(817) 398-8893

Soil Boring: The Essential First Step in Foundation Design

How Deep Should You Inject? Most Builders Get This Wrong

Sep 25, 2025

Soil reports aren’t just paperwork — they reveal the real risk beneath every foundation. In this breakdown, Todd Horn of ProChemical Soil Stabilization explains how geotechnical testing and PVR (Potential Vertical Rise) data show when and how soil will move. From lot-to-lot soil changes to reducing swell from 7% down to 1%, this is the science every builder, developer, and homeowner must understand before construction begins.

How We Use Precision Measurement to Plan Better Soil Treatment

Sep 23, 2025

Before any injection happens, precision soil measurement is key. In this post, Kelly from ProChemical walks through the exact software and approach we use to define soil treatment zones — ensuring long-term stability from the ground up.

Why Soil Boring Comes Before Foundation Design

Before you can design or pour a foundation, you need to know what’s beneath the surface. Soil boring — also called subsurface investigation — is the process of drilling into the ground to collect soil samples at regular depth intervals. These samples are then tested to reveal critical data: soil type, moisture behavior, strength, and Potential Vertical Rise (PVR). At ProChemical, we streamline this process by bringing a nimble boring rig directly to your site. The engineer observes every sample as it’s pulled, ensuring chain of custody is intact and results are defensible.

Why Soil Borings Matter

Foundation risk control

Expansive clays can swell when wet and shrink when dry, causing foundation heave, settlement, or cracking.

Data-driven design

Borings provide engineers with reliable data to size footings, design slabs, and determine if soil treatment or deeper supports are needed.

Schedule certainty

Traditional geotechnical rigs often take weeks to mobilize. Our lighter system cuts delays and keeps your project moving.

As Todd Horn explains:

“We can bore up to 15 feet in two-foot sections, hand each sample directly to the engineer, and preserve chain of custody all the way to the lab.”

Chain of Custody and Sample Integrity

According to the U.S. Environmental Protection Agency (EPA), maintaining chain of custody is critical to ensure soil samples are not contaminated, substituted, or mishandled during transport. Every handoff is logged, sealed, and documented so results stand up to scrutiny in engineering reports or legal disputes.

At ProChemical, we guarantee integrity by:

  • Having the engineer observe every sample extraction.
  • Transferring samples directly to their custody.
  • Reducing holding times so moisture and density remain accurate.
A skid steer-mounted soil boring rig with a visible hydraulic attachment, positioned on-site to drill 15 feet deep for fast, engineer-witnessed subsurface sampling used in foundation soil testing.
Geotechnical engineer and crew members reviewing a neighborhood lot map to plan post-injection soil sample locations during a site inspection.

Understanding Potential Vertical Rise (PVR)

PVR is a measure of how much a soil mass will swell upward when exposed to moisture. Expansive clays common in Texas can generate several inches of vertical movement if untreated.

  • A high PVR means higher foundation risk.
  • TxDOT guidelines set thresholds for acceptable PVR values in pavement and structural design. If limits are exceeded, soil treatment, overexcavation, or deep foundations are required.
  • Our goal is to deliver a 1% PVR benchmark, giving engineers predictable soil behavior to design against.

Faster, Cleaner, More Reliable Borings

Conventional geotechnical rigs are heavy, slow to set up, and easily delayed by site conditions. Our skid-steer mounted boring attachment allows us to:

  • Set up quickly, even in muddy or tight-access conditions.
  • Produce cleaner samples with less disturbance.
  • Hand samples directly to the engineer onsite.
  • Accelerate project schedules without sacrificing data quality.

This lean approach reduces disputes, improves lab reliability, and cuts costly downtime waiting for results.

Construction crew carefully hands a cylindrical soil core sample to the geotechnical engineer, maintaining chain of custody
Field crew removes final section of 3-inch Shelby tube containing a soil sample during post-injection boring on a residential lot.

Why Builders and Developers Trust ProChemical

  • Since 1992, ProChemical has been a pioneer in stabilizing expansive soils across Texas.
  • Our process treats the root cause in the soil, not just the symptoms at the surface.
  • We maintain transparency and defensibility, satisfying engineers, lenders, and municipalities.

Whether you’re building a custom home, subdivision, commercial site, or pool, soil borings and PVR testing are the first step to building with confidence.