Construction of Concrete Pools by NSG-N50 and Waterstop Tape
The following instructions are recommended by NSG Co. for constructing concrete pools:
Apply the lean concrete to level the floor of the pool after excavation and then reinforce the floor and walls of the pool. Pipe installation is also done at this stage.
To prevent water leakage at the floor-wall junction, then apply waterstop tape vertically on the edge of the walls, such that half of it sticks on the walls and the other half sticks on the floor.
It is recommended to use NSG-N50 to increase concrete strength, as well as the adhesion coefficient between concrete components, and reduce the concrete permeability.
This product also increases the service life of the pool and its resistance in the freeze cycle. NSG-N50 consumption amount must be between 1 to 2 percent of the cement weight.
For example, 7 liters of NSG-N50 per cubic meter of concrete should be added to the mixer if the cement content is 350 kg/m3, the required amount of NSG-N50 is equable to 2% of the cement weight. It should be noted that the mixture can be pumped into the structure after the concrete has been thoroughly mixed in the mixer for 10 minutes at high speed.
Don’t forget that concrete curing (repeatedly water spraying that is done with the aim of concrete curing) after the secondary setting of concrete (8 hours after concreting) is required for several days.
Traditional Construction of Concrete Pools by NSG-N50
Apply the lean concrete to level the floor of the pool after excavation and then reinforce the floor the pool. Floor reinforcement in this method can be implemented as a single strand (mesh). It extends to the walls to prevent cutting at the junction of the floor.
It is noteworthy that the water inlet and outlet pipes are also installed during floor reinforcement. One of the most important points in the pool construction is that the concrete placing of the floor should be before wall building. For the manual concrete placing on the pool floor, NSG-N50 is used. Mix NSG-N50 with water in a 1 to 10 ratio to make concrete. Note that in projects that economic efficiency is important, this ratio can be increased to 1 to 20.
After concrete placing on the floor of the pool, build the walls with cement blocks or bricks.
NSG-N50 is again used to make plaster for walls in a 1 to 5 ratio with water. Noting that in the economically important projects this ratio can be increased to 1 to 10. While the use of NSG-N50 in concrete placing on the floor and in the wall plaster reduces the surface permeability, it leads to the increased strength, the adhesion coefficient of the concrete, and the pool resistance in the freezing cycle. The structures such as pools that are considered as the reliance level of the insulation layer have a much longer service life.
Applying soft mortar in the under construction pools with NSG-B70 and NSG-S130
Soft mortar should be used on the plaster of the wall surfaces in the traditionally-built pools due to their high porosity. To produce this soft mortar, mix 1 volume unit of NSG-B70 with 3 units of water in addition to cement and the sifted stone powder or NSG-S130 (as an alternative of stone powder). There is no need to apply soft mortar for the floor concrete because it is smoother than the wall plaster. In order to fill the small pores and the capillary cracks that occur due to the shrinkage of concrete after drying, it is recommended to use a grout that is made by combination of 1 volume unit of NSG-B70 with 3 volume units of water, in addition to a smaller amount of cement and sifted stone powder or NSG-SI30. Due to the smooth surface of the concrete floor and walls in the pools with the reinforced concrete, the above-mentioned grout should be applied.
The important point before applying the soft mortar or grout mortar is to spray water on the concrete and mortar surfaces.
Sealing the under construction pool with NSG-PLC, NSG-Z90 and NSG-S130
NSG-Z90 is used as an alternative to traditional pool sealants. This product penetrates the concrete or mortar and becomes an integral part of the structure. Therefore, there is no probability of sealing exfoliation and separation from the pool surface. It is also highly resistant to the UV rays and can tolerate temperature fluctuations from -75°c to +350°c.
To apply the insulation layer, in the first step, combine NSG-Z90 with water in a 1:1 ratio and apply the resulting solution with a brush or pistol twice. Note that the second coat should be done when the first coating dries completely. In the second step, prepare the NSG-Z90 and water solution separately and combine 1 volume unit of cement with 2 volume units of sifted stone powder or 2 volume units of NSG-SI30 as a substitute for stone powder individually. In the end, apply the resulting grout from the combination of liquid and powder twice. Again, note that the second coat should be done when the first coat dries completely.
In order to prevent cracking of the applied insulation in the corners and construction joints under the water force and structural vibrations, use NSG-PLC mesh on each coat of the grout. Do this step twice.
