Mau West Project · Basement Waterproofing for a commercial development in Thika

The Task: Waterproofing the basement.

 

The Challenge:

 

Basement of the proposed commercial development in Thika

Basement of the proposed commercial development in Thika

 

The commercial development in Thika District provided various challenges during construction as the area is swamp, thus there’s a considerable amount of ground water. The commercial development had a deep basement and the excavation was a magnet for the swamp water.

The developer of the commercial building had to do a lot of de-watering throughout the construction process-by continuously pumping out water from several sumps that were excavated at a much deeper level than the basement level.

 

Cracked slab

Notice the cracks at the bottom of the column

 

Flooded basement

Flooded basement

 

 

The Solution:

 

The developer decided to cut the slab in some sections, placed french drains under the existing slab, then made good the cut areas.( The french drains collected the ground water and drained it into a sump). Then, another slab, mixed with PENETRON ADMIX was cast on top of the existing slab.

Dry basement

 

 

Sump

 


 

Conclusion

    During the wet season, the developer will always have very high energy bills as the pumps in the sump collecting water from the french drains will be running throughout. Considering the area is swampy there will always be water draining into the sump.Running and maintaining the pumps is a cost the developer will have to bear many years to come.

If the area was sloping, the french drains would be able to drain the ground water to  a lower ground and the water would flow away by gravity. This would be very economical as no pumping would be involved.  Unfortunately the basement is in a flat area and all existing drains are much higher than the french drains. Therefore, all the water has to be pumped.

The best solution for this basement would have been to design the floor slab and retaining walls to be able to withstand the highest hydrostatic pressures of the ground water. This would mean the cost of concreting the basement would be almost double the cost of the existing basement but this would be a one -time cost. The developer would not experience future recurring  costs of pumping out ground water.

Featured Products

Penetron A surface-applied, integral crystalline waterproofing material, PENETRON is used for waterproofing and chemical protection at above and below ground level. PENETRON is applied by brush or spray to either the positive or the negative side of the concrete and in the presence of moisture penetrates deeply into the structure. The ensuing chemical reaction fills micro cracks, pores and capillaries with an insoluble crystalline formation, which prevents water and water-borne chemicals from entering, even under high hydrostatic pressure. Cracks that develop during the lifetime of the concrete are resealed by PENETRON, resulting in permanent concrete protection.
Peneplug A rapid-setting, crystalline-based, cementitious compound designed to stopping active leaks even under high hydrostatic pressure. PENEPLUG is recommended as a waterproof plugging mortar or where rapid-setting is required.
Penetron Admix A 3rd generation crystalline admixture in powder form that is added to new concrete during batching. Once inside the concrete, it reduces concrete permeability by permanently sealing micro cracks, pores and capillaries and effectively protecting the concrete against water penetration and the effects of deterioration, even under high hydrostatic pressure. PENETRON ADMIX provides projects with self-healing concrete with the ability to reseal cracks that develop during the lifetime of the concrete