to the rafters with a 4”- 6” space between them.

11 – Valley Underlayment

This waterproofing layer protects roof valleys from ice and water damage.

12 – Valley Flashing

Valley flashing is a waterproofing seal installed along valley lines.

13 – Lookout

A lookout, lookout rafter, or roof outlooker is a joist that extends in cantilever out from the exterior wall (or wall plate) of a structure, supporting the roof sheathing and providing a nailing surface for fascia boards. When not exposed, it can serve to fasten the finish materials of the eaves.

14 – Fascia

The fascia is the often attractive board along the side of the overhang and the roof that helps your roof have a completed appearance. Your gutters will sit atop your facia board. The fascia is sometimes called a “transition trim” between the home and the roofline.

15 – Rake

A rake board covers the top edge of siding where it meets the roof or soffit if there is an overhang on the gable end. A rake prevents rain from running behind it.

16 – Gutter

Gutters are the horizontal metal (typically aluminum) part of the water drainage system that are usually installed along the eave edges of your roofing system, or along roof features like dormers. Gutters are open at the top to collect rainwater flowing off the roof, then directing it into the downspouts.

17 – Down Spout

The primary job of gutters and downspouts is to collect water from the roofing system during rainstorms (or from melting snow) and safely divert it away from the foundation of the structure.

18 – Splash Block

Splash blocks are rectangular pieces of plastic or concrete located beneath the end of downspouts. Splash blocks are used to direct water as far away from a structure as possible while preventing soil erosion, eventually causing foundation issues.

While there are many more components that compose a roofing system, knowing the 18 listed above will give you sufficient dialog to properly address and negotiate eventual roof repairs or replacement.

Understanding What Makes a Roof

In this article, you discovered 18 roofing components that are fundamental to the proper functioning of a sloped, shingle roofing system.

The ability to address your roofing system issues directly with your roofer in clear and concise vocabulary will help you get the work done that you need.

Not knowing how to communicate your roofing system issues clearly can result in expensive, unneeded repairs, compounding existing problems, or the risk of being taken advantage of and overspending.

Sources:
goconstruct.org/why-choose-construction/whats-happening-in-construction/what-are-the-different-parts-of-a-roof-and-what-do-they-do/
checkbook.org/v2/docs/roofers/all-areas-roofers-parts-of-a-roof.pdf
asphaltroofing.org/asphalt-roofing-systems-components/

See 18 Parts of a Roof and What They Do for the first version of this content.

Prevent your flat roof system from collapsing under the weight of standing rainwater. Without sufficient drainage, water can build up on your commercial roof and cause catastrophic losses when the roof succumbs.

atlantacommercialroofingcontractors.com gathered information on three roof water drainage systems and how they remove potentially thousands of pounds of water from your commercial flat roofing system.

Roof Drain Types

Whether you are installing a new roof or performing renovations on an old roof, the drainage system must be considered and able to usher water off of the roof with ease. The following are three principal flat roof drainage systems:

Inner Drains – These drains are commonly found on large building roofs near the center of the building. Inner drains provide the following benefits:

• Attached to a system of pipes that drain water through the roof, water is kept from the foundation and walls.
• Since the building and walls naturally protect inner drains, there is no concern for their freezing, cracking, or failing during the winter months.
• Inner drain strainers help keep debris from clogging the drain pipes and can be custom-made to fit your roof and regional climate.

Some essential issues to take into consideration are:

• A small amount of debris can render the strainers ineffective, clog the system, and cause water to pool on your roof.
• Verify the appropriate number of drains for the size of your roof. Too few drains and the system could easily be overloaded, causing water to back up and pool on your roof.
• Inner drains are more expensive to maintain. These drains require a specialized technician to service, clean, and maintain them.
• Of the three drain systems presented here, inner drains are the most expensive to install.

Rain Gutters – With the ability to serve all types of roofing systems, rain gutters together with downspouts are the most common type of water drainage system in use. Gutters offer the following benefits:

• The system is inexpensive
• Easy to install
• Effectively controls the flow of watershed from a roofing system
• Shields doorways, vents, and windows
• Keeps water from pooling near the building

Some essential issues to take into consideration are:

• Gutters require maintenance and cleaning year-round
• Gutters are prone to becoming brittle and cracking
• Gutter brackets may come loose or give way under excessive water or leaf weight
• In winter, ice dams can cause cracking
• Downspouts may clog causing water to back up and overflow in the gutter

Scuppers – This drainage system consists of along the outer walls (curbs) along the roofline. Water passes through a metal box that surrounds and protects the scupper. Consider the following benefits:

• Installation of the drainage system is extremely low cost
• If designed wide enough, there is virtually no clogging
• Water is propelled away from the building
• Custom scuppers can add to the building’s architectural appeal
• This draining system is almost maintenance-free

When the design and installation of scuppers are carried out correctly, the system provides the best value of the different drainage systems. Thus, scuppers are preferred for the efficient draining of water from your flat roof system.

The only issue with scuppers is when they are attached to downspouts or gutters, which may clog – scuppers function best when unattached from other systems.

Roof Load and Water Weight

Water removal from your roofing system is of supreme importance. As water pools and rises, it adds weight to your roof’s load and can cause a catastrophic roofing system failure.

A gallon of water weighs 8.34 pounds. During a rainstorm that drops a half-inch of rain, 300 gallons of water can accumulate on a 1,000 square foot roof. That is an additional 2,502 pounds added to your roof’s load.

To calculate rainfall accumulation or runoff, use the following equation:

1) Convert the footprint of your roof to inches. A 50’ by 50’ roof would be 600” by 600.”

2) Multiply the square footage of the roof (600” X 600” = 360,000”) by the number of inches of rainfall .5” for this example which equals 180,000

3) Divide the number by 231 to get the number of gallons (231 cubic inches = 1 gallon). In this case, 180,000 divided by 231 equals 779.22

4) 780 gallons of water weighs about 6,500 pounds, potentially added to your roof.

In this example, we see the potential for a roofing system partial or total failure due to an exceeded load capacity. To learn more about commercial roof loads, read atlantacommercialroofingcontractors.com/what-is-commercial-roof-load-why-you-need-to-know/

Commercial Roof Drainage Systems

In this article, you discovered information about three types of water drainage systems for commercial roofs and the impact that pooling water can have on your roof load.

By installing a drainage system that facilitates water runoff from your roof, you are extending the life of your roof and making the building a safer place to be.

If you fail to provide adequate drainage or regular maintenance to keep your systems working properly, the structural integrity of the roof, building, and its occupants are at risk.

Sources:
http://www.ashireporter.org/HomeInspection/Articles/Flat-Roof-Drainage/2554
citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.359.7775&rep=rep1&type=pdf
digitalcommons.calpoly.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1069&context=aen_fac
sciencenotes.org/much-gallon-water-weigh-easy-calculation/

See 3 Commercial Roof Water Drainage Systems for the first version of this content.