About Sika Polysulphide, Pour Grade

Sika Polysulphide, Pour Grade is the horizontal-joint member of Sika’s two-pack polysulphide family, formulated with a pouring consistency so it can be poured directly into floor and pavement joints rather than gunned. On site it arrives as a base (Part A) and a curing agent (Part B); once these are blended in the fixed 92:8 ratio, the material cross-links into a solid yet flexible rubber that bonds tenaciously to primed concrete and stays watertight through years of thermal cycling and wheel loading. Because it self-levels, the finished seal sits flush with the slab with no tooling, which is exactly what a fast-moving flooring or road crew wants on long runs of joint.

For engineers and consultants, the appeal is the combination of movement capability and chemical resistance in one product. The cured sealant absorbs the expansion and contraction that concrete slabs undergo between summer and monsoon while shrugging off spilt fuels, oils and cleaning solvents that would degrade cheaper mastics. That makes it a dependable specification for warehouse floors, loading yards, service stations, tunnels and reservoirs, where a joint failure means water ingress, dusting edges or corrosion of the reinforcement below. As Sika’s authorised distributor and applicator, Space Arc Engineering supplies genuine stock with batch traceability and can advise on joint design, priming and pour sequencing for the specific slab in front of you.

The technical insight

Polysulphide chemistry is what gives this sealant its long service life. The base polymer carries reactive end groups that, on contact with the Part B curing agent, link together into a three-dimensional elastomeric network. That network behaves like a rubber band across the joint: as the slabs move apart or push together, the sealant stretches and recovers instead of tearing or debonding, which is why it clears the 30% extension and 30% compression test without cohesive or adhesive failure. The same sulphur-rich backbone is inherently resistant to hydrocarbons, so fuels and oils that swell or dissolve ordinary sealants have little effect. The pouring grade differs from the gun grade only in rheology; it is thin enough to flow and self-level under gravity, so on a horizontal joint it fills every corner and leaves a smooth surface without the striking or tooling a paste sealant needs. Correct joint geometry is essential to that performance: designing to a 2:1 width-to-depth ratio keeps the sealant thin enough to flex freely, and a bond breaker or backer rod at the base stops three-sided adhesion that would otherwise concentrate stress and split the seal.

Where it is used

• Sealing expansion and contraction joints in industrial and warehouse floors subject to forklift and truck traffic
• Movement joints in concrete pavements, roads, parking decks and hardstandings
• Joints in bridge decks, flyovers and elevated approach slabs
• Water-retaining and water-excluding structures such as reservoirs, dams, canals and water-treatment tanks
• Joints in subways, tunnels, culverts and underground service ducts
• Fuel-exposed areas including petrol-station forecourts, aircraft aprons and vehicle workshops
• Joints between dissimilar construction materials where differential movement is expected
• Runway and taxiway joints at airports requiring flexible, fuel-resistant sealing

Key advantages

• Pours and self-levels into horizontal joints, so long runs are sealed quickly with no tooling
• Accommodates around 30% extension and 30% compression without cohesive or adhesive failure
• Cures to a permanently elastic, watertight rubber that keeps water out of the structure
• Resists water, fuels, oils and many solvents, suiting fuel-exposed and industrial floors
• Tough enough to carry vehicular and forklift traffic once cured
• Withstands UV and weathering, retaining flexibility over a long service life
• Complies with recognised British, Indian and IRC joint-sealant standards for confident specification

Limitations & considerations

• Pouring grade is for horizontal joints only; vertical and overhead joints need the gun grade instead
• Requires priming of joint faces with Sika Primer-3 and a bond breaker or backer rod for reliable adhesion
• Application is limited to substrate and air temperatures between +5 degrees C and +45 degrees C
• Being two-component, it must be fully mixed at the fixed 92:8 ratio; part-batching or hand mixing risks patchy cure
• Reaches full properties only after 7 days, so heavy chemical or traffic exposure should wait until cure is complete
• Joints must be clean, dry and sound; oil, dust or laitance on the faces will compromise the bond

Selection & best practice

Specifications

Industry use cases

How we position Sika Polysulphide, Pour Grade

Within the Sika family, pair this pouring grade with Sika Polysulphide, Gun Grade for the vertical and overhead joints on the same project, and always specify Sika Primer-3 for the joint faces. Where the requirement shifts from a poured field sealant to a pre-formed, heavy-duty floor joint, Sika FloorJoint EX A and Sika FloorJoint XS are the natural step-up within the same brand. Across our other brands, contractors sealing lighter or faster-cure joints often ask about polyurethane alternatives, and for two-part polysulphide in particular the Fosroc equivalent is a well-known direct counterpart.

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