Here at Calfeutrage Apex, we are often asked why silicon-based caulking is our preferred choice of sealant and why it is better than other sealants.
Although we use silicone caulks ( You can read about Adseal series 4580) on most of our caulking projects, we use other scellant types when their characteristics are required for specific jobs.
A building’s location is significant when it comes to choosing the right type of sealant for a caulking project. During temperature changes, buildings extract and contract and therefore, buildings located in colder or hotter parts of the world, should be sealed with materials that can withstand these extreme temperatures.
In Quebec, we always prefer to caulk structures with flexible and durable sealants that can endure extreme freezing temperatures, as well as hot and wet summers without deteriorating prematurely.
Silicone sealants maintain their flexibility throughout a wide range of temperatures from as low as -40 degrees C to +232 degrees C. This flexibility and ability to extract and contract together with building components is what prevents these sealants from cracking or melting under the sun or breaking in freezing weather.
Silicone sealants are waterproof and water repellant. They repel water off their surface.
Silicone caulk can be applied to a wide variety of surfaces such as: ceramic, glass, metal, tubs and tiles. However, it can not be applied to wood.
- Cure time
Silicone caulking cures faster than other sealant types, typically, within 24-48 hours.
Silicone caulks and sealants are usually easy to clean by simply rubbing them off with the help of water/alcohol soaked rugs.
- Colour variation
Despite the fact that silicone caulks are typically not paintable, these sealants usually have an immense selection of colour variations to choose from.
- Removal process
Silicone sealants are mostly easy to remove from doors, windows etc…, so when the time comes to replace silicone joints, the price for the work should be lower than removing some other types of caulking.
Silicone sealants are mostly easier to apply due to their elasticity and consistency.
- Life span: 10-20 years
- Weak points
- All a while silicone caulk may have a flawless finish, impeccable results are reserved when applied by caulking professionals.
- Silicone based sealants are higher priced than regular residential sealants.
- Adhesion to wood and certain plastics form a weaker bond than some other types of caulking, which can be easily fixed with the use of a primer to strengthen said bond.
Let’s compare the Pros & Cons of Silicon-based caulking to that of other types of sealants.
SILICONE VS POLYURETHANE:
The main difference between silicone and Polyurethane based caulks is at the chemical level. Polyurethane is an organic material while Silicone is an inorganic material.
“The main properties of Polyurethane sealants are: strong adhesion, durability and strength. However, when exposed to sunlight and the presence of UV rays, polyurethane deteriorates and tends to lose its properties over time, unlike silicone, an inorganic material that has a high resistance to UV rays.
Polyurethane caulk tends to degrade at accelerated rates when exposed to sunlight as its UV resistance is low. It also has a tendency to crack and split when exposed to sunlight.
Polyurethane doesn’t withstand cold and heat cycles, while Silicone conserve its flexibility at temperature changes .
Polyurethane has better adhesion to specific surfaces like wood and some types of 3 part polyurethanes (colour pack, polymer-urethane base and a harder) can even stick to somewhat semi-humid masonry.
Polyurethane is unable to stick to the glass properly.
- Cure time
The time required to cure is typically longer than silicone, allowing more time for foreign contaminates to come in contact with the polyurethane caulking.
Cleaning the joints is difficult and almost impossible. Unlike silicone, polyurethane doesn’t wash easily.
Polyurethane sealants are prone to attracting dust and dirt all over their surfaces.
Polyurethane caulk has a tendency to facilitate the growth of moss and lichen in humid and shaded areas.
Colour variations are available, however, the selection is quite limited.
Polyurethane caulks tend to change colour over time: White can become yellow, dark colours fade and become a blue-grey shade.
The removal process of polyurethane from building components is harder than that of silicone. It requires more time and often may increase the price of a caulking service.
The consistency of polyurethane caulking is fairly liquid, meaning it is more likely to drip all over unwanted surfaces.
They also change consistency quite a lot when applied at different temperatures making the temperature at which they can be applied much more limited.
The application of polyurethane is challenging under cold or hot temperatures.
- Life span
The life span of most polyurethane caulking will be 10-20 years if well applied , however, polyurethane caulks can show signs of aging after 2-3 years on the south facing side of a building.
- WEAK POINTS
- Polyurethane caulk is a more toxic product, especially the types that contain Xylene.
SILICONE VS RUBBERIZED THERMOPLASTIC (AKA THERMOPLASTIC ELASTOMERS)
In the residential sector, the most commonly used type of caulking is rubberized thermoplastic.
Their main attraction is their very low cost when compared to commercial type sealants.
They are also available as a single unit meaning the buyer isn’t stuck with leftover material from a bulk purchase.
They are easily available to anyone at any hardware store in many colours.
Rubberized thermoplastic sealants are flexible & elastic and like silicone, they can stretch and shrink back to their original shape multiple times during temperature change.
On the downside, Thermoplastic Elastomers are caulking materials that repeatedly soften or even melt when heated and harden when exposed to freezing weather. Dark thermoplastics shades are tough to apply in the summer, leaving bubbles to expand within the caulk bead.
Thermoplastics degrade, lose their flexibility and crack when exposed to direct sunlight or ultraviolet light levels for extended times.
Thermoplastics have lower adhesion when compared to most sealant types.
They aren’t certified to be applied on glass, meaning they shouldn’t be used to replace thermo joints on windows.
Thermoplastic sealants change color quite fast: white will become yellow and black will fade, turning into a blueish gray color.
This caulk base has several colour variations.
Darker Thermoplastic colours become nearly impossible to remove under sunlight in the heat of summer.
Thermoplastics are soluble in specific solvents and will disintegrate when in contact with many solvents. They have a low chemical and heat resistance, high compression set and low thermal stability.
They cannot be tooled with wet wood tooling sticks meaning that all the lumps and imperfections are permanent and will remain present throughout the joint’s life expectancy.
Due to their tendency to thin out and become concave over time, their manufacturers recommend applying a convex bead of caulking to compensate for this effect.
- Life span
The fact that they degrade at a fast rate under UV rays, aren’t good after multiple heat-cold cycles and have fairly short life expectancy due to our Quebec climate, choosing thermoplastics makes it a poor choice.
ACRYLIC BASED CAULKING VS SILICONE.
Acrylic-based caulks are very resistant to ultraviolet light, and even if they soften under extreme heat, they will not melt, contrary to rubberized thermoplastics.
Acrylic sealants have very low flexibility, specifically during cold weather. They have a tendency to become extremely stiff under the brutal Canadian winters and eventually will fail.
Acrylic-based sealants provide a powerful bond with many types of materials, including most wood types.
Acrylic sealant types are also prone to staining, colour change and are difficult to clean.
Acrylic-based sealants are paintable, making the colour choice availability irrelevant should your shade not be available.
- Life span
5 years or less. It is among the caulking types most likely to crack, with low durability and resistance to the weather elements.
Its extremely strong bond factor makes it by far the most difficult of any caulkings to remove. On certain rough surfaces such as irregular stonework or none smooth surface bricks, it becomes impossible to remove the old acrylic caulking, meaning that the new caulking joint will need to be larger to cover the previous signs of acrylic residue.
The extra work and time required to remove acrylic caulking will make its replacement much more expensive than any other types of caulking.
Like silicone caulking applications in general, the application is fairly simple.
Acrylic type sealants don’t provide a professional finish look.