Supersilicon (Render Seal)

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Supersilicon (Render Seal)

Click to zoom

Supersilicon (Render Seal)

Click to zoom

Supersilicon (Render Seal)

Click to zoom

Supersilicon (Render Seal)
Supersilicon (Render Seal)
Supersilicon (Render Seal)
Supersilicon (Render Seal)

Supersilicon (Render Seal)  

122.41Inc. VAT102.01Ex. VAT Next Day Delivery Available

Supersilicon (Render Seal) is your easy solution to leaking or damp render. It also inhibits the growth of unsightly black, red & green moulds. Read More

Product Code:26ba20
Colour Palette:

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The Liquid "Render Mender"

Damp is always a nuisance, but damp render can seem like one of the more frustrating varieties to resolve.   Often the damp patch showing up on your bedroom or living room wall, doesn’t correspond to any obvious crack or damage to the render outside?  So where is the leak?  And why is the render covered in ugly mould staining?  The good news is that at Kingfisher we have seen this many times before, so before you reach for the mash hammer and bolster, please read on.

This latest version of Supersilicon has many outstanding features, including:  

  • Seals damp walls from further moisture penetration
  • 100% Breathable & Micro-porous
  • Completely invisible when cured
  • 5-year minimum life
  • Seals unpainted renders, masonry, and cement mortar joints
  • Suppresses salting (efflorescence treatment)
  • Immediate development of water repellence 
  • Improves energy efficiency by reducing evaporative heat loss
  • Suppresses mould and moss growth on renders and masonry
  • Also seals limestone without any surface darkening

How does it work?

Supersilicon creates an invisible barrier to rainwater, sleet, hail, and snow.  It soaks into the masonry or rendered surface where it cures to form a breathable barrier, that still allows any moisture within the substrate to escape.

The reasons a render might lose its waterproof characteristics are the same as for any other type of masonry.  The deterioration is often gradual over many years.  Tiny imperfections in the surface crack with repeated freeze/thaw expansion and contraction, which provides a path for water to enter the structure.   Or perhaps the original cement component was not s mixed up as strongly on one part of the wall, compared to others.  There are innumerable variations, but the resulting porous surface always results in all the same outcomes:  damp plaster, black mould, sometimes degraded air quality and even timber decay.

Of course, one product alone will not solve all penetrating damp issues, but Supersilicon provides builders, homeowners & damp proofing professionals with a significant defence against the problem.  It limits the absorption of water, which is the starting point for most decay.

It achieves this by embedding an invisible barrier, developed from siloxanes known for their hydrophobic (water repelling) characteristics. This then reduces capillary absorption within the microscopic channels in the render or masonry. There is therefore little or no impairment to the wall’s ability to ‘breathe’. 

Supersilicon can be used in many penetrating damp situations including:

  • Domestic properties
  • Commercial properties & warehousing
  • Industrial letting units
  • Rental properties
  • Terraced houses
  • Detached and Semi-detached properties

Indirectly it may also reduce condensation.   Leaking render or masonry can cause interstitial condensation because “a damp wall is a cold wall”.   Put simply, even if the wall is only partially absorbing water (say 150 mm into a 300mm wall) that “partial porosity” nevertheless exerts a significant chilling effect, especially in winter, because when moisture evaporates off, it carries heat with it.    This in turn causes condensation to form internally which is sometimes mistaken for structural damp.

Supersilicon restricts the ability of absorbent building materials (render, old bricks, soft mortar joints etc.) to soak up that moisture in the first place, with two effects:

a)  Evaporative heat loss (described above) is greatly reduced. b)  Condensation “cold spots” are eliminated from internal walls

How to use Supersilicon?

Brick walls, stonemasonry and rendered finishes should be thoroughly cleansed of all dirt, carbon deposits, green mould, moss, and other organic growth.   Where render is in good condition and there are no “hollow” sections, careful pressure washing with a fan nozzle (do not use “rotary jet” or “turbo” nozzles) will provide rapid removal of most contaminants.   If there is any evidence of organic matter, pre-treat the surface with a liberal application of Kingfisher Bio-Wash (HSE certified) to loosen any mould or moss accumulations.

Where the substrate is considered fragile, use Kingfisher Eco Brick Cleaner to remove carbon and salt staining.  Agitate with a scrubbing brush and repeat cleanse/rinse cycle two to three times if necessary.

Surface Sanitise
Often when organic matter is cleansed from an external wall it is apt to grow back again “with a vengeance”.  This seems counter-intuitive until you understand that cleaning may remove the moss growth for example, but it also spreads the invisible spores around too, which quickly re-establish, often to a wider area.  An application of Kingfisher Bio-Wash kills these spores and micro-root systems, so is considered an essential surface preparation before applying Supersilicon.


Damaged sections of render or mortar are a common source of moisture ingress, and no breathable water repellent on its own, will remediate such issues.  Cracked or hollow sections of render should be repaired, usually by a specialist who will have the skills to match colours and blend the repairs into their more weathered surroundings. Loose cement or lime mortar joints should be mechanically raked out to a depth of at least 20mm and new mortar pointed in to create a water-proof joint.  We recommend Kingfisher Pointing Mortar & Pointing Solution for best results.


a) Supersilicon is a ready-to-use formula and should be applied directly to the render, porous or stone.  Do not apply to engineering brick, dense stone (granite), polished stone or marble.  

b) 2 coats should be applied.  Apply to refusal by brush or low-pressure sprayer.

c)  We suggest starting at the top of the work area and working downwards, allowing runs and drips to be captured and spread by brush (even if main method of application is spray).   Work in the horizontal plane and avoid spraying overhead.

How much do i need?

The coverage rate is approximately  5 sq m per litre, so a 5 litre of Supersilicon should treat at least 12.5 sq m with the recommended two coats.


a) Do not apply to engineering brick, dense stone (granite), polished stone or marble.
b) Do not apply during precipitation
c)  Cover up if rain expected within 24 hours of application
d) Not for use indoors unless well ventilated during application and curing
e) Do not apply near any live sources of ignition (inert when cured) 

Technical Support

As always, we recommend that you read the Technical Data Sheet & Safety Data Sheet thoroughly before commencing any work.  If in doubt please call us for advice, we are here to help. contact us


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