It is important to allocate enough time for the insulation layer to dry (between 5 and 12 days depending on the weather conditions) before the pool intake.
Sealing and restoring the pool with the final colorful surface
After water draining, remove the loose and damaged spots as well as the old paints from pool surfaces. Then, make the structural cracks V-shaped. First, dilute 1 volume unit of NSG-N50 with 2 volume units of water and apply it with a brush on the cleaned parts. Also, mix 1 volume unit of cement with 2 volume units of stone powder paint or NSG-SI30 as an alternative of the stone powder. In the next step, add the powder mixture to the pre-made solution and repair the above mentioned spots with the produced repair mortar.
The surfaces of the walls and the floor of the pool become rough with paint and need to be softened before applying the insulation layer. To make a soft mortar, combine 1 volume unit of cement with 2 units of sifted stone powder or NSG-SI30, then add the powder part to the solution. Use this soft mortar on the floor surfaces and pool walls.
Wetting down the cement surfaces before applying the soft mortar and also after it dries is necessary in order to reduce cracking and prevent it from exfoliation.
NSG-Z90 is used for applying the main sealing layer based on the following application procedure:
- Mix NSG-Z90 with water in an equal volume ratio (one to one) and apply this solution on the surfaces twice with the time interval of drying the first coat.
- Prepare 1:1 solution of NSG-Z90 and water, and combine it with the mixture of 1 volume unit of cement, 2 volume units of sifted stone powder or NSG-SI30. Apply the resulting material on the surfaces twice. Note that the second coat should be done when the first coat dries completely.
- Repeat step 1.
Note: If the final surface is planned to be colored, mix a diluted 1:1 mixture of NSG-Z90 with 3 scales of acrylic paint, and apply this mixture for the surface twice. Again, note that the second coat should be done when the first coat dries completely.
Sealing and restoring the pool with the final tile surface (without dectruction) with NSG-Z90, NSG-S130, and NSG-PADAB
In sealing the tile-surface pools it is very important to check if there is any probable facture in the pool structure. Usually, there is water leakage in the pools with more than 10 cm fractures. The only solution in such cases is to remove the tiles.
In the less water leakage cases first, wash the interior surfaces of the pool with a diluted solution of hydrochloric acid with a plastic brush. Use wire brushes to remove the loose joints.
After the rinsing of the surface of the pool and drying of the surfaces of the joints first, mix NSG-Z90 with water in a 1:1 volume ratio and apply it on the joints with a narrow brush. If the tiles have smaller dimensions, apply the solution with a brush on all surfaces, and remove the excess solution from the surface of the tiles with a cleaning cloth after about 10 minutes i.e. when NSG-Z90 has been infiltrated into the joints.
In the second step, combine 1 volume unit of NSG-Z90 with 1 volume unit of water. In addition, mix separately 1 volume unit of white cement with 2 volume units of NSG-SI30. Then, apply the resulting grout from adding the powder phase to the liquid phase with a brush on the joints according to the above-described instruction.
In the third step, repeat the first step.
In the end, use NSG-PADAB sealing paste to fill the joints between the tiles and the metal bases of the ladder or around the frame of the lights inside the pool (heterogeneous joints).
In the third step, repeat the first step.
Tiling and pointing the pool with NSG-B70, NSG-Z90 and NSG-SI30
A major problem with tiling ready adhesives is that they become softened in a long time exposure with water, leading tiles bloating and sometimes separating from the surface.
It is recommended to use NSG-B70 to make tile adhesive with a very high sealing coefficient and adhesion. To do so, mix NSG-B70 with water in a 1 to 3 ratio and combine 1 unit of cement with 2 sifted stone powder separately. Then mix the powder phase to the liquid phase to make a honey-like mortar, by which tiles can be installed. If tiling is done with 2×2 cm tiles, it is better to use white cement instead of black cement to make tile adhesive.
Another advantage of NSG-B70 is the very high tolerance to temperature fluctuations. It also prevents tiles separation from the under water pressure surface.
In the next step, mix 1 unit of NSG-Z90 with 1 unit of water as the liquid phase and 1 unit of cement with 2 units of NSG-SI30 as the powder phase. Then mix the two phases and the resulting mixture for pointing the joints. The use of NSG-Z90 in the composition of the pointing grout increases the joints’ resistance to corrosion and greatly reduces the permeability of the joints.