How Long Does it Take to Install a Commercial Roof?

Roofer Installing a Commercial Roof
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Commercial roof installation is an immense job for Chicago-area businesses and roofers alike. Not only is roof installation expensive, but in some cases, it can affect your business if the building needs to be closed for repairs. It’s understandable then that many Joliet-area business owners want to know how long it takes to replace a roof.

Unfortunately, it’s difficult to predict exactly how long it takes to replace a roof due to several factors including materials, the roof type, permits, and even the weather. While it’s generally predicted that commercial roof installation can take anywhere from 2 – 4 weeks, only a professional roofer that has inspected your property can give you a proper estimate.

Learn more about commercial roof installation and the different factors that will affect your timeline with NIR below, or contact our team if you need to schedule a free inspection.

Type of Roof

The type of roof your business has will greatly affect your commercial roof installation time. In general, Crystal Lake businesses have one of three roofing types: flat, low slope, or pitched. We’ll go over the differences between them below:

Flat Roofs

  • The most common type of commercial roofing is found in Chicagoland and across the country.
  • They’re often cheaper to install than other roofing types since they require fewer materials, however, preventative maintenance is key since they’re prone to water spots and leaks.
  • These roofs are often the easiest to install and have a variety of materials that they can be repaired with. They can also have heating/cooling systems, satellite dishes, and other objects installed on top.

Low Sloped Roofs

  • Low sloped roofs can be found on commercial businesses, apartment buildings, or residential homes.
  • Low sloped roofs are also easy to install and a cost-effective way to save on building materials. They’re also designed for easy water run-off and drainage.
  • These roofs also have a large variety of materials that can be used, and maintenance is easier due to its design.

Pitched Roofs

  • Pitched roofs are most commonly used on residential homes, but they can still be found on some commercial buildings or alongside flat and low-sloped roofs.
  • Pitched roofs require more materials for repair/installation due to their larger design. However, their ability to easily drain snow and water means there’s less of a concern about water damage or mold.
  • Pitched roofs are much more complicated to work on, however, due to the extra safety precautions needed and the difficult maneuvering of sloped areas.

Roofing Materials & Availability

The type of roofing material you choose will also affect your commercial roof installation time. Tar and gravel roofs are often the easiest to install since they require only a few materials and steps, while others like Metal Roofing or Modified Bitumen Roofing require more materials, structural design elements, and installation tools. Look below to see the six most common types of roofing materials:

  • Built-Up Roofing (BUR) Membrane
  • Green Roofing
  • Metal Roofing
  • Modified Bitumen Roofing
  • Thermoplastic (PVC & TPO) Roof Membrane
  • Thermoset (EPDM) Roof Membrane

Another factor to consider in commercial roof installation time is the availability of each material. More common roofing materials will be easier to come by, but others may take longer to be created or shipped, which may impact how long it takes to replace a roof.

Permits & Third-Party Inspections

Roofing companies like NIR and commercial roofers near you are required by law to get proper permits and are subject to third-party inspections to ensure that the roof is being installed properly and following national, state, and local regulations.

Permits are a necessary part of commercial roof installation, but sometimes permits will need revisions if issues come up during repairs or installations. Commercials roofs are also subject to code enforcement and municipal regulations, which may require that different roofing materials or methods must be changed. Any changes made to the installation or repair plan, along with materials or methods will require a new permit, which may cause delays in your timeline.

Similarly, inspections are often carried out to ensure that codes and regulations are being followed, but inspectors are often on their schedule. Delays can occur if the inspector needs to reschedule or if the required paperwork isn’t immediately available when the inspector is on-site. When you choose a professional roofing company like NIR, however, you can have peace of mind that we’ll have the proper paperwork and provide quality workmanship that will pass an inspection.


The weather is the ultimate factor in your commercial roof repair and installation timeframe. Often, commercial roofers near you will give you a timeline and use the phrase “weather permitting”, meaning that if the weather cooperates, then your roof will be repaired within that timeframe. However, storms, rain, and snowy conditions will slow down and sometimes halt roof repair and installation completely. For this reason, it’s recommended that you perform any roofing repairs or installation in drier months when the weather is more cooperative.

Find Commercial Roofers Near You at NIR!

Many steps go into commercial roof installation, make the job easier when you use the NIR roofing company! You can set up a time to get a quote on your roofing repair or installation, then sign up for one of our roof care plans to get the most out of your investment.

Connect with NIR Today!

Get in touch with us now to discuss your roofing needs. Our flat roofing specialists are ready to answer any questions and recommend a course of care to protect your roof from any problems. We look forward to hearing from you!