Two-part seal

Sahand Shimi’s two-component waterproofing is used to seal the floors and walls of all types of toilets and bathrooms, water tanks, concrete ceilings and slabs, roofs and roof gardens, pools, water features, treatment plants, and other tanks under positive hydrostatic water pressure.

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The most important feature of this cement-based product is its flexibility, high adhesion, and ability to create a complete seal with a very small thickness. Sahand Shimi’s two-component sealant has a technical certificate from the Research Center of the Ministry of Roads, Housing, and Urban Development.

This product can be applied to all vertical and horizontal concrete, cement, stone, and metal surfaces of floors and walls, and each pack of it allows for the sealing of 10 to 15 square meters of surface. One of the notable points of the two-component cement-based sealant is the possibility of tiling directly on it using appropriate tile adhesive.

Comparison of two-component waterproofing with insulation and bitumen

For many years, using insulation and bitumen has been a common method for sealing various surfaces. Two-component waterproofing is called a modern alternative to insulation. The two have fundamental differences in nature and implementation, some of which we will mention below:

Possibility of direct tiling

It is not possible to tile directly on insulation. Typically, for this purpose, rabbeting is done on insulation and mortar is applied. This method is time-consuming, increases the weight of the structure, and is generally associated with damage to the insulation.

In another method, insulation is done first and then walling and tiling is done on it, which may make the interior space slightly smaller. In contrast, tiling on two-component waterproofing is done directly using appropriate tile adhesive and does not require additional walling.
Comparison in terms of adhesion

Isogam is designed to adhere to horizontal surfaces and does not have sufficient and reliable adhesion on vertical surfaces. On vertical surfaces, Isogam may separate over time or not be able to withstand well unless it is stabilized with special adhesives. For this reason, it is better to use two-component sealants for insulating vertical surfaces, which have greater adhesion on these surfaces and provide better durability.

Due to its polymer component, the two-component sealant creates a strong connection with the underlying surface that is not affected by stresses and temperature fluctuations, and in this regard has a significant advantage over Isogam.

Comparison in terms of lifespan

The lifespan of Isogam is relatively short. This is while the two-component sealant is a cement-based product and, due to its cement component, if used as an intermediate layer, it will have a lifespan equal to the life of the structure.

Comparison in terms of environmental compatibility

There is a lot of pollution and dirt caused by soot and bitumen during the preparation and application of waterproofing and bitumen, especially in interior spaces and renovation projects. In contrast, the preparation and application of two-component sealant is much cleaner than waterproofing and bitumen, without additional pollution, without the need for heat, and without creating an unpleasant odor.

Applications of two-component sealant

It is possible to use two-component sealant in all places where waterproofing can be applied:

Floor and walls of recreational, agricultural, and industrial pools
Floor and walls of bathrooms and toilets
Types of roofs, terraces, and roof gardens
Types of facade walls and side walls of western rain gutters
Types of ponds and fountains

Sahand Shimi’s two-component sealant has a high speed of preparation and application, saving a lot of money and time.

Resistance of two-component sealant to building stresses

The polymer component based on acrylic resin in the two-component sealant, in addition to the high adhesive strength that it provides for bonding to concrete or cement surfaces, will make this two-component cement-based compound flexible.

Due to this feature, the created sealant layer with the ability to bridge cracks shows extraordinary tolerance against breakage caused by structural stresses and building settlements.

Application temperature of two-component sealant

This product can be used in the temperature range of -20 to +70 degrees Celsius. The results of the tests of the Research Center of the Ministry of Roads, Housing and Urban Development in this temperature range are available from the downloads section.

Two-component sealant as a final layer

It is possible to use Sahand Shimi’s two-component sealant as a final layer for cases such as ponds, water features or agricultural ponds that are less likely to be hit and damaged.

However, due to the physical conditions and low thickness of this product, it is relatively vulnerable and is not recommended as a final layer. Therefore, applying a protective layer such as a combination of cement and concrete or tile adhesive on it will increase the life of the seal several times.

Use in negative pressure environments

Sahand Shimi two-component seal is designed for use in positive hydrostatic pressures and is not effective for places with negative pressure.

Suitable surface materials for sealing

The best surface for sealing using Sahand Shimi two-component seal is a concrete or cement surface. These surfaces are most compatible with cement-based sealers. The possibility of applying this product on different surfaces is listed in the table below:

Plaster Wall Sealing Using Two-Component Sealant

Gypsum surfaces are unsuitable and weak substrates for the application of two-component sealant due to their very low strength and high moisture absorption. These surfaces have high moisture absorption, which leads to the simultaneous lifting (flaking) and release of the plaster and sealant from the surface.

If it is necessary to seal a plaster wall, the use of Sahand Shimi Construction Primer on the surface before sealing is mandatory.

Sealing a tiled pool

In terms of adhesion, the two-component sealant can be easily applied to tiles and ceramics. However, since this product is a cement-based and opaque mortar, the old tiles are not visible after sealing and there is a need to re-tile over the sealant layer with a suitable tile adhesive.

