Waterproofing Leaking Lift Pits and Elevator Pits
Power Coatings ltd specialise in waterproofing all types of pits, shafts, lift & escalator pits. It doesn’t matter if they are constructed from concrete, brick or concrete blocks. We can waterproof lift pits that are 100 years old, 50 years old or just 5 weeks old. We have tried and tested, proven solutions for them all.
There can be many reasons why water enters a pit. Usually the reasons are a mixture of the following:
- No tanking or waterproofing system installed
- The existing waterproofing system has been incorrectly applied or damaged during construction
- The pit is too old for any effective waterproofing system to have been originally installed
- Adjacent construction has altered or redirected the local water table
- A nearby water main has burst or drainage has blocked increasing ground water pressure
- The time of year wet weather can increase the water table higher than the water proofing
The typical systems we use for this type of work are:
- Dual component Polyurea resins
- Dual component epoxy resins
- Natural cement based render & waterproof grout technology, which is an environmentally friendly, fast setting, high early strength concrete repair material that starts to set in 35 minutes.
- Reactive single component hydrophobic polyurethane
- Our specifications usually involve a mixture of systems. This is dependant on the construction and extent of the problem.
Power Coatings waterproofing specifications are designed to form a permanent waterproof seal around the earth retaining side of the lift pit walls (positive side) or within the actual construction of the lift pit (negative pressure side).
These specialist repairs are carried out without any major disruption or dismantling of the lift mechanism. Ultimately this means less inconvenience, down time and cost to the client.
We install waterproofing systems to lift pits and escalator pits that are of any age. We have repaired and waterproofed buildings from new builds up to buildings of 100 yrs. old.
We carry out lift pit repairs to hotels, large company headquarters, commercial units, factories, schools, hospitals, large houses, sheltered housing schemes and care homes. We also recognise the problems that can be created when working in sensitive environments. We work with our client and our H and S team to ensure that the works we carry out are done so with minimum disruption.
Case Study: Health Care Home
The lift shaft had been suffering from water infiltration and flooding for approximately two years. This is a common problem in lift shafts. The problem was made worse due to structural defects within an adjacent drain. The infiltrated water regularly reached a level of .5m. The continual standing water caused corrosion to the substrate and a constant foul odour which permeated throughout the ground floor of the care home. The lift was situated next to the kitchen area which made the issue even more serious.
It was first necessary to repair the structural defects. A dual process was then chosen to deal with the infiltration issues. We selected a combination of rapid reaction polyurethane grout to halt the infiltration and ‘Ultracoat’ 100% solid epoxy coating system was chosen to seal, re-furbish and strengthen the base and walls of the shaft. ‘Ultracoat’ was selected because of its speed and ease of application and also its independently tested ability to adhere to damp substrates, ensuring that the lift could be back in service as quickly as possible.
Prior to the Ultracoat application, the substrate was cleaned and prepared, using high pressure water blast to clean and remove all coating and contamination, leaving a good surface key in the substrate. Following the cleaning, we injected a single component expanding polyurethane grout at regular intervals to stop the infiltration. A fast set hydraulic cement mix was used to install a 45 degree fillet at all vertical and horizontal 90 degree joints. The final part of the preparation was to spray a mild wash solution to kill off any bacteriological growth this was rinsed off and followed by a dilute acid etch to give the optimal surface to the concrete print to coating.
The chamber was then sprayed with the Ultracoat plural component, structural epoxy coating to a thickness of 3mm. After two hours the coating was inspected. The ‘Ultracoat’ had cured leaving a solid coating with no infiltration issues. (The lift was then put straight back into service).
Ultracoat’s superb proven ability to adhere to damp surfaces and prevent infiltration/exfiltration made it an ideal choice for the lift shaft conditions. The coating will deliver a long-term refurbishment solution and a warranty was provided to the customer. Independent testing of the product’s chemical resistance and other attributes gave the customer confidence in specifying this method of refurbishment. In addition, the speed of application and short curing time ensured that the lift was off-line for a minimal time period.