You’ve figured out the cost of a new commercial roof (and if you haven’t, contact us to learn more). Now, you’re trying to figure out how long it will take to replace your commercial roof. How long will your roofing company be working and will this cause prolonged business disruption? When it comes to commercial roofing, there are a lot of factors that go into estimating how many days it will take to replace the roof.

The main factors in this equation include the type of roofing material being installed , the size of the roof, the complexity of the roof, and the number of roofers working on the project. But first, here’s how commercial roofing differs from residential roofing.


What is considered commercial roofing?

Commercial roofing is roofing designed for commercial facilities and larger properties, including business buildings, municipal facilities, schools, healthcare facilities, retail shops, and other large scale buildings. Unlike residential roofing, commercial roofing should always be performed by a licensed professional since it can involve the use of specialty tools and materials that, when installed properly, will allow the roof to last for decades. This can entail the installation of various roofing materials, such as built-up, modified (SBS), or single-ply roofing over tapered insulation systems for low-slope roofs, as well as asphalt shingles or metal roof panel systems over steep slopes, which can withstand adverse weather conditions. For this reason, a commercial roofing project can take longer to complete than a residential roofing project.


Commercial Roof Replacement vs. Commercial Roof Repair

If you’re experiencing roof problems, the first action you will need to take is to assess the amount of damage in your roof – do you need a simple roof repair or a complete roof replacement? Commercial roof repair is a quick solution for minor roof damage. Common issues such as broken shingles, damaged metal flashings, or small holes in the roof membrane can be repaired quickly without the need for a roof replacement.

However, if there is extensive damage to your roof, for example from a roof leak, water damage, mold growth, or even the natural wear and tear that comes with age, then it is time to replace the entire roof, which will require tearing out the old roof and stripping it all the way down to the deck, then installing the new roof.


How long does it take to tear off and replace a roof?

This can vary according to the condition of the existing commercial roof. For example, a commercial building less than 10,000 sq ft without any damage to the underlying building structure can generally be replaced with a single-ply roof in less than two weeks. However, in the case of a larger municipal building re-roof, with multiple roof decks and additional penetrations and roof-top units, the project can take up to three weeks because there is more labor involved and more surface area.


What determines how long your roof replacement will take?

Commercial roof replacement and installation can take anywhere from a few weeks to a month depending on several factors, such as the type of new roofing material desired to be installed, existing roof penetrations and conditions, size and surface area of the roof, lead time of material, and the number of roofing technicians working on the project. Here are some of the factors that can impact how long a roof replacement would take.

Type of Roofing Material

There are several types of roofing material for commercial buildings, which can influence the amount of time it takes for a roofer to install a new roof system.


Single Ply Roofing

Single ply membrane material prevents leaks and uses only a single layer of roof membrane, which will take less time. This system is low maintenance and energy efficient with a long-term lifespan, and eliminates the need for extra labor costs due to the difficulty involved in installing multiple layers of roofing materials. Single ply roofing is a cost effective and time-saving solution, making for a faster install and replacement process.


Built Up Roofing

Built up roofing systems are made up of several layers of roof membranes. The top layer is often made of fibrous glass fabric, which can be surfaced with mineral granules or energy-efficient coating. This roof is one of the most time-tested and durable waterproofing solutions available for business, but since it requires multiple layers, it can involve more labor and time for installation.


Metal Roofing

Metal roofs are arguably the most durable roofing system on the market which will last for many years with a minimal impact on the environment. They are a great solution for steep-slope building owners who want a long-lasting roof. Metal has great insulating properties which can reduce damaging heat buildup in the summer and retain warmth in the winter. When it comes to replacement and installation, metal roofing takes slightly more time to install than roofs such as asphalt shingles. However, the durability of metal roof panels will more than make up for the marginal increase in installation time.


TPO Roofing

TPO roofing is a type of Single Ply Roofing that features characteristics like high resistance to UV radiation, durability against chemical agents, and fire, mold and mildew resistant. TPO is a single-ply roofing system made of two sheets of polyester-based film individually coated with reinforced phenolic resins, which are bonded together to form a strong and lightweight sheet that resists damage. TPO is lightweight and requires less labor, making this a quick to install option for commercial roofing.


Shingle Roofing

Shingle roofing, including asphalt shingles and slate shingles, are one of the most common types of commercial roofing. Durable and effective, they provide excellent protection from the weather. The shingles are attached to the underlayment with fasteners.

Depending on the material, shingle roofing can take some time. Asphalt shingles will generally take less time to tear out and replace and can be done quickly. However, wood shingles, concrete shingles, and slate shingles will take much more time to install and replace.


EPDM Roofing

EPDM stands for Ethylene Propylene Diene Monomer. It is a synthetic rubber used to roof residential and commercial properties and has been effectively used in the roofing industry for over 50 years. Compared to other roofing material such as wood shingles, EPDM roofing will be faster to replace.


Tile Roofing

Durable and long-lasting, tile roofs last up to 50 years, require little roof maintenance, and install quickly. Properly installed tile roofs can save thousands of dollars on energy bills compared to other types of roofs. Tile roofs can take longer to install than other types of roofing.


Size of Roof

Size of roof is the most significant factor in determining how long it will take to install a new roof. Larger roofs are always more time consuming to complete than smaller roofs. Commercial roofing has different requirements than residential homes when it comes to the size of roof. Size is important, not only in terms of square footage, but the shape and angles of the roof itself.

The larger the roof, the longer it may take for a commercial roof replacement.


Type of Roof


Low Slope Roofing

Flat roofs are most commonly used on commercial buildings, warehouses, and large retail outlets where there is a requirement for an expanse of roof. Flat roofing systems can be covered with single-ply membranes, built up systems or reinforced coating applications . Since gravity is not helping to shed the water on a flat roof, as opposed to a steep slope roof, flat roofing is more complex to install, so it typically takes longer for a full roof replacement.


Steep Slope Roofing

Steep slope roofing refers to roofs that have a vertical plane with an incline of greater than 3:12. having the right professional roofing contractor for steep slope roofing is critical. Because the slope of the roof helps shed water off of the structure, steep slope roofs generally require less layers to be applied, making it quicker for installation and replacement.


How long can you expect your commercial roof system to last?

A commercial roof system is a major investment, and can have a tremendous impact on your facility’s energy efficiency and performance. Whether it’s an office building, manufacturing facility, warehouse, or retail store, it’s important to know that your commercial roof system has been properly installed so it can perform at an optimal level for 20-30 years.

The average commercial roofing system can last anywhere from 10-60+ years, but this is also dependent on the type of roofing material, quality installation, and level of roof maintenance. Roofing materials such as built up roofing can have a commercial roof lifespan of around 25 years, while a metal roof’s lifespan can be over 40 years when installed and maintained correctly.

Commercial roofing projects can last anywhere from a week to a few weeks, depending on the size of the roof and number of repairs that need to be made. Learn more about the different commercial roofing services we offer, such as built up roofing, metal roofing, asphalt shingle roofing, as well as steep slope roofing and low slope roofing. If your roof needs repair or replacement, hire a commercial roofing company with experience and expertise, such as Andy’s Roofing. Get a roof estimate and learn about our guarantee. Contact us today through our online form or by calling us at 510-777-1100.