Selecting the appropriate sealant for a specific application is a complex and multifactorial process. The key parameters that determine the most suitable material include:

• The substrates type

• The joint’s size

• The joint’s mobility

• The temperature and humidity conditions during the application

• The temperature and humidity conditions throughout the sealant’s lifetime

• The sealant’s available shade

• The cost

• The UV radiation resistance requirement

• The water resistance requirement

• The aesthetic effect

• Resistance to fungi

• The sealant’s chemical resistance

• Compliance with current legislation or specifications, etc.

To simplify the complex process of selecting the right sealant, which requires significant experience and knowledge, it’s recommended to use sealants that cover a wide range of applications. These include neutral silicones (such as S-900 and Isofix Neutral) and silane-terminated polymers (such as Elastobond, Elastobrid, and Isofix Hybrid).

Alternatively, you can consult the application table for the Isofix range. It should also be noted that for most applications, you can use two or three different products with equivalent results.

S-Hi Temp is a silicone sealant that can functionally withstand temperatures up to 270°C and up to 300°C for short periods. It’s ideal for applications requiring high temperature resistance. Firescal W is a sealant that can withstand very high temperatures (up to 1200°C), but it lacks elasticity and water resistance.

Therefore, it’s suitable for use in internal joints without mobility, such as joints in fireplaces. Fire Acrylic is a special acrylic sealant that expands when exposed to fire, delaying the transmission of fire through the frame joint. It’s ideal for sealing joints around fire safety doors in fire compartments.

Suitable materials for joints in permanent immersion are S-900, Elastoseal and Elastotan. However, for swimming pools, due to the chlorine content, only S-900 (specifically, the transparent one)

is recommended. It’s particularly important to consider the application substrate, as porous substrates (such as concrete) require the use of special primers.

Acrylic sealants are suitable for external use in vertical joints. However, it’s recommended to avoid using them in horizontal external joints, especially in areas with stagnant water.

The main causes of detachment of acrylic sealants and the creation of a crack in the joint are as follows:

• Low elasticity of the acrylic sealant

• Moderate to poor adhesion to the substrate

• Shrinkage of the acrylic sealant mass due to water content

• Reduction of the sealant’s elasticity and hardening due to low temperature

• Large variation in joint width

To achieve optimal results, it’s recommended to use highly elastic acrylic sealants, such as Sealac or to use sealants superior to acrylics in elasticity, adhesion and shrinkage, such as silicone sealants (S-100, S-900), polyurethane sealants (Elastoseal-PU) or hybrid sealants (Elastobond, Elastobrid, Isofix Hybrid).

Acrylic sealants dry by evaporating the water they contain. The rate of evaporation is significantly affected by the temperature and humidity conditions of the environment.

Acrylic sealants dry by evaporating the water they contain. In conditions of low temperature and high humidity, water-based products fail to dry sufficiently and gain strength, even after several days of application. In these conditions, acrylic sealants are vulnerable to rain,

which can dissolve and wash them away.
To achieve optimal results, it’s recommended to use special acrylic sealants, such as Acrylic Pro 6000 or sealants that dry with the humidity of the ambient air (silicone, polyurethane, or hybrid sealants).

During summer, especially in areas exposed to the sun, acrylic sealants can form a surface film within seconds. This rapid film formation makes it difficult to apply the sealant evenly.

To achieve optimal results, it’s recommended to use Acrylic Pro 6000, which has a longer working time. Alternatively, you can apply the sealant with a suitable brush after wetting it in soapy water.

Silicones, in general, are ideal for external use as they exhibit excellent resistance to UV radiation (the highest known resistance among all elastomeric sealants), water, and temperature changes from -40°C to +120°C.

Silicones generally have long-term durability. However, the market is dominated by economical types of silicones, which present the following problems:

• Gradual shrinkage within the first 1-2 years after application, with shrinkage exceeding 25%-30%.

• Detachment due to weak adhesion to the substrate on which they have been applied (mainly applies to acid-acetic silicones).

For maximum strength and lifespan, use the following types: S-100, Super White 10, S-900, Isofix Neutral.

Acetoxy silicones are the most widely used type on the market. However, they have very limited adhesion to smooth substrates such as glass, ceramic tile, and stainless steel. They are also unsuitable for porous or synthetic substrates, as well as metals sensitive to oxidation.

In contrast, neutral silicones offer excellent adhesion to a wide variety of substrates, both porous and non-porous. This includes glass, tile, all types of metals, wood, concrete, marble, brick, PVC, polyacrylic, polyester, polycarbonate, and more. High-quality silicones contain silicone oil, which, when applied to highly absorbent surfaces like.

Acetoxy silicones may cause skin or eye irritation if there is direct contact while still fresh. However, once they have dried, which typically occurs within the first 24 hours, they become completely harmless to the human body.

