Commercial roof installation: how long does it take?


The two questions that a commercial builder asks himself when considering a roof replacement or a roof installation are:

  1. How much would a commercial roof installation cost?
  2. How long does it take to install a commercial roof?

Commercial roof installation is not a one-man job. Instead, a team of rooftop installers has to work concurrently to speed up the process. If done correctly, a commercial roof can last up to 40 years with regular inspection and maintenance. Otherwise, wait within a decade. This means that installing a commercial roof takes a long commitment and the decision to buy a new roof cannot be rushed.

Commercial roof installation factors

A commercial roof replacement can take three weeks to even two months. While the size of the roof plays a role in determining the amount of time it takes, there are other factors too. Let’s take a look at all of the factors:

Size of the property

As mentioned earlier, the size of a roof affects the timeline of the roof installation. Special strips of asphalt must be laid, which must be heated during use. As the roof size increases, preparations and planning are made to determine the best layout for the strips to be laid. In addition, large roofs mean additional solar radiation, and a special protective layer must be sprayed on the installed roof, which can only be done in several steps, as the setting of the layers takes some time.

Roofing material types

There are three main types of roofing materials used:

  • Built roof
  • Thermoplastic polyolefin (TPO)
  • Ethylene Propylene Diene Monomer (EPDM)

Built roof

With this type of roofing, a base film is attached to the existing roof. Tar, concrete, glue or heated tar is applied to the base layer, which acts as a sealant and adhesive. A layer of gravel is placed over this adhesive layer, providing weather resistance such as rainwater or hail. Finally, another layer of tar or heated asphalt is poured over for the final seal. This type of flat roof combined with a good gutter system is incredibly effective in areas with heavy rain or snowfall.

Thermoplastic polyolefin (TPO)

This type of roofing material was originally developed for pond liners and adopted for commercial roofs in 1989. In this type of roof, a polymerized membrane made of polypropylene and ethylene-propylene rubber is laid and secured with adhesives or fasteners. The white rubber top layer reflects most of the radiation and becomes thermally insulating. This is an inexpensive and effective roof solution for flat or slightly sloping roofs. The only challenge with TPO roofs is sealing the seams. While roofers use heat to seal the seams, it’s really important to maintain the thickness of the membrane, otherwise it can be easily punctured.

Ethylene Propylene Diene Monomer (EPDM)

Similar to the TPO roof, ethylene-propylene-diene monomer (EPDM) is a membrane made of monomer chains of ethylene and propylene that is connected to a diene comonomer that supports crosslinking through vulcanization. These are available in three different thicknesses: 0.045, 0.060 and 0.090 inches. The thinner foils are ideal for installation without crimping and chalk. However, you have to put an additional insulating sheet under the membrane. It is thermally tolerant in an extreme temperature range of -49ÖF and 300ÖF with no evidence of cracks or deformation. The installation method is similar to the TPO roofing membrane, that is, using adhesives or fasteners.

Installation of TPO and EPDM roofs only takes a day, but depends on material availability. While roofs built up can take more time, the materials would be readily available. On the other hand, the durability of built-up roofs replaces the other two types, so that you can choose between installation time and longevity.

Equipment on the roof

Most commercial rooftops are home to the outdoor units for HVAC, antennas or satellite dishes for telecommunications. When roof installation is considered, all of these devices become obstacles and must therefore be removed. Depending on the size and weight of the individual units, you will either need to hire specialized craftsmen or have roofers dismantle them manually. This manual disassembly (and reinstallation) adds up to the total time the roof needs to be replaced. The chimneys or ventilation slots must also be taken into account when installing the roof.

The weather conditions

For an efficient installation it is important that the roof surfaces are dry. Most roofers do not take on roofing projects on the days of maximum rainfall. Depending on when you decide commercial roof installation and where your building is, roofers give you a window of time based on the weather forecast.

The manning level

The more the better. If more people are working on the rooftop installations, they can do more work than a smaller team in a given amount of time. However, the increased crew members can also affect installation costs. When discussing your roof replacement project, ask your contractor about the strength of their crew.

Roof installation inspection

Another large part of the installation time is spent on the post-installation inspection. To avoid later deformation or leaks, roofers need to have their roof checked before handing it over to their customers. All the documents required to approve the installation can take some time and indirectly contribute to the installation time. Additionally, you will need to book appointments for inspectors who may arrive if no one is on site, so you will have to postpone the inspection.

Common reasons for delays in roof replacement

  1. Demolition before installation: manual work is carried out to remove the existing roof or at least to chisel out the affected areas. Post-removal cleaning is an additional delay in roof installations.
  2. Temporal sealing: When the older roof is removed, the machinery or structures below must be protected from the elements. This means that temporary tarpaulin or other waterproofing solutions must be installed prior to installing a new roof. Adding or removing the temporary waterproofing can take a few hours each day.
  3. Hazard Prevention: Since the roof installation is a construction project, it is important to take adequate precautions against the various types of hazards such as trip hazards, electricity and fire hazards. Additional time is spent eliminating the various hazards in the roof project.

Wrap up

When in the market for skilled Commercial roofing companyIt is important to take into account that roof installation takes time. It is important to consider all the factors that affect the deadlines of an umbrella project. We assume that the items listed above cover most of the aspects that extend the commercial roof installation project and will help you set a realistic deadline, as agreed with your roofer.