To the right is the hospital. Originally protected by reinforced asphalt membranes, adhered to concrete roof decks, all of the roof planes were recovered, about 27 years back, using synthetic rubber membranes. In place of costly replacement, Waterbarriers has been, section by section, restoring the flashings of each, beginning in 2013. We estimate having conserved about $2.5 MM dollars of owner capital, compared with replacement costs. Protected by Carbon Black pigmentation, the field sheets of synthetic rubber just do not wear out, only the wall and penetration flashings need periodic preventive maintenance, on a basis of decades. Others would have sold the owner unneeded new roofs.
Seen here is the rubber field sheet drawn over the drain bowl. The slits were cut by us in preparation for removing the old sheet, from around the drain, itself.
The four bolts that hold down the drain clamping ring, typically rust in place and ring off. We drill them out and cut fresh threads into the drain body. Then, the bowl is cleaned within an inch of its life, back to green metal and painted.
Per industry guidelines, a new rubber "Target" has been placed over the drain bowl and adhered in place. At the target's perimeter, additional securement has been added. This drain, fully rebuilt, is now a low point in the roof plane, withdrawing all of the water.
Bulging may be seen at the base of the walls, caused by shrinkage within the field. Rubber roof membranes lose size during their first seven years, creating enough stress for pulling off the wall flashings. Tenting is very simple to rectify.
The old wall flashings were sliced and allowed to relax, followed by mechanically re-attaching them at the transition from vertical to horizontal. Lastly, new membrane is adhered onto the wall face in order to re-seal the lengthwise slit.
Pictured here are two stainless steel laboratory exhaust penetrations, beautifully re-flashed.
When restoring an asphalt-based roof, compatible asphalt products must be utilized. Unfortunately, the owner chose price over quality and received prematurely failed Terpolymer Olefin, single reinforcement sheet, as a result.
Since before 2013, the owner had engaged for spot repairs, only. Yet the root cause of water infiltration had not been fully identified. The spot repairs were as numerous as the stains on the ceiling tiles, inside.
Unreasonable access to the roof surface had long ago made repairing leaks a very difficult, if not impossible, affair. Its weight created pooling towards the rear of the building.
To the benefit of key personnel, Brokers and Managers, we perform a comprehensive Roof System Condition Evaluation report for review, which aids them through the decision making process. It is essential to give sufficient objective data so that an informed decision could be made. A number across the bottom of a sheet of paper does nothing to enlighten the responsible parties.
Our reinforced asphalt membranes are formulated to our specifications. In place of mineral granules, our rolls are finished using slate chips. Slate chips retain a porosity that enhances their adhesion to asphalt surfaces.
The finished, monolithic product is straight, proportional and pleasing to the eye. Installed cost, not including equipment removal: $2.86 per S. F.
© 2018. Andrew D. Knapp