Product Data Sheet Show all documents

SikaTop®-521 Seal

(former MSeal 521)

Polymer modified cementitious, durable, waterproof coating.

SikaTop®-521 Seal is a two-component, acrylic modified, cementitious coating that requires only on-site mixing to form the ideal product to provide a durable, waterproof coating to re-surface concrete, masonry, and most other construction materials. SikaTop®-521 Seal imparts the natural concrete appearance.

  • Excellent adhesion – bonds to porous and non-porous surfaces
  • Limited flexibility
  • Suitable for light pedestrian traffic
  • Breathable – whilst repelling water, allows substrate to breathe
  • Slurry or trowelable consistency; application is still possible by spray
  • Unlike conventional coatings, which require a 7-28 day cure of concrete,
Product Data Sheet Show all documents

Usage

  • To re-face and even out variations in concrete surfaces.
  • As a waterproof coating for water-retaining structures like water tanks, pools, etc.
  • To provide foundation protection As a backing to marble and granite to prevent water ingress, and thus alleviate surface staining.
  • To provide protection to concrete surfaces from carbonation and chloride attack.
  • For use on pedestrian walkways in marine areas.  

Advantages

  • Excellent adhesion – bonds to porous and non-porous surfaces
  • Limited flexibility
  • Suitable for light pedestrian traffic
  • Breathable – whilst repelling water, allows substrate to breathe
  • Slurry or trowelable consistency; application is still possible by spray
  • Unlike conventional coatings, which require a 7-28 day cure of concrete,

Packaging

Available in 20kg double pack (15kg powder+5kg liquid).

Colour

Available in light grey and white

Product Details

Product Information

Composition

SikaTop®-521 Seal is composed of specially selected cements, silica sand and reactive fillers supplied in powder form together with a liquid component of blended acrylic copolymers and wetting agents.

Shelf life

Up to 12 months if stored according to manufacturer’s instructions in unopened containers.

Storage conditions

Store out of direct sunlight, clear of the ground, on pallets protected from rainfall. Avoid excessive compaction

Density

Approx. 2000 kg/l

 

Application

Consumption

Consumption

0.75-0.9kg/m²/coat, depending on the substrate roughness. (Minimum 2 coats are required).
Application steps

SUBSTRATE PREPARATION

As with all coating systems, surface preparation is of prime importance. Remove all grease, oil, dust and residual curing compound, mould release agent or other contaminant that could impair adhesion.
Laitance should preferably be removed by light sweep blasting or hydro jetting. Mechanical wire brushing may be appropriate for small areas. Spalled concrete should be cut back to sound concrete and made good with a suitable cementitious repair mortar.

MIXING

SikaTop®-521 Seal is supplied in pre-measured units and should be mixed on site utilising clean containers. Slowly add the powder to the liquid and mix, using a slow speed drill fitted with a suitable paddle.
MIX AND USE. Do not mix more material than can be used in one hour.
NOTE: Although SikaTop®-521 Seal is supplied in pre-measured packs, part packs can be used by mixing 4.5 parts of powder to 1 part of liquid by weight; mix thoroughly and keep mixed during application.

 

APPLICATION

Do not apply to dry concrete. Saturate concrete surfaces with clean water whilst still visibly damp, but free of standing water. Apply, using a short, stiff bristle brush or roller. Trowel application can be undertaken as necessary. For heavy 6-10mm depressions, honeycombs, etc., use less gauging liquid and mix to the desired consistency. Where more than one coat is found necessary to achieve the desired thickness, apply the second or subsequent coats after the previous coat has dried.

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