The surface shall be cleaned thoroughly of all contaminants
like dust, traces of curing compound, oil and grease. All
surface imperfections, protrusions, structurally unsound
and friable concrete must be removed and repaired with a
suitable Polycrete* concrete repair mortar.
Apply Polyprime SB* (Solvent based primer) @ 4- 6 m²/L
to a clean smooth and dry surface by brush, roller or
spray. Allow the primer to dry prior to the application of
the membrane. As the viscosity of the primer is low, it can
easily penetrate into the concrete pores and promote the
adhesion between the membrane and the concrete surface.
In addition to that the primer also acts as a binder for the
dust particles which gets accumulated on the concrete
surface even after cleaning.

Start the installation of all membrane plies at the low
point or drains, so the flow of water is over or parallel to
the plies, but never against the laps. All overlaps at the
membrane seams shall be installed so as to have "up" slope
laps over "down" slope laps. Begin membrane application
by unrolling the roll of Bituplus G 4200 membrane and
aligning the side laps. Re-roll the roll halfway and stand
on the unrolled portion to prevent shifting. Side overlaps
should be a minimum of 100 mm and the end overlaps
150mm.
BITUPLUS G 4200 membranes are installed by using a
cylinder fed propane gas torch. Use of handheld roofing
torch is recommended as it affords a good control. If
multiple burner torching machines are utilized, care must
be taken to ensure the application of uniform heat and
avoid overheating of the membrane. Begin torching the
embossed polyethylene side of the rolled portion of the
membrane. Proper torching procedure involves passing the
torch flame in an ”L” pattern applying about 75 percent
of the heat across the coiled portion of the roll and 25
percent across the substrate, including the lap area of the
previously installed membrane. As the membrane is heated
the embossing starts to melt away exposing a shiny bitumen
surface. Roll forward the membrane and press firmly with
the boot or roller against the substrate to bond well. The
propane flame should be moved from side to side and up
the lap edge while the membrane is slowly unrolled and
adhered to the underlying surface. Subsequent shift of
the roll shall be avoided after heating has begun. When
complete, the remaining untorched membrane shall be
re-rolled and installed in the same manner. When one
end is complete, re-roll the opposite end not yet torched, and install in the same manner 

All angles and abutments should be sealed with extra care
to ensure full bonding. Bituplus G 4200 shall be lapped
with the base membrane and taken up on the parapet wall
and tucked into a groove cut into the concrete.The grooves
shall be sealed with a suitable mastic sealant (Bitumastic).