During heavy rainfall, water can enter the shaft pit of an elevator. In the picture: The shaft pit before waterproofing measures were taken. (Photo: © Kewabo)
September 2025
Given the current heavy rain events, lifts are repeatedly flooded. All this not only involves risks for the lift itself but possibly also for the users. What measures are advisable?
By Frank Kanschat
For example, if heavy rain leads to lifts being flooded, the operators and maintenance companies responsible need to be cautious since anything is possible, from people being trapped to electrical shocks. In addition, flushing of the oil receiver tanks can result in an oil-water mixture in the pit. This is classified as a "hazardous" material and has to be disposed of at great expense.
Avoiding considerable damage to live components from water penetration is difficult and causes additional costs. The causes here can be found for the most part in the building fabric, which is not designed for severe rain. Even a waterproof concrete foundation pit fails in many cases since it simply gets flooded. A rising groundwater table will do the rest and press the water from below and the sides into the shaft.
The floor wall connection is not always at fault but rather water seeping into the shaft pit via the separating layer between the floor screed and floor plate. Many companies offer grouting. But this is just a blanket solution that in most cases is insufficient or cannot be implemented due to the fabric. Every case must be considered and handled as an individual case.
In general, in the case of weather-proofing measures care must be taken that the seal selected is compatible with the basic standard EN 81. This means that the protective space in the pit area may not be restricted, for example by a wall structure that is too thick or excessive hollow spaces in the floor wall connection. The final coating of the pit must comply with WHG (Water Resources Act) Section 6 (Duty of care for protection of waters) and also be able to replace an oil-proof coat of paint.
A complete seal is advisable but not always necessary. A partial seal is often sufficient to remedy the problem. Pit installations also have to be demounted in order to create a seal behind or beneath them, including the dowel holes to be sealed. The same applies to Halfen struts that have to be inserted in order to create corresponding tightness here too. Cable or hose bushings in the pit area have to be considered too since they normally represent the largest openings.
In general, the measure selected should produce complete a seal that withstands water pressure of 4 bar and is backed up by a guarantee of up to ten years. Partial seals do not help here or are not at all durable, especially since most providers do not provide any kind of guarantee.
In such cases, commissioning a specialist company with detailed knowledge in the field of lift technology and capable of evaluating and handling the technology is important.
More informations: https://www.kewabo.de/
The author is a consultant for damage analysis and specialist for lift technology at Kewabo. The company is specialised in sealing damp walls and floors in basements and on the ground floor.
Digitalpaper
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