Elevator Pit Waterproofing: Causes, Membranes, Methods, and Protections

Written By Adam Paul - Waterproofing Expert

Elevator pit waterproofing is the process of applying waterproofing membranes and methods in the elevator pit to prevent water from entering the pit.

The elevator pit should be waterproofed due to groundwater seeping into the elevator pit, surface water penetration, cracks and joints in the pit walls and floor, higher humidity and condensation, leakages in the building, and flooding the building area.

You can use cementitious waterproofing, bentonite, and crystalline waterproofing for the elvator pit waterproofing process.

When you waterproof an elevator pit you should inspect the pit first. Then, you should prepare the pit surface and repair cracks and joints. Then, you can apply a waterproof membrane in the pit after choosing the right waterproofing membrane.

You should always follow the manufacturer's guidelines while you are applying it. Then, you should apply a protective coating in the elevator pit. When you are waterproofing the elevator pit, you should ensure a proper drainage system in the elevator pit. For better performance, you should maintain the elevator pit properly.

You can install a sump pump, inject grouts, use water stops, and use admixture waterproofing while concrete mixing are the best option for the elevator pit waterproofing. In order to protect an elevator pit, you should do regular maintenance, repairs, proper installations, control the environmental conditions and use high quality materials for the waterproofing process.

What is an Elevator Pit Waterproofing?

Elevator pit waterproofing is the process of applying waterproofing membranes and methods in the elevator pit to prevent water from entering the pit.

The elevator pit is the lowest place of the levator, and it is below the ground level. Hence, water can seep into the elevator pit easily due to seepage. Elevator pit waterproofing is essential to protect its components from water damage and corrosion and prevent potential operational failures. Waterproofing an elevator pit prevents water damage, ensures safety, increases durability and reduces the maintenance cost of the elevator.

What are the 6 Causes of Waterproofing an Elevator Pit?

These are the 6 causes for Elevator pit waterproofing

1. Groundwater seep into the elevator pit
2. Surface water penetration to the elevator
3. Elevator pit cracks and joints
4. Higher humidity and condensation in the elevator pit
5. Leakage in the building
6. Flooding the building area

1. Groundwater seep into the elevator pit

You should waterproof the elevator pit due to the higher water table and hydrostatic pressure in the ground. When the elevator pit is deeper, it is constructed below the ground. When the water table rises, hydrostatic pressure increases. As a result, water can easily seep into the elevator pit. Hence, you should waterproof it.

2. Surface water penetration to the elevator

You should waterproof the elevator due to rainwater and poor drainage system becuase surface water can be collected near the elevator pit and leak into the pit from cracks and joints of the concrete.

3. Elevator pit cracks and joints

You should waterproof the elevator pit due to cracks and joints in the elevator. Elevator pits are made of concrete. Concrete can be cracked and damaged due to thermal contraction and expansion and building settlements. Hence water can directly seep into the elevator pit through these cracks and loose joints. Hence, you should waterproof the elevator pit.

4. Higher humidity and condensation in the elevator pit

You should waterproof the elevator pi due to higher humidity levels. Humidity levels can be increased due to temperature fluctuation and moisture build-up that dampens the elevator pit walls.

5. Leakage in the building

You should waterproof the elevator pit to avoid leakages in the building. Unexpected leakages can happen due to plumbing errors through the roof walls and windows. Water can accumulate in the elevator pit due to these leakges. In order to prevent this you should waterproof the elevator pit and make pathways to remove water.

6. Flooding the building area

You should waterproof the elevator pit to protect it from natural disasters like flooding and heavy rain. Flooding can burst the pipelines and cause plumbing issues, so water will seep into the elevator pit.

What Waterproof Membranes Can be Used to Waterproof Elevator Pit?

3 Waterproof membranes for elevator pit waterproofing

1. Cementitious waterproofing
2. Bentonite waterproofing
3. Crystalline waterproofing

Cementitious waterproofing for elevator pit

Cementitious waterproofing protects the elevator pit from water infiltration using a cement-based coating. Applying cementitious waterproofing helps prevent moisture buildup in the structures, creates a seamless and effective waterproofing layer, and creates a long-lasting, cost-effective, and easy-to-apply.

Bentonite waterproofing for elevator pit

Bentonite waterproofing the elevator pit means creating a watertight barrier around the elevator pit walls and floor using a clay material called bentonite. Bentonite waterproofing creates a highly effective barrier, acts as a self-sealing layer, is durable and long-lasting, is environmentally friendly, and is easy to install.

Crystalline waterproofing for elevator pit

Crystalline waterproofing the elevator pit is a method used to transform ordinary concrete into a waterproof barrier for elevator pits using a special chemical admixture. Crystalline waterproofing improves integral protection, consists of self-healing properties, increases the durability of concrete, application to new or existing pits, and prevents moisture buildup.

How to Waterproof an Elevator Pit?

