Print Friendly, PDF & Email

Weighing in on Ballasted Roof Systems: Costly Issues You Need to Understand

Ballasted roof systems are simultaneously a roofer’s best friend and arch nemesis. Simply put, a ballasted roof is easy to install and basically guaranteed maintenance work for a roofer. Somebody walking on the roof will undoubtedly step on the ballast and put a hole in the membrane. Holes mean roof leaks and roof leaks mean call the roofer. Thanks best friend!

Enter arch nemesis. Roof leak investigation on a ballasted roof can be a bit of a nightmare. Ballasted roof systems hold dirt and dust in between the stone which makes finding small punctures very difficult. Plus, the only way you’re able to see the membrane is to move the ballast. That means somebody (Mr. Roofer) is shoveling stone out of the way.

This all takes time and costs the building owner more money.

Ballasted roof system

Ballasted roof system.

When you are considering a new roof system ballast can be a good way to save money on the install but there are costly disadvantages to this sort of system.

Repairs to Ballast Roof Systems

Area of ballast removed for roof repair and not replaced.

Ballast removed from area of roof for repair and not replaced.

As I mentioned earlier ballasted roofs can present certain challenges for a roofing contractor when attempting a repair. In order to locate the roof leak source the ballast stone needs to be moved to access the membrane below.

One of the biggest issues we see with repairs to ballasted roof systems is contractors who do not replace the ballast to the area after removal for repairs.

So what happens when the ballast isn’t put back in place? In order to understand why this is such a big problem let’s go over how a ballasted roof system works.

Looking for a good contractor to help repair leaks on your ballasted roof system?

Trust the roof leak experts at Jurin Roofing Services to repair your roof leak properly.

Contact us today!
Contact us today!

Anatomy of a Ballast Roof System

  • The stone ballast on a ballasted roof system is the only thing holding the roof system in place.
  • The insulation is loose laid onto the decking. There are no fasteners installed at all (3 and 4).
  • Next the membrane is rolled over the insulation (2). This again is loose so there are no fasteners or glues used to hold it down.
  • Stone is then distributed over the entire system to weigh everything down (1).
Area of ballast removed for roof repair and not replaced.

Ballasted roof system illustration courtesy of Carlisle SynTec.

When the stone is removed for leak investigations or penetration installs, that area becomes susceptible to wind uplift. The insulation can then be shuffled and stacked under the membrane.

Check out the below video to see what happens to a roof when ballast is removed and not replaced.

Once the roof has gotten to this point you’ll be contacting Mr. Roofer once again to come out and repair the problems caused by the repair. The roof membrane has to be removed, the insulation repositioned or replaced, new membrane installed and tied into the existing membrane. Now you are paying twice for one repair.

ALWAYS make sure your roofing contractor redistributes the ballast after repairs are made.

Roof Damage from Foot Traffic

Another costly issue with ballast roof systems is that people accessing the roof tend to walk directly where they need to go and ignore walkways.

Stepping directly on the stone ballast can result in excessive pressure pushing the stone into the membrane and creating a slice or hole.

While they may not always be convenient, walkways are definitely there for a reason. This expense is one that is easily avoidable. Make sure that anyone accessing your roof is directed to stay on the walkways to protect the membrane underneath.

Walkway on a ballasted roof system.

Walkway on a ballasted roof system.

Ballast Stone Breakdown

Close up of ballast sharding.

Close up of ballast breaking down, also referred to as sharding.

The last way ballasted systems can create higher repair bills is from stone degradation. After years of weathering and being walked on the stone will start to breakdown and actually split.

What started out as nice, smooth, round stone ends up sharp and jagged. These sharp edges are perfect for slicing the membrane the next time someone steps on them.

These sharp edges are perfect for slicing the membrane the next time someone steps on them.


As you can see, cheap to install doesn’t necessarily mean cheap to own. Sometimes spending a little more up front can actually save you more money in the long run. There’s a lot more that should go into a roof system design decision than just a lower price point. There are better methods to help you save money on your roof installation cost.

After all, less issues and less roof leaks means less repairs which means less money spent and probably a lot less headaches.

Contact Us

Planning a new roof installation and wondering which roof system is right for your building? Contact Jurin Roofing today and we can help you design the perfect roof system for your budget and building.

Founded in 1974, Jurin Roofing Services, Inc. is known for top quality roofing throughout the east coast. Jurin Roofing Services is a full-service commercial roofing contractor offering roof maintenance, roof and leak repair, and roof replacements. Jurin Roofing Services also offers professional roof services such as roof inspections and infrared roof moisture scans. Jurin Roofing is also a member of the National Roofing Contractors Association (NRCA) and is a Carlisle SynTec Hall of Fame and ESP (Excellence in Singly Ply) contractor.
Contact Us

Related Articles