Sika Sikagard 720 EpoCem

Key features

• Epoxy-modified cementitious formulation — epoxy resin penetrates concrete pores for chemical bonding while the cement component undergoes hydration, providing a dual bonding mechanism
• Excellent adhesion to dry or damp concrete — can be applied directly to damp substrates (substrate must be moist but free of standing water)
• Impervious to liquids, permeable to water vapour — blocks liquid water while allowing the substrate to breathe
• Good thixotropy — suitable for vertical and overhead surfaces without sagging
• Three-component pre-dosed packaging — Part A (resin) + Part B (hardener) + Part C (powder), simple to mix
• Solvent-free — can be used in enclosed interior spaces, though adequate ventilation should still be maintained
• Fine surface finish — can serve as substrate preparation for subsequent epoxy systems or decorative finishes

Applications

• Negative-side waterproofing — basements, underground carparks, retaining walls, lift pits and other locations where exterior waterproofing is impossible; applied from the interior to resist external water pressure
• Pore sealing and levelling — filling pores and smoothing concrete and mortar surfaces
• Temporary moisture barrier — blocking rising damp from the substrate, preparing for subsequent floor coatings or finishes
• Chemically aggressive environments — protective rendering on concrete in sewage treatment plants, chemical facilities, etc.
• Epoxy system substrate — surface preparation mortar for subsequent Sika epoxy products

Why choose Sikagard 720 EpoCem

• Solves the "no exterior access" waterproofing problem — when basement or underground walls are surrounded by soil and cannot be excavated, 720 can be applied from the interior for negative-side waterproofing, offering an alternative to traditional chemical injection
• Dual bonding mechanism — epoxy chemical bonding + cement hydration crystallisation gives superior adhesion to damp concrete compared to single-system products
• Blocks water, allows breathing — impervious to liquid water but permeable to water vapour, preventing the coating from blistering under back-pressure

Application notes

Before application, clean the concrete substrate thoroughly (remove loose material, dust and oil), and dampen the surface to saturated surface-dry (SSD) condition — a bone-dry substrate will draw moisture from the mortar and impair the cement hydration needed for proper bonding. Mix the three components in the correct ratio: first blend Part A + Part B (liquids) thoroughly, then add Part C (powder) and mix with an electric stirrer until homogenous. Ideally use the full pre-dosed set in one batch; if splitting, weigh each component with a digital scale to maintain the correct ratio. After application, carry out proper curing — do not allow the coating to dry too quickly.

For coverage, layer thickness, curing times and primer requirements, refer to the product Technical Data Sheet (TDS).

What is the difference between 720 and 107?

Both belong to the Sika waterproofing system but address different water-pressure directions: SikaTop Seal 107 is for positive-side waterproofing (water pushes against the coated face, e.g. bathrooms, kitchens, water tanks), while 720 EpoCem is for negative-side situations (water penetrates from behind the substrate, resisted from the interior). Use 107 for bathroom waterproofing; use 720 for basement/underground waterproofing from the inside.

FAQ

Can Sikagard 720 be applied to damp concrete?
Yes. 720 has excellent adhesion to both dry and damp concrete. Before application, dampen the substrate to saturated surface-dry condition, but ensure there is no standing water.

Can 720 replace chemical injection (grouting)?
They work differently: chemical injection targets individual cracks with injected resin, while 720 provides a continuous coating over the concrete surface. Depending on the cause and site conditions, one or both methods may be used — the specific approach should be determined by relevant professionals.

Is 720 suitable for ceiling leaks?
720 is primarily for negative-side waterproofing (water penetrating from behind the substrate). If the source of a ceiling leak can be repaired from above (e.g. fixing waterproofing upstairs or sealing window ingress), it is better to address the source first. Negative-side treatment is a remedial option when the source cannot be reached.

Most products typically in stock. For detailed technical data and application conditions, refer to the product Technical Data Sheet (TDS), or WhatsApp Wah Hing.