A Case of Too Much Water in the Wrong Place

Recently Foundation Technology was contacted to repair some cracks in a below ground concrete vault that holds the hydraulic lift mechanism within a Midas Muffler shop. It seemed ground water had been seeping in through cracks in both of the fourteen inch wide by eight foot deep vaults that held the shops hydraulic car lifts. Since this is a car repair shop, quite often oil and other automotive chemicals either spilled or leaked into the partially filled pit of water creating a toxic soup that needed to be pumped on a regular basis. Two to three hundred gallons of chemical laden water were being pumped from the vaults on a regular basis. Not only was this a costly endeavor, the water and chemicals also caused the hydraulic machinery to prematurely corrode and fail. Apparently this case of “too much water” had been going on for some time. Pumping was just considered a cost of doing business.

This all came to a head when the building was recently sold to investors. During the escrow period, commercial real estate inspectors determined the water intrusion problem was not only hazardous to the equipment but also to the surrounding soil as chemicals also leached downhill from the vault into the soil below. “The cracks had to be repaired” was the verdict and the lender requirement for the new buyer.

Multiple contractors offering low-cost crack repair solutions were contacted by the sellers’ agent to “seal” the vault from water intrusion. Foundation Technology was also contacted to provide a bid.

There was at least three feet of water with a sheen of motor oil, and hydraulic fluid covering during the initial inspection. The interior walls of the vault were oil and grease coated prohibiting both detailed inspection of the concrete floor and walls as well as attempting any type of epoxy or silicone crack repair as offered by the other contractors. It was determined that seepage from nearby uphill condominium units were the probable cause of the excessive groundwater. (The vault was directly adjacent to the condo project and at least fifteen to twenty feet lower in grade). This resulted in a fairly steady pressure flow of water seepage. It was also evident from the strong rotten odor coming from the vaults, that the soil below was being contaminated by chemical leaching. Simply filling the cracks or applying negative waterproofing was completely out of the question.

INJECTING POLYURETHANE FOAM TO CREATE A POSITIVE WATERPROOFING SEALANT.

HMI 401G being injected in the vault floor

Foundation Technology suggested injecting a plural component polyurethane foam capable of reacting in wet or high moisture applications to create a “positive” water sealant on the outside of the vaults. FT chose HMI’s 401G four pound foam for the project. 5/8” injection holes will drilled along the perimeter of the vault floors as well as on the walls where possible, (since access was fairly tight).

14 inches wide make for a tight working space

As the 401G polyurethane foam was injected in each port location, muddy water began to squirt up from the other holes. (As the foam expanded, it displaced the fairly large amount of water beneath the floor which quickly began to fill the vaults). We were actually surprised to see this amount of water coming from the injection port holes, especially in the drought conditions California is experiencing.

Both vaults were completely sealed in two days. After pumping by a hazmat service, the vault will be acid washed and injection holes filled with a hydraulic cement. Additionally a sealant will be applied to the interior to help contain the chemical leaching.

Foundation Technology offers engineered solutions and geotechnical construction/repair for commercial and residential applications. We specialize in soil stabilization, foundation repair, and helical/push pier installation. Foundation Technology provide services in California, Arizona, and Nevada.

For more information or to request a solution to your particular problem, please contact; Nicole Wahnon (nicole@foundationTechnology.com)
Foundation Tech, Inc.
d.b.a. Foundation Technology
25020 Avenue Stanford, Unit 110
Santa Clarita, California 91355
Toll Free. 855.650.2211
Local. 661.294.1313
www.FoundationTechnology.com