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Expansion joint repair and sealing

We seal and repair expansion joints in poorly maintained concrete floors and offer a better solution with BECOSAN® polished concrete.


We perform repairs and sealing of expansion joints on concrete floors. This is a precursor to a treatment with our patented BECOSAN® system, where we harden and seal the concrete floor to minimise future damage.


Expansion joints in a concrete floor are a principal cause of deterioration of a concrete floor. It is important to repair these joints as soon as damage is detected to prevent further deterioration and disruption.

We recommend sealing these expansion joints immediately after a concrete floor has been laid, although we recognise this is not always the case. Through intensive use the edges of the joint begin to wear and can become a safety hazard for workers.

Timely repair of expansion joints will extend the life of your concrete floor.

Contact us for more information.
sellado juntas-min
arreglo de fisura hormigon


Expansion joints, or also known as isolation joints, have as their main function to absorb possible contact or friction due to movement between two construction elements.

Junta de Dilatación en pavimento

In addition, there are other types of joints such as contraction joints and construction joints.

In relation to industrial flooring, they are known as expansion joints because they regulate compression deformations in the concrete. These are caused by internal expansions, caused by thermal variations, load fluctuations, or movements of the concrete mass.

These isolation joints are designed to avoid the structural alteration of the reinforced concrete elements.

In addition, isolation joints provide mutual insulation between the concrete elements.

Concrete and reinforcing steel have similar coefficients of thermal expansion. They are exposed to thermal variations and both steel and concrete react collectively. The impacts of these variations are absorbed by the expansion joints.

Expansion joints can be classified according to their opening:

Open joints

These are unsealed joints, which makes them especially susceptible to the accumulation of particles and dirt, deteriorating rapidly if they are not maintained periodically.

These joints result from the determined calculation of the expansive movements of the material constitution between structural elements.

Sealed joints

Sealed joints represent the opposite of open joints. They maintain a separation between structural elements, which is sealed with an elastic and waterproof component. They are very resistant to humidity, temperature variations and erosion.     

Juntas de dilatación selladas


The main function of expansion joints is to prevent a cracking of the joints between two different slabs. This ensures that vehicle traffic can circulate on an even, safe and unobstructed surface.

Expansion joints are the least problematic type of joint in a concrete construction, compared to contraction joints or construction joints.

Contration joints and construction joints face the stress alterations that occur in the volume of concrete, which lead to the formation of cracks and fissures. This scenario is the most frequent, unlike the expansion joint scenario.

Technical reasons for expansion joints

The physicochemistry behind the joints in the concrete shows that the mass of the concrete has clear expansion and contraction effects, which are initiated and affected by thermal variations. There will also be deformations due to overloads and differential movements.

Each joint fulfils a purpose, such as to delay the inevitable deterioration of a structure until the end of its life span.

The isolation joints secure individually the joints between the different elements wall-floor, wall-wall, floor-column. In this way, the probability of structural damage to each of the elements is prevented.

On the other hand, in respect of construction systems for bridges, industrial facilities and pre-cast structures, expansion joints in concrete are very important. They will be exposed to high thermal fluctuations throughout their life span.

Expansion joints in concrete for bridges must be designed to absorb the dynamics of the structure. In particular, due to major variations in temperature to which the floor is exposed. It must preserve continuity in its rolling surface, in order to meet the demands of comfort and safety of vehicle traffic.


Like any other structural element, isolation joints of a concrete floor are subject to progressive degradation over time. This leads to the expected wear, which in turn requires measures to repair expansion joints.

Desgaste Juntas de dilatación en hormigón

Wear of joints depends on the environmental influence. It is also associated with surface abrasion, as this is the factor that causes surface disintegration, in its early stages.

The following types of abrasion are present in concrete joints:

Abrasion by traffic

This is caused by the friction of different transport vehicles on a floor. The joint resistance of a rigid floor depends on the characteristics of the used sealant. If the sealant is weak, wear by abrasion will lead to the formation of cracks and fissures, compromising impermeability.

Abrasion by erosion

Wind-blown sand particles impact the surface of the joints. The probability of wear from wind impact is very low, however, it depends on the environmental conditions.

Abrasion by moisture

In some cases water can transport sand at high speeds, for example in heavy rainfall. Like abrasion by erosion, abrasion by moisture does not imply a short-term wear of the joints, since it does not directly affect the adhesion of their components.

Abrasion by chemicals

Finally, we have the abrasion given by the interaction with chemical agents, such as some aggressive cleaning products. These can weaken the molecular structure of the sealant, causing it to disintegrate, exposing the structural elements to further wear.

Solar radiation is another factor that influences joint wear. Ultraviolet rays in particular alter the elasticity and plasticity of sealant substances. Due to the long exposure period they become stiff and unable to absorb friction and reduce deformations.

We consider that wear during the life span of expansion joints leads to the following consequences:


The most common consequence of joint wear is the formation of cracks and fissures. Cracks and fissures are the consequences of axial stresses in the concrete, triggered by overloads and temperature variations on the expansion joints.

Grietas en junta de dilatación

Cracks often appear in thin floors or slabs, making it difficult to dissipate and absorb the energy generated by axial and shear forces. They may also occur due to poor construction practices.


In the case of concrete constructions, it is necessary, as a preliminary measure, to carry out a thorough cleaning of the joint to be repaired, especially if it is open. The presence of dirt and dust alters the effectiveness of the sealant’s adhesion to structural elements.

In most cases, sealed expansion joints are the best construction option. They offer good mechanical protection and waterproof the structural elements.

The economic factor is important. However, investing in a state-of-the-art sealant will increase the life span of expansion joint and minimize maintenance periods. Elastomers have evolved technologically, becoming the ideal material for sealing expansion joints.