How to Choose the Best Silicon Sealant?

The final phases of a building entail a lot of interior finishing, and some of these work involve wet areas that need water proofing, especially in the joinery to ensure that water does not penetrate.

Sealant Application

If the finishing on joinery, for instance, where a sink sits on a granite top is not done properly or the wrong silicon sealant is used, then you are likely to see some water go through the joints and find its way to the wooden cabinets below. This will inevitably lead to costly repairs as the water continually seeps in to the wood causing ugly stains and rot.

Silicon sealant applications are numerous during the building process. However, the most obvious ones are in the final phases of building construction.

It is common for building materials to expand and contract or experience slight movement in the course of the life of the building due to weather cycles. This fact makes it imperative to seal buildings from the tiniest of spaces in order to prevent unwanted insects, air and water from making their way into the building.

Proper sealing between any door or window frame and the building is crucial part of any installation.

Common Sealant Types

Other than silicon, there are many sealants to be found in the market and for various applications. These include;

  • Polyurethane
  • Mastic
  • Acrylic
  • Hybrid

Differences Between Sealants

As mentioned above, sealants are numerous, but it is their varying properties or the combination of these properties that determines what sealant is best for a given application.

Properties to be considered include;

  • Curing method – This is an important point of consideration. For instance, an acetic acid cure product would not be the best option for glass or metal elements for both doors and windows as it gives off compounds which are detrimental to such surfaces
  • Bonding – the adherence and bonding ability of a sealant product to various surfaces should be considered as the various surfaces need different bonding
  • Elasticity – the ability of the sealant to move and retain its properties is crucial
  • Resistance to UV rays – ability to withstand exposure to UV rays must be factored in because this is a leading cause of deterioration in sealant
  • Paintability- can they be painted over?

Types of silicon sealants

Generally speaking, you will find two types of silicone sealants and both are not paintable and they include:

  1. Acetic acid cure

Acetoxy cure silicon has some major draw backs which include: not being able to adhere well to most building materials, and is harmful to glass in windows and metal elements doors.

  1. Neutral cure

This would be the best silicone sealant option because it is fairly affordable and possibly the lowest in terms of cost, in comparison to the other types of sealants. And not only does it have the best UV resistance but it also has the longest lifespan.

Polyurethane sealant


Polyurethane is a non-silicone based option. Unfortunately, it does not weather well and has a very short lifespan in comparison to silicone. It is, however, paintable.



Manufactures have now come up with hybrids that comprise of a combination of modified silicon and polyurethane. This hybrid combines the best properties of these two to form a sealant that is UV resistant, with a long lifespan, good adherence and is paintable.

Polyurethane sealant

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