We get a lot of questions from property owners when it comes to foundations and foundation repair. One of the most asked is the title for today’s blog: How do we measure the elevation of a home?
First off, when we say “elevation” we aren’t talking about your home’s position relative to sea level – that fact is pretty inconsequential when it comes to foundation repair (at least around here where changes in elevation can be measured in inches). What we are talking about is the elevation within your home, determining if your home is level, specifically the foundation it sits on.
At Perma-Pier, we employ one of the most accurate devices on the market called a ZipLevel.
How does it work? ZipLevel explains it like this:
“ZIPLEVEL is a precision pressurized hydrostatic altimeter that levels and reads elevations by measuring the pressure developed by gravity acting on the net height of liquid between the MM and the BU. A water level is a hydrostatic level that establishes a level reference plane only much like a rotary laser.”
The backstory: In the 80’s this super smart guy & engineer Dennis Vories was planning on building a new office & lab in California. Back then, what they used to check foundation elevations were difficult because they required line-of-sight. Ever the engineer, Dennis thought this process could be improved upon, and since he couldn’t find a commercially available improvement, he came up with his own solution: a tool that employs a pressure sensor to measure broad areas of land digitally. After building his new lab, he perfected his invention by using a hydrostatic altimeter, which is now widely used in the foundation repair industry.
Cool right? This is exactly what our evaluators use to check the elevations inside the home. The reading is extremely accurate & will tell your evaluator if the home is dropping (-number), raised (+number), or within a safe reading.
So, your next question will naturally be: What is a “safe” reading?
Well, that question causes debate (even amongst Structural Engineers) depending on who you ask. But according to the FPA (Foundation Performance Association), as little as 3/4” of deviation in a 12 ft span is enough for concern. While that might not sound like much, think about it: what would happen to your average PVC pipe, surrounded by concrete, were to move ¾ of an inch? What would happen to your door frame? Your window frames? Your hardwood floors? That ¾ of inch change would make itself known in your home.
The Zip Level reading, along with other visible & non-visible signs helps us determine if you need repairs, along with how much & what type.
If you suspect you might need foundation repairs, what’s holding you back? We offer a FREE foundation evaluation. Why not schedule one today?