The Trouble With Ballasted Roofs

Today we will tell you more about why you might need to replace a roof. There are 3 different ways to install a flat rubber roof. First is called mechanical, where you lay the rubber sheet down and mechanically fasten it to the roof around the edges. The second is called fully adhered. This is the only type of flat roof installation we will do because it is the only one we can stand behind and feel confident in. The last is the subject of today's blog article: ballasted roofs. 


Ballasted Roofs Have Limited Benefits

There is one pro for this type of roof, that is their installation price. They are cheaper than the other intallation methods because there is no adhesive used, and because the amount of time needed to install them is somewhat less. However the amount you will pay in maintenance, followed by the inevitable replacement of it far sooner than a fully adhered rubber roof would be replaced far outweigh the savings. 

Ballasted Roofs Are More Difficult to Repair

We find ourselves repairing ballasted roofs quite often, and the maintenance is slightly more difficult on them. That is because you have a sea of gravel covering them, including the spot that is leaking. We will successfully find the leak, but it will take longer to do so because we must first clear the stone and clean the rubber in suspected places before we can inspect them. 


Why You Should Replace Your Ballasted Roof

The rubber in this system is not adhered to the roof, but rather held in place by the weight of the gravel. We always find that same problem over time on theses roofs. The problem we find is that the rubber pulls away from the edges of the roof causing not just small leaks as you can occasionally expect on a fully adhered roof, but gaping holes allowing dramatic amounts of water into the building below, and possibly allowing the insulation to hold water. In the photo above we had to repair just such a problem. The reason we believe this happens is because in New England, as in most places, we go through a seasonal heating and freezing cycle. This causes the rubber to expand and contract, which is natural. However, because it is not adhered to the roof it is able to move despite the weight of the gravel. 

We believe that fully adhered rubber roofs are the only way to be sure your roof will have the longest lifespan possible with the least amout of maintenance over the course of its life. We find ourselves coming in to replace ballasted roofs quite often, and ones that aren't nearly as old as fully adhered roofs that we have installed. 

Brian Lyman