Instructions / Assembly

5
6. Removing all wet roof insulation and old, wet membrane.
Replacing with dry materials. The existing roof membrane must be
in a condition suitable to receive the new roof assembly.
Note: It is highly recommended that a moisture survey be made to deter-
mine the extent of wet insulation and moisture entrapment.
7. Providing for proper drainage of the new roof system to eliminate
ponding. Provisions must be made to ensure the new roof system
has proper drainage, i.e., placement of additional roof drains, use
of tapered insulation, use of crickets, etc., as appropriate.
8. Complying with all code requirements.
9. GAF recommends re-covering over only one existing roof system.
GAF will not issue a guarantee for a new GAF roof membrane
installed over more than one pre-existing roof system.
Re-cover Specifications
GAF requires that the new roof membrane be separated from the old
roof system by the installation of a layer of EnergyGuard
™
Polyiso Roof
Insulation. The maximum insulation board size is to be 4' x 4'
(1.22 m x 1.22 m).
Specific Deck Requirements: Steel, Gypsum, Wood, Tectum
1. Any gravel surfacing must be removed to provide a smooth surface.
2. On smooth-surface roofs, the old roof surface should be level
and clean.
3. Remove all wet or damaged roof insulation and old, wet membrane.
Replace with new insulation of the same type and cover with new
membrane to complete the repair.
4. Old membrane must be cut on 3' (914 mm) centers to allow for the
release of any trapped vapor pressure.
5. Re-covering over existing modified bitumen smooth and granule-
surfaced roof systems requires the use of a mechanically attached
insulation.
6. When insulation is used, it must be mechanically fastened with Drill-
Tec
™
Fasteners to steel decks. On tectum and gypsum decks, after
removing any gravel, new insulation can be mopped to achieve a
minimum of 70% attachment. The surface of the old BUR roof sur-
face must be primed before mopping in the insulation. Install new
roof specification to insulation as outlined in this manual.
7. Top side venting is required. Use vent stacks installed at the rate of
one per 1,000 square feet (92.9 m) or use perimeter venting.
8. All specification requirements and recommendations listed in this
manual must be followed, i.e., slope, nailing, etc.
9. If the old roof is a coal tar BUR, a mechanically fastened insulation
must be used. Proper precautions must be taken to ensure that coal
tar drippage into the building does not occur.
COLD WEATHER APPLICATIONS
Special care is necessary in applying Tri-Ply
®
Membranes at temperatures
below 45 °F (7.2 °C). The roof surface must be ice-free and dry.
Tri-Ply
®
Membranes must be stored for at least overnight at a minimum
of 55 °F (12.8 °C) prior to their application. For mop-applied Tri-Ply
®
Membranes, asphalt must be at least 425 °F (218 °C) (with a target
temperature of 425 °F [218 °C]) or ±25 °F (±13.9 °C) above the EVT,
whichever is higher, at the point of application. Mopping must not
precede the roll by more than 5' (1.52 m).
For both mop-applied and torch-applied Tri-Ply
®
Membranes, the rolls
must be at least 45 °F (7.2 °C) at the time of application.
TRI-PLY
®
Design and Application Instructions
TRI-PLY
®
BUR
INSTALLATION INSTRUCTIONS
Tri-Ply
®
BUR Granule Cap Sheet is considered part of the membrane
system as well as surfacing. The application of Tri-Ply
®
BUR Cap Sheet
shall commence at low points of the roof so that at no place is the
flow of water against the laps. Parallel lap lines of cap sheet should
not coincide with the lap lines of the underlying piles wherever
possible. Application must be over and parallel to the underlying
roofing membrane.
All sheets must be precut into 10' to 12' lengths (3.05 – 3.66 m) and
stacked prior to application. Sheets may be cut in 15' to 18' (4.57 –
5.45 m) lengths if the temperature is 65 °F (18 °C) or above. Embed cap
sheet in steep asphalt applied at the nominal rate of 25 lb (11.3 kg) per
100 square feet (9.2 sq. m). Side laps must be a minimum of 2" (51 mm)
and end laps 6" (152 mm). End laps shall not occur in a continuous line
and should be broken by a minimum of 3' (0.9 m). Uniformity of the
separation of side laps is desirable for best appearance. All sheets must
be firmly embedded in the hot asphalt and be free of wrinkles, buckles,
blisters, fishmouths, or voids.
End laps must be nailed on all slopes exceeding 1:12.
There are three acceptable methods of application:
1. The “flop in” method involves setting the precut sheet with
mineral-surfaced side down adjacent to the area where it is to be
applied with the lap of the previous course exposed. Solidly mop
with roofing asphalt the full sheet width to be covered including
the lap. The Tri-Ply
®
BUR Cap Sheet should be picked up at each
end and at the outside edge, turned over, and set immediately into
the hot mopping.
2. The “fly in” method involves mopping the full width of the area
to be covered and then picking up a precut sheet and setting it
immediately into the hot mopping.
3. The “reroll” method involves setting the precut sheets so it is in
its exact final position, rerolling it, and then mopping immediately
ahead of the roll as it is rolled in place.
Note: Brooming of the Tri-Ply
®
BUR Cap Sheet is desirable in all cases to
ensure completed adhesion. Also, in the “flop in” and “fly in” methods,
tension should be placed on the precut sheet as it is being set to avoid
wrinkles or buckles in the sheet.
Application of the Tri-Ply
®
BUR Cap Sheet at temperatures below
50 °F (10 °C) is not recommended. At temperatures near 50 °F (10 °C),
the reroll method with complete brooming will provide the best results.
Wind conditions, which may chill the asphalt more quickly, must
be considered.