7 Steps to waterproof an elevator pit

1. Inspect the elevator pit: First, you should inspect and asses the elevator pit for existing water damage, cracks, or leaks. You should identify the source of water ingress to the pit. Then, check the condition of the concrete in the elevator pit and any existing waterproofing measures.
2. Prepare the elevator pit surface: You should remove any debris, dirt, and loose material from the elevator pit. Use a wire brush or a pressure washer for thorough cleaning. After cleaning, ensure the pit is completely dry before applying any waterproofing materials. Use fans or heaters if necessary.
3. Repair cracks and joints of the elevator pit: You should repair cracks and joints in the elevator pit. You can use a high-quality crack repair material, such as epoxy or polyurethane injection, to fill any cracks in the concrete. Ensure all construction joints are properly sealed with a flexible sealant or a water stop material.
4. Apply a waterproof membrane to the elevator pit: You should choose a suitable waterproofing membrane for elevator pit waterproofing.
   • You can use these waterproofing membranes, such as cementitious waterproofing slurry, a liquid-applied membrane, or a bentonite clay panel.
   • You should follow the manufacturer’s instructions for waterproofing application in the elevator pit. Typically, this involves applying multiple coats of the membrane to ensure a continuous waterproof barrier.
   • During the application process, you should ensure thorough coverage of corners and edges of the elevator pit.
     Install Water Stops
5. Apply a protective coating in the elevator pit: Use a protective coating such as an epoxy or polyurethane sealant to add an extra layer of protection. Apply the protective coating over the waterproofing membrane once it has cured. This will enhance durability and resistance to water.
6. Ensure proper drainage in the elevator pit: If the elevator pit is prone to water accumulation, install a sump pump to remove any water that enters the pit. Ensure that any existing drainage systems are functioning properly and are not blocked.
7. Regular maintenance the elevator pit: You should regularly inspect the elevator pit for any signs of water ingress or damage. Reapply waterproofing materials as needed and perform maintenance on the sump pump and drainage systems.

What are the Four Options for Elevator Pit Waterproofing?

The disadvantages of regular waterproofing, such as liquid waterproofing, sheet membrane installation, and other adhesive waterproofing, are that it is less durable, has high water pressure and high flow rate, takes much time to install, and has structural problems.

Install a sump pump system in the elevator pit

Installing a sump pump system in the elevator pit is highly recommended for higher water pressure and flow rate seepage.

A sump pump can accumulate and pump out the seeped water, which can be set up in a minimum period. It can control the higher flow rate of water leakages into the elevator pit.

This is more cost-effective and durable than applying a waterproofing layer on the elevator pit.

Inject grouts to the cracks and joints

Injecting grouts, such as PU grouts, epoxy resins, and acrylic gels, to seal cracks and joints can prevent water entry into the elevator pit.

Injecting and sealing cracks will last long and create a cost-effective water barrier that is easy to install.

Use water stops

Using water stops such as PVC, hydrophilic rubber, and bentonite water stops, you can create a multi-layer defense against water intrusion in the elevator pits. 

Water stops create a physical barrier, effectively blocking the leaks and providing a durable, long-lasting waterproofing solution.

Admixture waterproofing

Admixture waterproofing materials like hydrophobic, integral crystalline, and densifying create a permanent self-healing barrier within the concrete, protecting the elevator pit from water damage.

Also, admixture coatings do not degrade over time and are compatible with other waterproofing methods like crystalline treatments.

What are the Five Ways to Protect Elevator Pit Waterproofing?

These are the 5 ways to protect elevator pit waterproofing

1. Do regular maintenance
2. Do regular repairs
3. Install elevator pit waterproofing properly
4. Control environmental conditions near the elevator pit
5. Use high quality material for elevator pit waterproofing

1. Do regular maintenance of elevator pit waterproofing: You should regularly maintain the elevator pit by cleaning the area, sealing the membranes, and maintaining the sump pump systems in the elevator pits. You should fix any problem when you observe.
2. Do prompt repair for the elevator pit waterproofing layer: You should inspect the waterproofing layer periodically, repair the cracks and joints using injection methods, and fix membrane patchings. If the waterproofing layer is highly damaged, you should install a new one.
3. Install elevator pit waterproofing membrane properly: You should use the most appropriate elevator pit waterproofing membrane for your elevator pit according to its type. You can seek professional guidance to install the membrane properly.
4. Control the environmental conditions near the elevator pit: You should control and maintain the optimum environmental conditions near the elevator pits, such as humidity, ventilation, and groundwater accumulation. To control natural conditions, you can install a sump pump system, a proper drainage system, windows and doors, and proper grading near the elevator pit.
5. Use quality materials for the elevator pit waterproofing: You should use high-quality waterproofing products to waterproof the elevator pit. You can get the expert's help to choose the most appropriate high-quality products for the elevator pit.