In joints that experience frequent contact with water and limited exposure to sunlight, black spots (fungi) may develop over time. These spots can gradually spread, leading to the complete blackening of the silicone. To mitigate or delay fungal growth, fungicides are often incorporated into silicones.

However, in most cases, the growth of fungi is not entirely prevented due to the following reasons:

• Most inexpensive silicones contain lower quantities of fungicides than recommended or use less effective fungicides.

• Economical silicones often experience significant mass loss, which leads to a reduction in the fungicide they contain.

• Many fungicides degrade with frequent contact with water, diminishing their effectiveness over time.

• The presence of organic residues and soap in silicone promotes and inevitably leads to fungal growth.

For the best possible result, we recommend the Super White 10 silicone type with the ten-year warranty, combined with regular cleaning and rinsing of the joint with plenty of water to remove soap residue.

High-quality silicones contain silicone oil, which, when applied to highly absorbent surfaces like marble, can cause staining of the substrate near the joint.
To avoid this issue, especially in joints with porous marble

or natural stones and in applications where aesthetic considerations are crucial (such as ornamental marble in buildings), it’s recommended to use the specialized Elastotan-5 elastomeric sealant.

Silicones cure by reacting with the humidity in the ambient air, transforming from a fresh paste into a rubbery substance. Drying initially occurs at the surface in contact with the air and then gradually progresses inward. The rate of drying depends on the temperature and humidity of the environment, as well as the thickness of the silicone layer.

As a general guideline, at a temperature of 20-25°C, a surface film typically forms within 15-25 minutes, while curing within the mass progresses at a rate of 2-3 mm during the first 24 hours. One-component sealants, such as silicone, should not be applied in thicknesses greater than 2 cm, as curing within thicker layers is significantly delayed.

Silicone is primarily a sealant, but it also possesses sufficient mechanical strength (with tensile strength around 2 N/mm22) to be used as an adhesive. Special grades of silicone, such as S-100, S-900, IG-1k, and

SG-1k are recommended for adhesive applications, provided that the silicone is applied in a manner which allows it to cure properly by ensuring adequate air exposure.

Mounting adhesives are high-viscosity (thick) and thixotropic (self-supporting, non-flowing) adhesives used for a wide range of applications, including mounting, hanging, and suspending objects, as well as replacing screws, plugs, or nails.
Their main advantages over nails or screws are that they don’t require drilling into the object or substrate and they distribute the load across the entire contact surface,

The products listed are all mounting adhesives with distinct characteristics:

Montage Stick:
A mounting adhesive that dries by evaporating the water it contains.

• Low cost
• Suitable for sensitive substrates, such as expanded polystyrene (styrofoam)

• Difficult to dry between non-porous substrates; at least one of the surfaces should be porous
• Moderate adhesion on fairly smooth substrates

Montage S:
A mounting adhesive that dries through the evaporation of solvents it contains.

• Suitable for both porous and non-porous substrates

• Not suitable for solvent-sensitive substrates, such as Styrofoams

Lastostick:
A polyurethane adhesive that cures with the humidity of the air or substrate.

• Suitable for both porous and non-porous substrates
• Bonds even to wet surfaces
• Fast curing
• Moisture on the substrate accelerates the curing process

• May exhibit some mild swelling during drying, which is generally undesirable

Elastobond:
A moisture-curing adhesive based on silane-terminated polymers.

• Suitable for both porous and non-porous substrates
• Bonds even to wet surfaces
• Moisture on the substrate accelerates the curing process
• Doesn’t swell during drying
• Elastic

Elastobond Hi Tack:
This is a modified version of Elastobond with particularly high viscosity (thick consistency).

• The high viscosity allows it to support heavy objects without the need for temporary support (such as double-sided tape), until the adhesive fully cures.
• The adhesive’s high viscosity creates a “suction cup” effect, enabling it to hold loads effectively even when fresh.

• Due to its high viscosity, it requires a special heavy-duty silicone gun for application and cannot be used with thin cartridges.
• The category of adhesives based on silane-modified resins (such as Elastobond and Elastobond Hi Tack) represents the latest technology. These adhesives are increasingly preferred over traditional water-based, solvent-based or polyurethane adhesives due to their superior performance.

Elastomeric sealants and adhesives are classified based on the hardness of the elastic mass after complete curing, as measured by the SHORE A scale, which typically ranges from 15 to 60. A lower hardness index indicates a softer sealant, while a higher index indicates a harder one. Softer elastomeric sealants, in the 15-30 range, are more suitable for sealing high-mobility joints, such as concrete expansion joints.

