A commercial roof replacement is a major investment – one you want to enter into with eyes wide open. What is involved in installing a new roof? Will you be tearing off the existing roof, or simply installing the new one over the old? What type of roof do you want? All of these and more affect your bottom line.
Let’s delve right into some of these questions. First, what kinds of roofs are on the market today, and how long are they expected to last?
Your Choices in Commercial Roofing
Let’s look at your options for flat roofs. Most commercial buildings use these flat roofs because they cost less and are easier to maintain. In truth, though, no roof is completely flat — or at least it shouldn’t be. Most “flat” roofs are pitched between 2 and 10 degrees to prevent water from pooling and causing costly damage. Let’s take a look at a few of the common commercial roofing options.
This roofing system consists of alternating layers of roofing felt, waterproofing material, and hot tar (or bitumen).
- Pros: Fire resistant, inexpensive, and will last for 10 plus years.
- Cons: Installation is messy and materials give off a strong odor.
This type of roof consists of a single layer. This layer could consist of EPDM (ethylene propylene diene monomer), PVC (polyvinyl chloride), or TPO (thermoplastic polyolefin). For an easy way to keep these single-ply options straight, check out our Roofing Material Cheat Sheet, which outlines the differences.
- Pros: This roofing system is flexible, easy to install, and usually lasts between 20-30 years, depending on weather and surrounding conditions.
- Con: This type of roof is only one ply, which leaves you more vulnerable to punctures and damage.
Sprayed Polyurethane Foam
Also known by its acronym, SPF, this roofing system is a liquid sprayed over an existing roof, and then treated with a protective coat to help it last longer.
- Pros: It’s lightweight, flexible, and insulates well.
- Con: Although it can last 20 years or more, the protective coating needs to be reapplied every 10-15 years.
This is one of the oldest forms of roof, and consists of a flat layer of granulated rolled roofing.
- Pro: This system is cheap and quick to install.
- Con: It usually only lasts about 10 years, depending on the structural slope of roof.
Also known as standing-seam roofing, this type of roof consists of interlocking panels of steel, aluminum, copper, iron, and other metals.
- Pros: These roofs are known to be lightweight, durable, and to last 20 plus years, depending on the slope of the roof.
- Con: This roofing system is one of the most expensive roofing choices on the market.
Roof Installation Costs to Expect
- Roof Removal and Disposal – $1.00-$4.00 per square foot, depending on how many layers need to be removed.
- Built-Up Roof – $2.50-$5.00 per square foot
- Single-Ply Roof – $3.00-$4.00 per square foot
- Sprayed Polyurethane Foam – $1.50-$6.00 per square foot
- Asphalt Roll – $1.50-$2.50 per square foot
- Sheet Metal Roof – $5.00-$10.00 per square foot
Please note, these cost estimates are conditionally based on the thickness of roof, surrounding conditions, as well as other factors mentioned below.
Factors That Affect The Cost Of Your Roof
Size and Type
This one may seem obvious, but nonetheless it’s an important factor in determining cost. Although a larger square footage means more materials and labor, the overall price per square foot may go down as the size of the roof goes up.
How many objects protrude out of your roof? These mean more work, and more areas to cut around and seal. Does the slope of the roof leave it prone to pooling water? Costs may rise if the slope needs to be increased, or if a drainage system needs to be installed.
Certain factors of the location can raise the price. Perhaps your commercial structure is located in an area that requires more permits. Or maybe the weather at your location makes it harder to work — bad storms or cold conditions can raise the costs of a roof replacement. These factors can cause the cost of a replacement roof to fluctuate by upwards of 30%.