Modified Bitumen Roof Life Expectancy

built up roof

Choosing modified bitumen

We know the summers can be short here in Maryland. Did your commercial building modified bitumen roof show any signs of leaks during the short spring? If so, you need to address that now before the winter rolls in again. 

You want to start by finding a roofing contractor that is experienced in how to repair modified bitumen roof. As you interview 2 to 3 different contractors for quotes, ask for their warranty in writing and a list of recent commercial roofing customer that have a modified bitumen roof installed and/or repaired by them.  Then follow up with those names by calling and inquiring on the job that was performed. 

If it is determined that you need a new modified bitumen roof, the roofing contractor you choose should know how to remove modified bitumen roofing as well.  It isn’t as easy as just scraping it off. There is a process to be followed so that the underlying roof support isn’t damaged. 

Before you do any of that though, what is modified bitumen roof system is? A modified bitumen roof is an asphalt-based roofing material, a close mimic of a Built-up-Roof system and is typical for a flat to low-sloped roof.  This type of roofing was started in Europe in the 1960s and spread into Canada and America in the mid-1970s. 

With 5 layers of various materials, a modified bitumen roof can withstand harsh exposure to extreme environmental and weather elements. The framework for those five layers consists of: 

  • Insulation – A high “R” value is used for temperature stability and thermal resistance.
  • Modified Base Plies – Consists of polymer-modified bitumen reinforced with plies of fabrics like fiberglass, polyester, or both.
  • Modified Bitumen Membranes – A factory fabricated co-polymer sheet membrane that is reinforced with fiberglass or polyester. 
  • Adhesive – A bonding agent and waterproof material are combined and applied either cold or hot. 
  • The Surfacing – A top layer that provides UV protection and make the modified bitumen roof weather resistant.

What is a Modified bitumen roof life expectancy? 

A modified bitumen roof has an approximate lifetime of twenty years with little to no maintenance. While a modified bitumen roof needs extraordinarily little maintenance, keeping it clean and getting repairs done as needed will give it more than 20 years life. 

modified bitumen roof

How much does a Modified bitumen roof cost?

The tangible cost of a modified bitumen roof will depend on the quality of materials, where you’re located, and any installation complexities. Estimates of a modified bitumen roof are:

  • Modified bitumen roof cost range as low as $2.50 per square foot and as much as to $4.00 per square foot for 1,500 square foot structure. This is an installed price,  the total could range between $3,750 and $6,000.
  • For the roofing contractor to remove and dispose the existing roofing,  in addition to installing the new modified bitumen roofing, the cost will increase around $6,000 up to $12,000. 

To determine Is a modified bitumen roof coating worthwhile, let’s look at some comparisons: 

Comparing a Modified bitumen vs EPDM roofing, the EPDM is a rubber membrane roofing that has an estimated lifespan of 50 years and is available in black or white. It as a strong resistance to the environment and weather and installed in one piece, it has fewer lead possibilities. The modified bitumen roof can withstand foot traffic better than the EPDM roofing and costs less than the EPDM. 

Comparing the Modified bitumen roof vs TPO, TPO is a single-ply membrane that is flexible, even in sub-freezing cold, a plus here in Maryland, and tough, withstanding hail and ice/snow weight, expanding with the temperature. Installed without plasticizers makes it a “green” option. The smooth surface makes it easy to clean, a thicker membrane makes it puncture and tear resistant, but it is more expensive than a modified bitumen roof. 

Comparing Modified bitumen roof vs shingles really doesn’t exist since a flat or low-sloped roof as most commercial structure have, shingles isn’t possible. To have a commercial structure with asphalt shingles, you would need the roof to have a minimum pitch of 2:12, meaning for every 12 inches, the roof has increase of 2 inches. The shingles would need to be adequately sealed to withstand wind lift, and special installation procedures are followed. You would also need to check with local building codes and permit. 

Choosing an experienced commercial roofing contractor is the first step. With their experience and knowledge of the industry, you can have some assurance that your commercial building and the roof are in good hands. In addition to checking their references, you  want to verify they are certified, licensed, and insured. Confirm if they pull any permits or if that is your responsibility. Call (410)-288-1633 today for your commercial roofing installation in Baltimore, MD!