SMPs, or Silane-Modified Polymers, are typically silane-terminated polyols or polyurethanes. The term “MS polymer” is a trade name for these polymers developed and patented by the Japanese company KANEKA, which pioneered the first silane-terminated polymer. SMPs represent a new class of polymeric resins commonly used in sealants and adhesives.

SMPs combine the key benefits of silicone and polyurethane resins, while also offering additional unique properties. The main advantages of SMPs are as follows:

• Excellent adhesion to almost all substrates
• Ability to adhere to wet surfaces
• Resistance to yellowing

• No formation of bubbles during curing
• Compatible with standard wall or industrial paints
• Capable of developing very high mechanical properties
• Particularly suitable for bonding applications
• Free from solvents and isocyanates (commonly found in polyurethanes), which are considered harmful to users, etc.

Translucent SMPs generally exhibit reduced performance compared to colored SMPs. To achieve transparency, certain key components that enhance sealant properties are omitted from ultra-transparent SMPs.
Specifically, translucent SMPs tend to be less effective than colored SMPs in the following areas:

• Adhesion
• Mechanical properties

• Elasticity
• Color stability

Additionally, translucent materials lack the pigments and fillers used in colored SMPs, which act as UV filters. As a result, translucent SMPs are significantly less resistant to sunlight compared to their colored counterparts.

Certification for 25 years, based on the European directive ETAG 005, indicates that waterproofing products for roofs have been tested and certified for a projected lifespan of up to 25 years (Category W3). This certification provides an expected lifetime for the sealant product and details the method and thickness of the sealant application.

Roof waterproofing can be achieved using either liquid applied waterproofing kits or membranes (such as asphalt, PVC, etc.). The main advantage of liquid applied waterproofing kits is their ability to form a 100% bond with the substrate. This means that if a localized failure occurs, water leakage is confined to the affected area, making it easier to address the problem with a simple, localized repair.

In contrast, if there’s a failure in membrane systems, it’s often challenging to locate the precise leak point and repair it effectively. This usually necessitates the complete removal of the membranes and application of new waterproofing, which can be more costly and disruptive. Additionally, liquid applied waterproofing systems don’t require specialized crews for application, unlike membranes, which must be installed by trained professionals, further increasing the cost of application.

Liquid applied waterproofing materials are categorized into three main types:

1. Water-based products (e.g., acrylics, acrylic-polyurethane hybrids, two-component cements)
2. Products that cure with atmospheric humidity (e.g., polyurethanes, silanes)
3. Two-component products with 100% solids (e.g., polyurethanes, polyureas)

Lastoflex products primarily fall into the category of coatings that cure with atmospheric humidity. The main advantages of these systems include exceptional water resistance, since they offer very high resistance to water (including ponding), and outstanding low-temperature performance, which means they remain effective even at temperatures as low as -40ºC.

They also possess excellent mechanical properties and provide superior adhesion to common substrates. Additionally, they can be applied and cure effectively even under low-temperature conditions.

Due to these properties, coatings that cure with atmospheric humidity are suitable for permanent waterproofing applications, with an expected lifespan that can exceed 25 years based on certification.

In contrast, water-based coatings generally have limited resistance to water, particularly ponding as well as limited resistance to low temperatures. These two major disadvantages often lead to potential peeling or cracking of the coating. They also cannot be applied in winter weather, as low temperatures and high humidity hinder the evaporation of water and impede curing. Typically, their durability doesn’t exceed 2–3 years, requiring reapplication.

Two-component products with 100% solids are less commonly used due to their more complex application process and higher cost compared to single-component coatings. However, their main advantage is their rapid drying time, even at large thicknesses, making them suitable for specialized applications.

The Lastoflex range is extensive and covers a wide variety of applications. The products can be divided into two main categories:

1. Suitable for Exposure to UV Radiation: Lastoflex-PU, Lastoflex-ST, Lastoflex-MS, Lastoflex-AT, Lastoflex-AR, Lastoflex-TR, Lastoflex-W
2. Unsuitable for Direct Exposure to UV Radiation: Lastoflex-PB 1k, Lastoflex-PB 2k, Lastoflex-TC

The main characteristics of products suitable for exposure to solar radiation are as follows:

Lastoflex-PU: Offers high mechanical strength and a competitive cost. However, it may experience slight discoloration and chalking over time.

Lastoflex-MS: Provides particularly high resistance to solar radiation, maintains its white color, and adheres directly to wet substrates.

Lastoflex-ST: Delivers maximum resistance to solar radiation and exceptional hydrophobicity.

Lastoflex-AT: Acts as a protective top layer over Lastoflex-PU, offering color stability and resolving chalking issues.

Lastoflex-AR: Also a protective top layer over Lastoflex-PU, similar to Lastoflex-AT but better suited for applications with higher pedestrian traffic requirements.

