Spend any amount of time driving around the country in North Texas on a rainy day and you'll witness firsthand the sticky mess that our soil becomes when it gets a little wet. This soil doesn't just make cars and shoes muddy, it can cause havoc for the construction industry. Trying to build in and on clay is extremely difficult because it is highly unstable and shifts frequently. It is important that your builder understands this and takes steps to stabilize the soil prior to pouring any concrete.
Texas is a Blend of Valor and Swagger...and Clay
North Texas, which includes the Dallas/Fort Worth Metroplex, is part of what is known as the Blackland Prairies, an area of land that extends all the way from Bonham to San Antonio. Blackland Prairie is comprised of deep, dark-grey to black alkaline clays which floods and drains quickly, alternating between sticky, squishy mud and rock hard, concrete-like dry soil that cracks in the sun like something out of an old Western. This extreme fluctuation can make building a permanent structure tricky, because of the radical way the soil expands and contracts with the water it takes on. Have a look sometime at some of the older homes built on pier and beam foundations around the Metroplex- the owners of these home must have their "foundation" adjusted every few years, otherwise they develop cracks in the walls, ceilings, and floors. Too much neglect in this area, and your house could come crashing down on you!
But I Thought a Pool Was Basically a "Swimming Hole"
Just because we are digging down and not building up doesn't mean that pool builders don't also have to contend with the instability that is North Texas soil. In many ways, we have to work even harder, because the concrete (or gunite, as it's known) must not only hold its form in the ground, but must also support upwards of 20,000 gallons of water within the pool itself. That's a lot of pressure, and when you don't have a stable earthen support around it, the burden falls to your builder to ensure that the necessary steps are taken to create an artificial support system and keep your pool whole.
Is This Why My Builder Wanted a Soil Study?
Yes! Some clients need to have a geotechnical engineer come out and test the soil so that their builder can know from the get-go if your soil will need any extra support before they start digging. Not every client needs this, but many do, and your builder will know right away which ones most likely do, based on where you live. Knowing upfront what to expect helps your builder plan the construction schedule so that there are no costly surprises along the way.
How Do You *Add* Stability to This Blackland Prairie Mess?
The most common way to stabilize the soil in North Texas is through a process called Potassium Injection Stabilization. Basically, these big machines literally inject the ground with potassium ions which then binds with the clay, creating a sturdier soil. It is cost effective and permanent, and will protect your investment and save you from future headaches.
Texas has 4 Seasons- Drought, Flood, Blizzard, Twister
Well, not much we can do about that last season, but for the first three, knowing your soil and taking preventative steps to reinforce it can help keep your pool in one piece while our weather yo-yos between scorching heat, impromptu snow, and torrential rains. Be upfront with your builder about concerns that you have, and if you are confused about anything, make sure to ask questions. Your builder is the expert and is there to share his or her expertise. No builder wants to put their blood, sweat, and tears into building something beautiful only to have to come back in 6 months or a year to tear it down and start anew, especially if they could have done it right the first time. Honesty is always the best policy, and in this case, it can save you (and your builder) thousands of dollars and weeks of frustration.
Happy digging, y'all!