Instructions / Assembly

TRI-PLY
®
Design and Application Instructions
TRI-PLY
®
SBS INSTALLATION INSTRUCTIONS
TRI-PLY
®
SBS MEMBRANE INSTALLATION
1. For slopes less than ½:12, Type III or IV asphalt can be used.
Type IV must be used on all slopes ½:12 and over.
2. Asphalt shall be applied at its EVT temperature or 425 ˚F (218 ˚C),
whichever is greater, in a uniform layer, without voids, at a rate of
25 lb/square (1.2 kg/m²) ± 20%.
3. For mop applications of Tri-Ply
®
SBS Membranes, the mopping
stroke will be such that the side lap is covered with asphalt last.
A rolling bank (puddle) of mopping asphalt must be maintained
across the full width of the roll.
4. Cap sheet application: Install full-width cap sheets, lapping 3"
(76 mm) on the sides and 6
"
(152 mm) on ends. Stagger adjacent
end laps a minimum of 18" (457 mm) apart. All side and end laps
must be staggered from underlying plies.
5. All laps must be parallel or perpendicular to the slope of the roof
such that the flow of water is never against the lap.
6. Tri-Ply
®
SBS Membranes must not be applied during adverse
weather or without precautionary measures in temperatures
below 45 ˚F (7.2 ˚C).
7. Coiled rolls should be unrolled, placed upside down, and allowed
to “relax” prior to installation. Then reroll to apply. Care should be
taken to ensure that the cap sheet lies flat in the asphalt. There must
be complete adhesion between the cap sheet and the mopping
asphalt. Brooming-in may be necessary under certain conditions
to ensure that the cap sheet adheres solidly to the asphalt. Apply
extra pressure to avoid creating open channels where three or more
membranes are lapped.
8. A minimum 3/8" (10 mm) asphalt flow-out must be obtained at all
laps. Dry laps are not acceptable. Check all seams for full and
uniform adhesion.
9. All end laps must be staggered a minimum of 18" (457 mm) so
that no adjacent end laps coincide. If end laps fall in line or are
not staggered the proper distance, a full width of Tri-Ply
®
SBS
Membrane must be installed over the end laps.
10. For additional information and requirements, contact GAF Technical
Services at 1-800-766-3411.
FOUR (4) PLY SBS HOT-MOPPED SYSTEM
NAILABLE DECK
BASE/INTERPLY SHEETS – MECHANICALLY FASTENED
After allowing the base sheet to relax, keep sheet taut, fastening at center
of sheet and working in opposite directions. Push all wrinkles and buckles
ahead as fastening proceeds.
The following are minimum fastening patterns that may be used when
fastening the base ply:
1. Base sheet (no insulation) on decks of wood, plywood, OSB, light-
weight concrete, gypsum, or cementitious wood fiber.
a) Lap the base sheet 2" (51 mm), and mechanically fasten with
three rows of fasteners. The first row (on the seam) will be
1" (25 mm) from the leading edge and on 9" (229 mm) centers.
Locate the second row of fasteners 14" (356 mm) from the
leading edge and on 18" (457 mm) centers. The third row of
fasteners shall be 26" (660 mm) from the leading edge on
18" (457 mm) centers. The centers for the second and third
rows should be staggered.
b) Plywood or OSB decks only. Lap the base sheet 2" (51 mm) and
mechanically fasten with four equally spaced rows of Senco
Tape and N12 BAB or N12 FAB Staples spaced at 9" (229 mm)
o.c. centered over the 2" (51 mm) wide laps and at 9" (229 mm)
o.c. in three rows equally spaced in the field of the sheet.
2. Simultaneous fastening base sheets with insulation, with the
fasteners having a 3" (76 mm) plate.
a) Lap the base sheet 2" (51 mm). Screws and plates are then
installed in 3 staggered, equally spaced rows on 24" (610 mm)
maximum centers in each row. One row is in the 2" (51 mm)
side lap, the other rows are located equidistant from the lap
rows approximately 12" - 13" (305 - 330 mm) from the lap rows.
This pattern results in approximately one fastener per 2.1 square
feet (0.20 m²). Along building perimeters (minimum 4-foot
[1.22 m] wide) fastening pattern must be increased to one
fastener per 1.2 square feet (0.11 m²), in 4 staggered, equally
spaced rows of fasteners on 18" (457 mm) centers.
Note: When fastening base sheets using screws and plates without
insulation or over DensDeck
®
, the plate must be of a design that allows it
to lie flat on the deck.
Tri-Ply
®
Ply 4
Tri-Ply
®
BUR Granule
Cap Sheet
Tri-Ply
®
#75
Base Sheet
7