One of the most common questions we hear in regards to our concrete lifting division is, “How do you keep from over lifting?” Obviously, foam is expanding under the surface and in most cases; the expansion process cannot be seen. So, any question regarding over lifting is a valid one and one we are happy to address.
We have three different ways to monitor our concrete lifting:
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Dial Indicator
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Zip Level
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Experienced Technician
Dial Indicator
Once a void is filled under a slab, the soil and concrete are connected by foam. This creates positive pressure, which creates movement. Our dial indicator measures movement within 1/1000th of an inch. We place the dial indicator needle on one slab and the base on the adjacent slab. When positive pressure is reached and movement starts, our dial indicator notifies us before the naked eye can.
Zip Level
Once positive pressure has been indicated with the dial indicator and movement is steady, we watch our zip level. A Zip Level is a bubble free altimeter that measures elevation. The level is “zeroed” on the desired elevation and then placed on the slab being lifted. Elevation change (slab lifting) is shown with each 1/8th inch of lift achieved. Lifting continues until the zip level reaches desired elevation. Or in other words, until the concrete slabs are level.
Experienced Technician
Technology and tools area great and certainly make our lives easier and our work more precise. But we could not make it without experienced technicians. When lifting concrete, a lot of indicators come from the pressure felt at the injection gun. A trained technician knows how to tell if an injection point is full just based on the way the material reacts as it enters the injection site. If you know your material and how concrete reacts (or doesn’t) under pressure, the readings from a dial indicator and zip level make more sense.
Lifting concrete requires a large majority of your God given senses as well as a few man made tools. Helms Polyfoam is proud to report that we employ the best of all in these categories.
Is there anything you want to know about polyurethane resins, their uses, or how they are monitored? Call 601-966-7821 or submit a website inquiry. Who knows, we may write a blog about it!