In the majority of construction uses, terrace tiles are assumed to bar water. Tiles and grout, though, are usually not enough to bar moisture, especially under pressure, with age, or with fissures. That is where a product like SANIFLEX‑Universal shines.
Why Roof Waterproofing Behind Tiles Matters?
Tiles are solid facing surfaces. They waterproof the substrate to some extent — but:
Grout and joint areas are permeable. Good quality grout contains small pores within it and will soak up water or allow the passage of dampness by diffusion over time, especially under cyclic stress.
Substrate movement leads to cracking. Tiles will, over time, expand, contract, and shift slightly, leaving small cracks in the underlying concrete or mortar. They provide a path of access for water into the building.
Water from the exterior can push against the substrate from the reverse side, e.g., areas of dampness, and fill in compromised areas.
Without effective roof waterproofing membrane protection, water entering behind the tile can get trapped, resulting in delamination, efflorescence, mold growth, or finish damage.
Introduction to SANIFLEX‑Universal: What it Does & Why it Works
Aquafin Pakistan offers SANIFLEX‑Universal as an elastomeric roof waterproofing coating with several advantages.
Elastomeric & Crack-Bridging
SANIFLEX-Universal has good recovery and elongation properties, thus it can accommodate slight movement of substrates and bridge hairline cracks.
Good Adhesion & Substrate Compatibility
It has good adhesion on porous and non-porous concrete or masonry substrates.
Breathability / Vapor Permeability
Because it forms a waterproof membrane, it allows the cementitious substrate to "breathe," so moisture vapor pressure is not entirely trapped behind the membrane.
Decorative & Protective
The coating provides a better aesthetic look to the surface and is also a protective layer against environmental attack (chlorides, CO₂, acid gases) on exposure.
UV Resistance, Freeze/Thaw Durability
It remains stable when exposed to UV and is resistant to cyclical freeze-thaw stresses, which is a benefit for exposed or partially exposed installations.
Application-Friendly
It can be applied brush, roller, or by spray, and is available for use internally or externally below or above screeds.
Barrier against Aggressive Components
SANIFLEX‑Universal offers resistance against chlorides conveyed in water, carbonation, gas penetration, etc.
Performance Indicators
Decrease in water penetration (BS 1881) ~ 83%
Tensile strength ~ 4.11 N/mm²
Solid content ~ 67% by volume
Recoating time ~4–6 hours
SANIFLEX‑Universal thus has an excellent opportunity as a roof waterproofing membrane behind tile or as a general-purpose protective coating in wet zones.
Application of SANIFLEX‑Universal Behind Tile Systems: Best Practice
To achieve best practice for optimum performance of SANIFLEX‑Universal behind tile, follow these guidelines:
Substrate preparation
Make the surface firm, clean, dust-free, oil-free, laitance-free, and free from defects.
Repair or fill voids, honeycombs, or cracks before application.
If the substrate is porous, pre-damp to SSD (surface dry) condition, in case excessive suction is avoided.
Priming (where necessary)
Some substrates can be improved by a primer to improve adhesion or prevent suction; consult product technical information.
Two or More Coats
Apply two or more coats of SANIFLEX‑Universal, each coat to dry adequately before the next is applied. (Recoat window ~4–6 hours)
Thickness / Coverage
Ensure that the total film thickness is sufficient for protection against water. Inadequate thickness may affect performance.
Reinforcement of Joints & Cracks
At joints in movement, at penetrations through pipes, at interior corners, or where there are transitions, install joint tapes or reinforcement (where required) before future coats.
Curing Time Before Tiling
Let the waterproofing membrane fully cure before tile adhesives can be used. Time will depend on coat thickness, temperature, and humidity; follow the manufacturer's directions.
Tile Adhesive Compatibility
Utilize flexible substrate-compatible tile adhesives or tiles that are specifically set to be installed over waterproof membranes. Avoid the use of bond-resistant adhesives or membrane-penetrating adhesives.
Tile Grout & Joint Sealants
Insert good grout and flexible sealants along perimeters, trims, and transitions to ensure the entire system is watertight.
FAQs
Q1: Is it acceptable to omit a roof waterproofing layer behind the tiles and just have tile + grout?
No. It should not be done single-handedly using grout and tiles. Grout is porous, will eventually crack, and is rarely ever sufficient under hydrostatic head or in wet areas. A membrane like SANIFLEX‑Universal offers a second line of defense, protecting the substrate and structural elements from water damage.
Q2: Can SANIFLEX‑Universal be used on interior bathrooms as well as exterior balconies or terraces?
Yes. SANIFLEX-Universal is applicable internally and externally, i.e., below or above screeds, flat roofs, balconies, pools, and concrete/masonry damp-proofing.
Conclusion
Waterproofing behind tile isn't an option for the DIYer—it's something required for durability, structural integrity, and management of water. Aquafin Pakistan's SANIFLEX‑Universal is a tough elastomeric coating that incorporates waterproofing and air permeability, adhesion and crack bridging, UV resistance, and functional application ease.
If you’re planning a balcony, wet room, or any moisture-prone surface, give your tiling system the protection it deserves. Contact Aquafin Pakistan’s technical team for project-specific guidance on using SANIFLEX‑Universal in your next roof waterproofing design.
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