Lastoflex-TR: A transparent coating ideal for applications where preserving the appearance of the substrate is important (mainly used over tiles).

Lastoflex-W: An easy-to-use, water-based waterproofing solution with limited resistance to water and low temperatures.

In essence, Lastoflex-PU is a cost-effective option with long-term durability. For maximum performance, it’s recommended to use Lastoflex-ST, Lastoflex-MS, or Lastoflex-PU with an additional coating of Lastoflex-AT or Lastoflex-AR.

The main characteristics of products not suitable for exposure to the sun are as follows:

-Lastoflex-PB 1k: Very cost-effective and easy to apply.

-Lastoflex-PB 2k: Excellent elasticity and suitable for fast drying in large thicknesses.

-Lastoflex-TC: Ideal for use in enclosed spaces (solvent-free), quick-drying, and suitable for contact with drinking water.

Based on the above, Lastoflex-PB 1k is a general-purpose coating that’s particularly cost-effective and durable.

Priming is not always necessary and depends mainly on the type of substrate. Primers are used:

1. To improve the adhesion of the coating to the substrate.
2. To strengthen the surface of loose and porous substrates.

In many cases, Lastoflex coatings will bond directly to the substrate, making a primer unnecessary. Furthermore, there are situations where the primer might be unsuitable for a given substrate, leading to adhesion failure of the primer and consequently of the whole system.

Most primers are suitable for porous substrates (such as concrete) and are often unsuitable for non-porous surfaces, such as pre-existing waterproofing materials for example.

In general, ensure the compatibility of the primer with the substrate. Lastoflex should be used with the recommended primers from Elastotet. Consult the technical brochures for detailed application instructions. Mixing Lastoflex with primers from other manufacturers may lead to failures.

Lastoflex products are ready to use and don’t require dilution. However, if you need to reduce the viscosity to facilitate application with a roller or for use with airless spraying, you should use the solvents recommended by the manufacturer for each Lastoflex product.

Diluting the coating for the first coat is a technique sometimes used as an alternative to priming. This approach can help the diluted product penetrate better into porous substrates, potentially improving adhesion. However, Elastotet recommends using the designated primers—Primer VL, Primer Epoxy W, and Primer W40—as the preferred solution, rather than relying on diluted Lastoflex.

A common mistake that applicators of liquid applied waterproofing coatings make is to treat them like paints, calculating consumption based on coverage. They often assume that the applied amount, which visually covers the substrate, is sufficient to seal a surface. This may be true for paints, but not for waterproofing coatings.

For waterproofing coatings, the consumption primarily depends on the absorbency, roughness, and irregularity of the substrate. The recommended thickness of the dried film should be at least 1 mm. This is necessary to allow the coating to accommodate the contractions and expansions of the substrate in the daily and annual cycle and to bridge the micro-cracks that may be created.

In cases where substrates may undergo significant cracking (e.g., cement screeds, foam concrete), the dry film thickness of the coating should be doubled, and appropriate reinforcement (such as geotextile) should be used.

Assuming an acceptable dried film thickness of 1 mm, to calculate the consumption in kilograms, we need to know the density (specific weight) of the liquid coating as well as the percentage of solids.

If we apply a waterproofing material with 100% solids and a density of 1 Kg/lt on a smooth surface, then to achieve a dried film thickness of 1 mm, we would have a consumption of 1 Kg/m². In reality, however, most coatings have a density of 1.25 Kg/lt to 1.45 kg/lt and a volume loss (due to solvent or water content) of 15% to 30%. Additionally, the substrate is rarely perfectly smooth, leading to an increased consumption of 10% – 15%.

Therefore, the consumption to achieve a dried thickness of 1 mm ranges from 1.2-1.5 lt/m² or 1.5-2.0 Kg/m². When comparing different coatings, it’s crucial to make careful calculations, as some products are priced by volume (liters) and others by weight (kilograms).

Diluting the coating with — solvent or water increases the volume of the liquid, allowing you to cover more area per application. However, overall consumption remains unchanged. This is because the thinner evaporates during drying, leaving the same dried film thickness as the undiluted coating. Therefore, diluting the coating to increase the yield (cover more area) doesn’t make sense.

Polyurethane foams are classified according to the DIN 4102 specification based on their fire behavior. The categories are as follows:

• B1: Particularly slow burning
• B2: Slow burning
• B3: Normal flammability

Most foams (99%) fall into the B3 category. B1 and B2 foams are typically used around fire door frames.

Using a foam gun offers several advantages over hand foam:

• Increased yield: Gun foam produces significantly more liters than hand foam.
• Gradual use: A single bottle of gun foam can be used gradually over several days or even weeks. Unlike hand foam, which must be used immediately, gun foam doesn’t become unusable if left unused for a few hours, as the valve is less likely to block.