Owner's manual

Duro-Last: The Proven Performer®
"Duro-Last" and "The World's Best Roof" are registered marks owned by Duro-Last , Inc.
www.duro-last.com
800-248-0280
DATA SHEET
2009
11
DURO-LAST® STACK FLASHING
Description:
Duro-Last® Stack Flashings are required for all round
penetrations encountered on a roofing project. The
stack flashings are made with Duro-Last specially
formulated roofing membrane. The combination of
reinforced membrane and prefabrication ensures a
long lasting, watertight flashing.
Stack flashings are available in white, tan, gray and
dark gray colors. They can also be ordered with
Designer Series membrane (slate gray Shingle-Ply,
sandstone Shingle-Ply or Rock-Ply) bases and solid
color risers. They are available in diameters of 1 in.
(25 mm), 1.5 in. (38 mm) and in 1 in. increments
between 2 and 15 in. (51-381 mm). Stack Flashings
with diameters of 16 in. (406 mm) and larger are
available in 2 in. (51 mm) increments.
The flashings are manufactured oversized to account
for the thickness a schedule 40 pipe wall by the
following amounts:
• 1.5 - 4 in. (38 - 101 mm) diameter stack flashings
are 5/8 in. (15 mm) oversized.
• All other sizes are 3/8 in. (9 mm) oversized.
Installation:
1. The roof membrane installed around the
penetration must be fastened prior to installing the
stack flashing. Use the same fastener spacing that
was used to install the roof membrane but do not
exceed 18 in. (457 mm) on center. At least one
fastener must be installed. On reroofing
applications, remove the existing flashings to
ensure a watertight fit.
2. Place the stack flashing around the penetration.
Heat weld the vertical seam if the stack was
ordered “open”.
3. Weld the stack flashing skirt to the roof membrane.
Care should be taken to smooth out the skirt so
that it is wrinkle-free.
4. Apply a bead of Duro-Caulk Plus® to the
penetration 1/4 in. (6 mm) below the top of the
stack flashing.
5. Install a stainless steel band approximately 1/4 in.
(6 mm) from the top of the stack flashing. Tighten
the band to draw the flashing firmly into the sealant.
Apply a bead of the Duro-Caulk Plus® around the
top of the flashing to assure a positive seal.
6. See details 4070, 4080 and 4081 for information on
installing stack flashings to specific types of round
penetrations.
Note:
• Stack flashings and bands shall be furnished by
Duro-Last, Inc.
• Field fabrication of flashings for round penetrations
is not allowed.
• Stack flashings with diameters 16 in. (406 mm) and
larger are available "open" only.
• An "open" stack flashing requires a heat weld
(hot-air) to close the flashing. The extra material
necessary for this weld is included as part of the
stack flashing.
CLOSED
OPEN
Stack Flashing Dimensions
Diameter
Available
Height
Base/Skirt
Closed
Open
1 in.
(25 mm)
Yes No
8 in.
(203 mm)
18 x 18 in. Base
(457 x 457 mm)
1.5 in.
(38 mm)
Yes Yes
8 in.
(203 mm)
18 x 18 in. Base
(457 x 457 mm)
2 - 8 in.
(51 - 203 mm)
Yes Yes
8 in.
(203 mm)
18 x 18 in. Base
(457 x 457 mm)
9 - 15 in.
(228 - 381 mm)
Yes Yes
8 in.
(203 mm)
24 x 24 in. Base
(609 x 609 mm)
16 in.
(406 mm)
and Larger
No Yes
8 in.
(203 mm)
6 or 12 in. Skirt
(152 or 305 mm)