Surface Preparation

New concrete must be a minimum of 7 days old Surfaces to be applied upon, must be clean, reasonably dry, free form dirt and loose material, and conform to the agreed minimum surface standard. All voids and pinholes shall be filled using polymer modified mortar Brick parapet walls should be rendered by the Main-contractor. The render should be smooth, free from voids and pinholes

Laying Screed to slope

The concrete screed of M20 grade shall be laid to desired slope (1:100) over the RCC roof slab in accordance with standard concreting practices. The change in the slope to create a camber shall be achieved as per the instructions from the engineer in-charge. The location and size of rain water pipe shall be as per the drawing and must be ensured prior to start of waterproofing work. The screed shall be cured for a minimum of 14 days. The standing water then shall be removed and surface shall be allowed to dry. Alternatively, the slope also can be created in Brick Bat Coba / Lime Concrete, etc., 100 mm x 100 mm angle fillets (corner rounding) of non-shrink mortar should be placed at the intersection of all vertical and horizontal surfaces for the waterproofing membrane to turn up.

Primer Application

Apply solvent-based bitumen primer on cleaned concrete surface @ 3-5 sq.mtr/ltr. The priming will enhance the adhesion of the membrane to the substrate. Allow the primer coat to dry. The drying will generally depend on the ambient temperature

Membrane Application

Starting at low point from the roof, unroll the DR. FIXIT TORCHSHIELD P4160 roll once the priming coat is dried. Align the DR. FIXIT TORCHSHIELD roll correctly & re-roll it half in alignment before torching. Avoid shifting of the membrane while torching Use gas burner to heat substrate & underside to softening points. When the embossing disappears, roll forward & press firmly against substrate to bond from the lower end towards the higher end. Ensure sufficient bleed on side & end over laps. Once the half of the roll is torched properly to the substrate, unroll the balance roll and repeat the process.
An overlap of 100-mm shall be maintained for all the continuing sides. Heating shall be done on both the membranes to be overlapped and pressed firmly with the help of round shape trowel. The care shall be taken to leave no gap at any point in the overlapped area. If noticed, reheating shall be done to seal it.
In case of open drains running along the slab for water to get collected and then drained out through a down take pipe, the size and shape of the drain should be sufficient to allow the laying of Torchshield in the drain. In such case, the rectangular corner of screed and drain shall be chamfered for membrane to take smooth curve inside the drain. The membrane shall be screwed with GI screws to the drain wall along with aluminium or GI strip.
The drain shall have an adequate slope towards the down take pipe (1:100), the same shall be ensured before starting application of Torchshield.
In case of inadequate drain size (for fixing the Torchshield), the waterproofing of drain section shall be done with Dr. Fixit Proofcote Black, which is a polymer modified bitumen based cold applied waterproof coating. Apply 3 coats to cover the entire drain section and overlay 20 mm thick mortar to protect it. The plaster shall be finished smooth and cured for 7 days.

Clean & remove dust, dirt, loose particles and unsound substrate	Apply primer coat with solvent based bitumen primer	Unroll the DR. FIXIT TORCHSHIELD roll
Align the Dr. Fixit Torchshield Roll	Use gas burner to heat substrate & underside to softening points	Keep overlap margin for minimum 100 mm
Heat both the overlaps & use round tipped trowel to seal overlap	Seal the edges well and protect with a Polysulphide sealant	Dr. Fixit Torchshield applied all over the terrace

Termination of Membranes

The membranes shall be first laid up to the parapet wall junction and then shall be overlapped with another membrane (flashing) with an overlap of 100 mm and taken upward on the parapet wall up to a distance of 300 mm. This overlap shall be firmly sealed over the corner rounding or fillet area at the junction of parapet wall and slab The rendering shall be done above this level till top of parapet wall to match the level of membrane and drip mould shall be created in the plaster at the place where membranes is terminated to drift the rainwater away from the membrane. Alternatively an aluminium or G.I. sheet flashing can also be fixed over the membrane, fixed with GI screws with the parapet wall. (Refer sketch for details)

At the opening of Rain water pipes

The places where opening are encountered for rain water down take pipes, the membranes shall be cut open by sharp knife in + sign in the center of an opening. Circular cutting shall not be done. Torching shall be done on the reverse side of these four triangular pieces. Bend all the four pieces inside and tightly pressed against pipe surface.

Termination At The Expansion Joints

The treatment shall have to terminate at the expansion joint. The curb wall of 4 inches thick shall be constructed on both sides of joint. The height of curb wall shall match the overall height after filling of soil. The curb wall shall be plastered smoothly and corner rounding with polymer-modified mortar shall be done before membrane applications starts. The final slope of screed shall be away from the joint. The joint shall be covered either with GI strip fixed on one of the curb walls while leaving other end free or by neoprene sheet.. The expansion joint shall be filled with 2 part flexible Polysulphide Sealant from the Dr. Fixit Range in accordance with the product specifications.

Protection

The Torchshield membrane shall be protected with cement sand mortar laid at 20 mm thickness. The curing of this mortar shall be done for a minimum of 7 days before filling of soil for gardening. Anti root treatment: suitable anti root treatment shall be provided over the mortar as per the consultants specification.