In such cases, a more systematic method is to destroy the tiles and prepare the concrete surface before sealing. If it is not possible to destroy the old tiles and to achieve better results, it is recommended to grind or chisel the surface using a milling cutter.

Using the two-component sealant on the facade of the building

Since Sahand Shimi’s two-component sealant creates an opaque and cementitious coating, using it as the final layer on the facade will cover the appearance of the facade. Therefore, it is recommended to seal with a two-component sealant before implementing the facade and then to apply the facade of the building with an appropriate method so that the final facade is maintained in the desired form.

To prevent water penetration from the facade of the building, it is necessary to cover the surface of the back wall with a two-component sealant before installing the facade stones and then proceed with installing the facade stones.

Otherwise, by applying Sahand Shimi’s facade hydrophobic product to water-absorbing surfaces, moisture absorption into the building can be partially prevented.

Calculating the amount of two-component sealant required

The volume of two-component sealant used depends greatly on how it is applied. Typically, each Sahand Shimi two-component sealant pack includes a 20-kilogram bag of cement-based powder and a 10-liter gallon of polymer resin, covering an area of ​​10 to 15 square meters.

To calculate the amount of two-component sealant you need, you can use the calculator on this page or the calculator page.

How to prepare a two-component sealant

Mix each 20 kg bag of Sahand Shimi two-component sealant powder with 10 liters of resin using an electric mixer. (2 to 1 weight ratio)

To do this, first pour the resin into a container with an appropriate capacity and slowly add the powder to the resin while stirring and continue mixing until a uniform and homogeneous mortar is achieved.

Give the mortar a rest for 5 minutes and then mix again a little. Now the sealant is ready to use. It should be noted that water or other substances should not be added to the sealant mixture.

Surface conditions under the work

Preparing the surface for sealing is a very important step that determines the final quality of the work. For this, first, cracks must be opened to the required depth using a milling cutter and weak spots must be destroyed. Then the surface is cleaned of any dirt, dust, paint and grease.

Using primer and repair mortar

After cleaning the surface, it is time to apply Sahand Chimi construction primer to increase adhesion and reduce water absorption of the surface, and then fill the surface defects with a suitable repair mortar. Using a primer significantly increases the adhesion of the surface and prevents the surface from absorbing water in the two-component sealant.

This will have a significant impact on increasing the quality and lifespan of the sealant. The primer is applied to the surface in a thin layer with a brush or roller, and after drying for a while, it will be ready to apply the repair mortar.

How to apply the two-component sealant

Use a clean container to mix the product. First, the liquid component is poured into the container and while the mixer is stirring the liquid part, slowly add the powder component and continue mixing until a homogeneous and uniform mortar is obtained.

This product can be easily applied by brush, roller, trowel and spatula. To perform the sealing, first apply the first layer in one direction (horizontal or vertical) on the surface and place the sealing mesh on it. The thickness of the first layer should be such that the mesh is well covered by the seal.

After 2 to 24 hours (depending on the air temperature), the second layer is applied in a direction perpendicular to the first layer. Note that the total thickness of both layers including the sealing mesh should not exceed 3 mm, as there is a possibility of cracking the seal at greater thicknesses.

Use of sealing mesh

Corners, pipe outlets and inlets, structural connection points in prefabricated walls and points with the possibility of cracking should be reinforced with sealing mesh. At these points, the possibility of cracking will be high due to increased stress.

Application temperature and workability time

The best application temperature for Sahand Shimi two-component sealant is between 5 and 40 degrees Celsius. At lower temperatures, the drying time of the sealant will be longer.

The period of use of the two-component sealant after mixing with resin (workability time) depends on various factors such as ambient temperature and the volume of the prepared sealant mortar. In general, to achieve the best performance of the two-component sealant, it is recommended to prepare only the quantities required for sealing for a maximum of 1 hour and then proceed to make a new sealant.

Paintability

Sahand Shimi two-component sealant is dark gray in color and can also be ordered in light gray. Water-based acrylic paints can also be used to apply color to the two-component sealant.

Setting time

The initial setting time of Sahand Shimi two-component sealant is between 2 and 24 hours (depending on the air temperature) and is ready for the water absorption test after 7 days. This time depends greatly on various factors such as temperature, humidity, sealant thickness and application conditions and may be less or more.

Expiration date and storage conditions

Sahand Shimi two-component sealant can be used for up to one year if stored in its packaging and in a dry place away from direct sunlight and moisture.

Note: In environments with acidic pH, it is recommended that the two-component sealant not come into direct contact with the acid. For this purpose, a suitable coating that adheres well to the two-component sealant can be used, or tiles can be installed to prevent direct contact of the two-component sealant with the acid.

Since the two-component sealant is a cement and resin-based product, it can change the factors of drinking water, so if used in drinking water tanks, it is recommended to use a suitable coating that has the necessary adhesion to the two-component sealant, or if a suitable coating is not used, be sure to perform water purification to adjust the amount of ions in the drinking water according to the standard.