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.

After a severe weather event, leaks in a commercial roof can become problematic very quickly. Besides disrupting business and making a mess, they can cause electrical problems, structural damage, and lead to roof failure if not promptly addressed.

When the roof of your commercial building, hotel, office, warehouse, or retail location is damaged or develops a leak, it should be treated as an emergency and handled immediately.

In this article, atlantacommercialroofingcontractors.com discusses weather-related roof damage, insurance company assessments, and how to hire a roofing contractor.

Causes of Commercial Roof Damage and Leaks

During or after a severe weather event, damages to your roofing system may become very obvious in the form of saturated walls, drips, or even streams of water cascading to the floor.

Hailstorms, hurricanes, and tornadoes in particular can beat up your roofing system, causing severe structural damages, such that extensive repairs or even roof replacement may be necessary.

However, sometimes a severe weather event isn’t necessary to expose an emergency situation. Over time, your roof must frequently endure extreme temperature fluctuations, and eventually, all it takes is a rain shower on a mid-summer afternoon to rapidly cool a nearly 200-degree roof and presto! You’ve got leaks and an emergency on your hands.

Roof Assessments and Insurance Inspections

If your roof damage emergency is the result of an act of God, before any major work begins, you must file the insurance claim. To do so, gather your policy number(s), facts about the situation, and call your insurance carrier to request an assessment.

During an evaluation inspection, the adjuster must determine the following when assessing the total of your loss:

• What is the extent of the damage?
• How much material is needed for repairs?
or
• Was the roof damaged sufficiently to declare it a total loss?
• How much material is required for replacement?

To ensure that you will receive the maximum benefit from your insurance policy, call a professional roofing contractor to have your own independent assessment done.

Request a Reinspection – If you find discrepancies between the insurance adjuster’s findings and those of the roofing contractor, you have the right to request a reinspection or contract an insurance public adjuster.

Reinspections are common practice, in which the insurance adjuster will meet with the roofing contractor to review the damages done to your roof.

Upon approval of the claim to repair or replace your roof, your insurance provider may select the roofing contractor to complete the work. They may also leave that determination up to you.

Note: In areas where a disaster has occurred, insurance companies may set up and follow special temporary procedures to expedite repairs and rebuilding. In these scenarios, it is important to keep receipts and records for temporary repairs, as the insurance company will likely reimburse you.

Hiring A Roofing Contractor – What to Look For

Natural disasters and severe weather events tend to attract some of the worst characters in the roofing business that prey on unsuspecting property owners who are under pressure to get things back to normal.

Replacing the roof of a building is a significant investment that needs to be done right, by a contractor that can be fully vetted and held accountable for the quality of their work. When fielding bids from contractors to repair or replace your roof, consider the following factors into the decision-making process.

Does the contractor have:

• A written proposal?
• A valid business license?
• Proof of insurance
• A permanent business location?
• In-depth knowledge and understanding of your roofing system?
• Up-to-date industry education?
• Financial stability?
• Material and installation warranties?
• A maintenance proposal?
• An effective safety training program?
• In-state references?

Also look for:

• Manufacturer certifications.
• Proof of continuous training.
• Roofing association memberships.
• Industry awards and recognition.
• Good and bad press or reviews.

Be wary of contractors which:

• Provide a seemingly unrealistic high or low bid.
• Only provides out-of-state references.
• Request money before any on-site material delivery.
• Only deal in cash.
• Cannot verify their company information and statements.

A fast way to address all of the above is to request a “Roofing Contractor Qualification Statement.” This document collects in-depth company information, references, history, and financial stability neatly organized to facilitate your evaluation of that company.

Managing Your Commercial Roof Seamlessly

The weather and harsh conditions a commercial roofing system must endure dramatically influences its lifespan and necessity for repairs. When the need arises, and it eventually may, you should be prepared to quickly file a claim and call in a professional roofing contractor.

With the above information, you can now identify an emergency roofing situation, effectively work with your insurance company, and thoroughly vet the contractors bidding for your job.

Without your prompt action, your commercial building will suffer significant losses or temporary closure when severe weather leaves your roofing system vulnerable, damaged, destroyed, and leaking.

Sources:
https://www.fema.gov/
http://www.nrca.net/
https://disastersafety.org/ibhs/hiring-a-professional-commercial-contractor/
http://www.everybodyneedsaroof.com/Roofing-Information-For-Building-Owners

See Commercial Roof Repair, Insurance Claims, and Hiring Contractors for the first version of this content.