left it intact, as it would ultimately serve as
the substrate for the polyurea application.
a straight spray edge when it came time
to do the application.
The workers employed three power-washers
to clean the roof, running water lines from
down in the mechanical room. Then, leaks
on the existing roof were patched with
Firestone cover strips.
“You can have a ragged spray edge that will
be just as effective as a nice straight line,”
said Wagoner. “But when the owner comes
on the roof, if it looks sloppy, you look
“You want the rubber to be leak-proof
before you start putting on the new stuff,”
said Wagoner. “If there are any holes, they all
have to be sealed with the proper materials,
then the polyurea goes over all of that.”
The roof was then primed with Techno
Adhesive 199 with a Titan 540 sprayer in
preparation for the polyurea application.
According to Wagoner, it is one of the
few primers that “bite” into old rubber
In anticipation of windy conditions on
the roof, an engineer who worked for WRI
developed a half-dome spray booth that
crewmembers could stand in while spraying.
The spray booth was made of PVC pipe
wrapped in burlap.
“It was light enough for two guys to move
while one guy was spraying,” said Wagoner.
“The crew jokingly referred to it as ‘the
(cont’d on the next page)
Crewmembers were careful to mask off
lower areas of the roof in order to create
SPRAYFOAM insulation & roofing MAGAZINE 29