Concrete sealer advice and information - NZ speciality concrete sealer

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Choose the right concrete sealer.

Concrete sealer can come in many “flavours” (please don’t taste them).  There is much confusion and misconception about different types of concrete sealer.

A Concrete Sealer is applied to perform a certain task or duty.  It may be that you want  concrete sealer to protect a decorative concrete surface, or enhance coloured concrete, or stop dusting, prevent chemical attack preserve heritage builds or the like.  It is important to match the purpose to a concrete sealer than will perform that duty.

In this article I will discuss clear concrete sealers.  We will classify coloured sealers as “concrete coatings”.  They still seal the concrete but we will confuse the matter.

So a non coloured concrete sealer can be classified in one of 3 categories

1) Fully penetrating sealer – these concrete sealers are also referred to as densifiers.  There are a number of variations of densifiers/Fully penetrating sealers, but their characteristic is that they work by chemical reaction with “free lime” inside the concrete matrix and do not leave a surface coating.  More on these later……

2) Semi-penetrating topical coating – these sealers are low solid content and are able to soak or wick into the surface pores of the concrete to create a strong bond.  You could also refer to them as self priming sealers.

3) Topical coatings – these sealers are typically higher solids, 2 component, reaction resin based sealers.

Fully penetrating concrete sealer – Densifier

If we take a look at the first category, a fully penetrating concrete sealer, we need to understand what it does and why we would use it, and where.  If we think about them as a product that looks like water, is generally clear or slight colour, and soaks into the concrete.  Once it enters the concrete through the pores, it finds and reacts with lime or un-reacted cement (cement is burnt lime).

The Densifying concrete sealer then forms a gel, that swells and blocks the pores of the concrete.  The result is a more solid concrete surface that is no longer porous.

Pros

  • Permanently fused inside the concrete, won’t wear, flake or peel. (some work better than others)
  • Can prevent moisture transfer because it blocks the pores.
  • Stops dusting – unsealed concrete will continue to produce dust
  • Increases the density and therefore the abrasion resistance of the concrete.
  • Makes little or no visible to the surface (invisible sealer)
  • Does not make a surface slippery

Cons

  • Will not improve the appearance of the surface
  • Will not hold anti-slip additives
  • The surface can still stain (the stain usually won’t penetrate)

What is it best suited for?

Densifying penetrating concrete sealer is perfect for all concrete floors and surfaces that do not require a glossy finish, such as warehouse floors, big box stores, factory floors that do dry processes, driveways and external concrete.

What do we use?

Creteshield 101 – is a Potasium Silicanate.  It is at the top of the performance list.  An advantage of Creteshield 101 is that it is hydrophobic, meaning it repels moisture.  Most densifiers are hydrophilic, meaning they microscopically absorb moisture (they will stop moisture transfer, but over a long period of time they dissolve).  Creteshield 101 will increase abrasion reistance by about 40%.  Also suitable for greatly reducing Radon Gas. Creteshield 101 is the best product to use as a stand alone densifier.

Creteshield LS – is a Lithium Silicate.  A true Nano particle densifier.  The lithium carrier/binder creates a non soluble permanent bond within the concrete matrix.  Creteshield SL is great for Diamond Polished Concrete (DPC) and floors treated with Creteshield SR PRO (a semi topical polish/stain resistor)

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