1: Surface Preparation
Description:
Surface Preparation: Cleaning of the surface, treating of construction joints, filling of honeycombs, etc. of slab to be carried out before executing waterproofing treatment.
Procedure:
- Thoroughly clean the concrete slab surface to remove all dust, dirt, oil, grease, loose particles, and debris using a wire brush, mechanical grinder, or compressed air. Ensure the substrate is sound and free from laitance or contaminants that may hinder adhesion.
- Identify all construction joints. Open and clean the joints as needed, ensuring proper preparation for joint treatment. Repair by filling with appropriate polymer-modified mortar or an approved sealant system, as per technical recommendations, to restore integrity and prevent leakage.
- Locate all honeycombed or deficient areas in the slab. Remove any loose or unsound concrete from these zones. Fill the cavities with suitable polymer-modified mortar, such as one prepared with Futurelayer’s recommended SBR LATEX (Styrene-Butadiene latex), which enhances bonding and waterproofing capabilities, as per the product’s data sheet.
- After all repair works, visually inspect the prepared surface to ensure it is uniform, free from undulations, and ready for further stages of the waterproofing treatment.
- All surface preparation activities must be completed and thoroughly checked before executing any waterproofing application, in line with project specifications and technical data sheet guidelines.
2: Primer Application – Futurelayer’s recommended Pu Primer
Description:
After Cleaning of the Surface and Treating of construction joints etc., Primer will be applied before applying waterproofing liquid membrane.
Procedure:
- Ensure the surface is dry, dust-free, and sound after cleaning and treating all construction joints.
- Mix the Futurelayer’s recommended Pu Primer thoroughly using a slow-speed stirrer (450–600 rpm) until a uniform consistency is achieved.
- Apply the primer uniformly to the prepared concrete surface by brush, roller, or airless spray at a coverage rate of approximately 8–10 m²/L per coat, achieving 40–50 microns DFT, depending on surface porosity.
- Allow the primer to become touch-dry (about 35–45 min at 30°C) before proceeding with the next step. Make sure the surface is tack-free and ready for membrane application.
- Use all mixed material within the recommended pot life and never return unused material to the original container.
3: Polyurethane Liquid Membrane – Futurelayer’s recommended Pu Non Uv 1K
Description:
Over above the primed layer, provide and apply a waterproof membrane of liquid, of pure polyurethane based, single component, low VOC, elastomeric, seamless & having solid content 90% (as per ASTM C836), elongation at break of 400%. The membrane to be applied with a brush/roller in 2 coats to achieve a DFT of 0.70mm (consumption @ 1.0 kg/sqm).
Procedure:
- Stir the Futurelayer’s recommended Pu Non Uv 1K thoroughly using a slow-speed mechanical stirrer to obtain a homogeneous mix. Allow entrapped air to escape before use.
- Immediately after priming, apply the first coat of Futurelayer’s recommended Pu Non Uv 1K with a brush, roller, or airless spray while the primer is still tacky.
- Lay the membrane in two coats, each at 0.35 mm to achieve a total DFT of 0.70 mm. The waterproofing layer should be seamless, elastomeric, and meet ASTM C836 standards, with elongation at break of 400% and solid content of 90%.
- Allow the first coat to dry for 10–12 hours before applying the second coat. Avoid application during rain or when the surface temperature is below 4°C or above 40°C.
- Upon completion, allow the final coat to cure for a minimum of 36–48 hours before exposing the surface to physical protection measures or other construction activity.
4: Spray Polyurethane Waterproofing System (Futurelayer’s recommended PUF)
Description:
Applying over the cleaned surface instant setting spray polyurethane waterproofing system of 10 mm thickness with a density of minimum 55 kg/m³, having fire resistance property confirming to class B2 as per DIN 4102; having min 96% closed cell content of approved make and as per the manufacturer’s recommendations.
Procedure:
- Ensure the surface is dry, sound, and free from grease, oil, curing compounds, and contaminants to ensure optimum adhesion of Futurelayer’s recommended PUF.
- The substrate temperature must be above 10°C and the moisture content below 5% (relative humidity not exceeding 80%).
- Use a two-component spray machine with material preheating (40–70°C) and delivery hose arrangement.
- Mixing pressure should be 1000–1500 psi for optimal mixing.
- Begin spraying PU PUF in layers, each with a thickness of 10 mm (multiple passes may be used to reach required thickness).
- Allow each layer to cure before subsequent application per the manufacturer’s intervals.
5: Spreading Geotextile 150 gsm (Futurelayer’s recommended Non-woven Polyester)
Description:
Over the above membrane, Geotextile 150 gsm (non-woven polyester) to be spread.
Procedure:
- Ensure the waterproofing membrane application is fully completed and cured per manufacturer’s instructions.
- Remove sharp projections, dust, water, and debris.
- Use approved 150 gsm non-woven polyester geotextile rolls. Inspect rolls for tears, holes, or defects.
- Unroll and spread the geotextile carefully and evenly; overlap sheets by at least 75–100 mm, staggering end laps.
- Secure for vertical/inclined surfaces as needed.
6: Laying M20 Screed & SRI Coating/Glass Cloth
Description:
A layer of 60mm avg. thick M20 grade screed to be laid with required slope all around on the roof/terrace. At the parapet wall junction, an angular fillet of 50 mm x 50 mm to be provided of cement-sand mortar in 1:3 proportion, including applying a coat of SRI Coating reinforced with glass cloth reinforcement at the joint of angle fillet and screed.
Procedure:
- Ensure the geotextile and preceding works are done and surface is debris-free.
- Prepare and lay M20 grade screed (avg. 60mm thick) with required slope for drainage.
- Construct a 50×50 mm angular fillet at all parapet wall junctions using 1:3 cement-sand mortar. Compact and finish fillet.
- At the joint between fillet and screed, apply SRI coating (Futurelayer’s recommended SRI Coating) and embed glass cloth for reinforcement.
- Allow screed and coatings to cure as per manufacturer’s recommendations before further works.
7: Cutting Grooves & Joint Sealing
Description:
The concrete shall be exposed by cutting grooves of size 6mm (W) x 35mm (D) by saw cutting into panels of size 2.5 x 4m, the grooves shall be filled with Futurelayer’s recommended Bituminous sealant.
Procedure:
- After screed has cured, mark and cut panels of 2.5 x 4.0 m.
- Saw cut grooves 6 mm wide by 35 mm deep as per marking.
- Remove all debris from grooves.
- Fill with approved bituminous joint sealant, ensuring watertight joints.
8: Fibre Reinforced Acrylic High SRI Coating Futurelayer’s recommended SRI Coating
Description:
Over above the screed concrete, apply fibre reinforced water based acrylic waterproofing cum high SRI value of 99, in two coats with a roller/brush at consumption of 1 litre/sqm.
Procedure:
- Ensure screed is fully cured, dry, and free from dust, oil, and laitance. Repair cracks and joints with Futurelayer’s recommended SBR Latex polymer-modified mortar.
- Primer/Self-priming: Dilute Futurelayer’s recommended SRI Coating (or equivalent) with 50% water. Apply by roller or brush as primer and allow to dry for 3–4 hours.
- Apply the first undiluted coat uniformly. Allow to dry 4–6 hours.
- Apply a second undiluted coat perpendicular to the first. Maintain consumption of at 1 litre/sqm after curing. Allow to dry 4–6 hours more.
- Prevent contact with water/rain until full curing (min. 48 hours). Do not apply below 10°C or in wet conditions.