Leaks

Key Takeaways

  • A neglected elevator pit can hold two feet of water. Pits sit at or below the water table, and seasonal shifts in that table move the surrounding soil. That movement stresses the concrete, opens cracks at walls and base joints, and gives water a path in.
  • Access decides the repair method before anything else. Positive side waterproofing works from outside the wall and needs excavation room. On many commercial sites that’s impossible, because a garage, road, driveway, or property line sits directly against the leaking wall.
  • Negative side waterproofing works from inside the pit. It’s the more economical route when excavation isn’t an option. Crystalline technology, cementitious systems, and urethane injection are the common approaches, all applied from the interior surface.
  • Urethane injection performs in wet conditions. That matters, because an actively leaking pit is rarely dry enough for other methods. On poured concrete, the alternative is a fluid-applied, sheet, or bentonite-based membrane installed under the slab and across the exterior of the pit walls.
  • Block and brick walls fail differently. Soil movement shifts individual blocks just enough to open gaps, which shows up as leaking wall and floor joints or outright expansion joint failure. Injecting urethane grout directly into the cracks and failing joints is the fix.

Water leaks can cause elevator pits to harbor as much as two feet of water, especially in poorly maintained elevator pits. Elevator pits are mostly situated at or below the water table with concrete poured to create them. Seasonal changes can cause the water table to rise or fall, causing the soil to move and create issues with your building’s structure. There are numerous reasons why these pits may leak, and one of them is faulty or improperly installed waterproofing systems.

Faulty waterproofing can allow joints around the elevator pit to leak due to imperfections or cracks in the walls or base joints. Elevator pits may also begin to leak as the waterproofing material naturally ages. The waterproofing systems can wear down over time and allow leaks.

What You Can Do To Stop the Leak

The solution will depend on the type of structure you’re dealing with, which can either be poured concrete walls, masonry walls, or block walls.

Poured Concrete Walls

For concrete walls, water often seeps through cracks in the wall or at the base joints. You can counteract this issue through a urethane injection which works great in wet conditions. Another approach is to apply a fluid applied, sheet membrane, or bentonite-based membrane under the slab as well as on the exterior of the elevator pit walls. These waterproofing membranes act as barriers on the surface of the concrete to prevent water infiltration.

Positive side waterproofing or below-grade waterproofing requires access to the exterior wall surfaces and adequate space for workers. In some commercial buildings, however, it’s not possible to use this approach due to restricted access to the leaking area. It could be because garages, roads, driveways, or property lines adjoin directly with the leaking wall.

Negative side waterproofing provides a more economical approach when site restraints don’t allow for the excavation of a larger area around the elevator pit to waterproof the exterior walls. As a consequence, the waterproofing system will be applied from the inside to prevent water from seeping into the elevator pit. Common negative side waterproofing options include crystalline technology waterproofing, cementitious waterproofing, and urethane injection.

Block and Brick Walls

In the case of block or brick walls, soil movement due to water table changes can cause individual blocks or bricks to slightly shift, causing gaps to occur. Such gaps can result in issues such as leaking wall/floor joints or expansion joint failure. You can stop these leaks by injecting urethane grout directly into cracks and/or failing joints.

Ultimately, you need to work with an experienced waterproofing expert to effectively seal the leaks in your elevator pit and mitigate potential water damage and mold growth in your building. KPost Company is your trusted waterproofing contractor in Dallas, TX, and surrounding areas. Contact us today with any questions about waterproofing solutions for commercial and industrial properties.

FAQs

An elevator pit holds the buffer springs, the travel cables, the pit ladder, and in many buildings the sump and part of the control wiring. Standing water corrodes those components and shorts the safety switches that keep the car in service. Most elevator service companies will not enter a flooded pit, so a water problem turns into a downtime problem as well. The repair and code-compliance bill after the fact routinely exceeds what the waterproofing would have cost.

Yes. Elevator codes require pits to stay dry, and inspectors can red-tag a car for water accumulation, which takes the elevator out of service until the problem is corrected. Beyond compliance, water in the pit corrodes buffers, rails, and wiring, and it puts technicians in an unsafe space. Building owners generally find that the repair costs less than the downtime.

Often yes, using negative-side systems such as crystalline or cementitious coatings and injection grouting at active cracks and joints. Interior work is the practical route when excavating around a below-grade wall is not realistic on a developed site. The interior approach requires the wall to be sound, because these systems resist water pressure rather than replace failed concrete.

A sump pump manages water that is already inside, which keeps the pit usable, but it does not stop the intrusion. Relying on the pump alone means the surrounding concrete stays saturated and continues to deteriorate, and a power failure during a storm puts you right back in the water. Most owners use a pump as a safeguard alongside a waterproofing repair, not in place of one.

Most single-pit projects run a few days once the pit is dry and prepped, though active water has to be stopped before any coating goes down. The elevator is generally out of service during the work, so scheduling around building hours matters. Our below-grade waterproofing team handles the sequencing on occupied properties.
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