Saturday, December 15, 2007

There's Water In My Elevator Pit

Recently one of our sales engineers was faced with the task of helping waterproof an elevator pit. The basic construction of a pedestrian elevator includes a pit 10'-20' below the last floor for counterweights, wiring and a giant hydraulic safety stand. The building this three-stall elevator pit was located in was next to a large rocky limestone hill and about 200' from a river. Wall construction was poured concrete in good to excellent condition.
While the pit was set up with an exposed cove drain tile system around the wall leading to the sump pump the rest of the floor was not protected and over time water was noticed coming through some of the bolt holes drilled into the floor holding up the tracks for the elevator. In addition there were several areas around the seam at the wall and floor that water was creeping through including a larger leak the size of a pencil that water was coming out of in a steady stream.

Using our exclusive bentonite hydroclay injection system the installers at Great Lakes Waterproofing tackled the problem by drilling holes near the leaks and injecting our waterproofing blend of bentonite hydroclay. Right away the flow of water had stopped at the bolt holes. The next step was to waterproof the perimeter, not an easy task as it was flowing over a gallon of water into the sump every minute. Our waterproofing blend of bentonite hydroclay is an all natural product that stays flexible throughout it's lifespan, the self-sealing nature of the clay is perfect for this application that has many dynamic water forces at work.

Once again our waterproofers drilled holes every few feet straight down through the concrete into the sand and water. Working fast to make sure the sump pump was not overwhelmed by the water coming in through the new holes, the Great Lakes Waterproofing Team pumped bentonite waterproofing into all the holes and capped them off with hydraulic cement. for a permanent waterproofing solution.

Another elevator pit we waterproofed contained a large hydraulic lift for it's industrial elevator. Typically the shaft is buried as deep as it's height above the floor, in this case over three stories.
The old lift had started leaking hydraulic fluid and needed to be replaced. The floor around the old shaft was broken out, the new shaft installed and concrete was poured around the new shaft. Several areas of repaired concrete around the new shaft developed leaks. The elevator pit floor was next to a river and 5-10' below the surface of the water, developing a lot of hydrostatic pressure on the exterior of the elevator pit. The pit had 2-3" of water and the sump pump was running continously 24 hours a day.

Once again we drilled through the concrete floor and pumped in our waterproofing blend of bentonite hydroclay. Several areas around the pit needed attention. Once the hydroclay was installed and the pit started to dry we closed all the holes off with hydraulic cement. In addition to drying up the elevator pit, the industrial sump pump is now dormant.

Things are looking good now in these dry elevator pits, this is another example of bentonite waterproofing we can do at a fraction of the cost the other guys charge to divert the water.