Modified Bitumen Roof Restoration

Modified Bitumen Roof Restoration

The Challenge

This twenty year old Modified Bitumen Roof is over a wood processing plant. As you might imagine, a leaking roof is not only inconvenient, it’s also very costly due to down time and ruined product.

The Solution

First, the contractor power-washed the entire roof surface with over 3,000 psi to ensure the roof coating system would adhere to the aged and worn roofing material. Before the system was applied, a moisture survey was completed to ensure the roofing substrate and insulation were dry. If wet insulation is found, it must be replaced before the roof coating system can be installed.

After a thorough cleaning, the contractor applied one coat of Acrylic Bonding Primer 905. This was done to ensure proper adhesion of the butyl coating system to the roof substrate. Other suitable primers include Fabric Bond 930 and SBS Primer 950. 

Once priming was completed, the waterproofing stage began. Every seam, penetration, and transition was covered with polyester fabric and Butyl 310. A base layer of Butyl 310 was then applied to each seam. Then fabric was laid into the coating, and finally sprayed with another layer of Butyl 310.

Since this particular roof had aged to the point where leaks were throughout the entire roof, the next step was to apply fabric and Butyl 310 to the affected areas. In many circumstances, the contractor may install a full fabric system over entire roof.

After fabric was installed in all the areas of concern, the entire roof was sprayed with two more coats of Butyl 310 to form a seamless, elastomeric membrane over the entire roof. Other appropriate top coats for this type of application include Urethane 520, for low slope applications that do not drain well, or Acrylic 211, in situations where the roof does drain well.

The Benefits

The primary goal of this restoration project was to prevent leaks that were ruining product and forcing down time. The combination of butyl and fabric was able to stop the roof leaks, which allowed the wood processing plant to increase production.