SECTION 07550
MODIFIED BITUMEN MEMBRANE ROOFING (SBS)
Modified Bitumen Membrane Roofing (SBS)
UIHC #20X-0XX 07550-11
3.07 APPLICATION OF MODIFIED BITUMEN SHEET (REROOFING)
A. Apply base ply over substrate as recommended by the membrane manufacturer. Reference
Section 07220 - Roof and Deck Insulation for installation requirements of roof insulation.
Apply bitumen at the coverage rate and temperature as recommended by the manufacturer.
B. Phased application is not permitted. All plies shall be completed each day.
C. Application of base ply should result in a smooth even substrate in order to firmly bond
membrane onto.
D. Align base plies so manufacturer's minimum specified end and side laps are maintained.
E. When base ply has laying lines, the lines shall be used to position the subsequent plies for
compliance with nominal lap requirement. For products without laying lines, conform to
manufacturer's lap requirement.
F. Should misalignment of the sheet occur during application causing a variation from minimum
lap requirements, the sheet should be cut and realigned to satisfy minimum lap requirements.
G. Clean and prepare base-ply for application of finish-ply membrane.
H. Apply finish-ply membrane over base-ply as recommended by the membrane manufacturer.
I. All layers of roofing shall be laid free of wrinkles, creases or fishmouths and shall be laid at
right angles to the slope of the deck so the direction of flow of water is over and not against
the laps.
J. Sheets shall be laid directly behind the torch applicator.
K. Sufficient pressure shall be exerted as recommended by the membrane manufacturer on the
roll during application to ensure prevention of air pockets, and proper embedment.
L. Lap base ply and surface membrane the minimum distance as recommended by the membrane
manufacturer.
M. Stagger laps between the plies so the base-ply lap is not within two inches of the finish-ply
membrane lap.
N. During inspection if there is insufficient lap width, a membrane strip no narrower than twice
that of the required lap shall be installed over the deficient lap using the appropriate
attachment method.
O. Torching
- Follow the owners requirements for fire safety and permitting system. See Section
00441.
November 1, 2016
