Foundations move. (Doesn't always mean yours needs repair.)
TLS Foundations Reference

Why Foundations Move in New Mexico

And why many don't need underpinning.

Foundations don't "fail" because they crack. They move and crack because the soil supporting them changes. In New Mexico, that change is almost always driven by moisture — too much in one place, not enough in another, or introduced where the ground never expected it.

Underpinning is one possible response to foundation movement. It is not always the right one. Many homes in New Mexico show signs of movement that can be managed without structural intervention — through drainage correction, leak repair, or simply monitoring over time.

This page explains the full range of reasons foundations move, when underpinning is the appropriate response, and when it isn't. It is written for homeowners who want honest answers and for the engineers who serve them.

It is not a diagnostic tool. It does not replace professional evaluation. It gives you the vocabulary to ask better questions — and to recognize when the answers you're getting don't add up.

Foundation Movement Is Not the Problem — It's the Result

Every foundation problem traces back to one of three things: the soil changed behavior, the moisture regime changed, or the load on the foundation changed. Sometimes two at once. Sometimes all three.

The soil beneath your home is not static. It responds to water, weight, temperature, and time. When those conditions shift — a pipe leaks, drainage patterns change, a new addition adds weight — the soil responds. The foundation follows.

Understanding which of these three drivers is at work is the first step toward knowing what to do about it. That understanding comes from investigation, not from looking at cracks.

What You're Seeing vs. What May Be Happening

Foundation symptoms look similar. The causes behind them are not. Here's what the most common signs may point to — and why the first step is always investigation.

What You See
What May Be Happening
Is Underpinning the Answer?
The Honest First Step
What You SeeDiagonal cracks, doors sticking seasonally
What May Be HappeningSoil volume change — expansive clay.
Is Underpinning the Answer?Rarely first step. Moisture management often resolves.
The Honest First StepEvaluate drainage, irrigation. Learn about expansive clay → | Full article →
What You SeeSudden settlement after heavy rain or snowmelt
What May Be HappeningCollapsible soil — structure collapses when wet.
Is Underpinning the Answer?Often yes, but water source must be stopped first.
The Honest First StepFind and fix water source. Collapsible soils → | Article →
What You SeeLocalized cracking near kitchen/bath
What May Be HappeningPlumbing or sewer leak beneath slab.
Is Underpinning the Answer?No while leak active. Repair first.
The Honest First StepPressure test water lines; camera sewer. Plumbing leaks →
What You SeeCracks on sloped lots or near arroyos
What May Be HappeningLateral soil movement or erosion.
Is Underpinning the Answer?Not alone; slope must be stabilized.
The Honest First StepEvaluate slope, drainage, arroyo proximity.
What You SeeHairline cracks unchanged for years
What May Be HappeningConcrete curing shrinkage or thermal movement.
Is Underpinning the Answer?No.
The Honest First StepMonitor; seal if desired. FAQ →

The Cause Library

Foundation movement in New Mexico has many causes. They are organized here by mechanism — what is actually happening to the soil — because understanding the mechanism is the prerequisite for understanding the fix.

Every cause described here requires professional evaluation to diagnose correctly. No visual inspection alone can distinguish between them.

Group A — Loss of Support

The soil can no longer carry the weight. Underpinning is often the right answer.

A2. Poorly Compacted Fill
A3. Cut-and-Fill Transition Movement
A4. Landfill and Undocumented Fill Sites
A5. Subsurface Erosion and Soil Piping
A6. Consolidation of Deep Alluvium
A7. Bearing Failure from Load Changes

Group B — Soil Volume Change (Active Zone)

Soils expand, shrink, or react chemically with moisture. Underpinning is often NOT the first response.

Beneath every foundation, moisture fluctuates seasonally — this is the active zone. Most movement originates here, driven by moisture.

B1. Expansive Clay Soils (including Mancos Shale, Sulfate Heave, Caliche)

Group C — Water and Moisture Drivers

Water is the trigger for nearly every cause. These cases are primarily water problems, not soil problems.

C1. Plumbing and Sewer Leaks Beneath Slab
C2. Poor Surface Drainage & Concentrated Runoff
C3. Irrigation and Landscaping
C4. Tree Root Moisture Extraction
C5. Altered Moisture from Adjacent Development

Group D — Deep Geologic Hazards

Instability deeper or broader than surface corrections can address. Some unique to NM.

D1. Evaporite Dissolution & Karst Subsidence
D2. Hillside Creep & Slope Instability
D3. Seismic Activity & Rio Grande Rift
D4. Regional Groundwater Changes
D5. Arroyo and Flash Flood Erosion

Group E — Construction & Design Deficiencies

Not all movement is soil — some is design or materials failure.

E1. Inadequate Foundation Design
E2. Inadequate Reinforcement & Structural Capacity
E3. Post-Tension Cable Failure
E4. Prior Repair Failure
E5. Adobe & Non‑Standard Foundations

Group F — Site & Environmental Triggers

F1. Frost Heave
F2. Vibration-Induced Settlement
F3. Burrowing Animal Activity

When Underpinning Is Not the Answer

This is the section no other contractor publishes.

Cosmetic cracking from concrete curing No repair needed.
Thermal movement Cracks that open/close seasonally are normal.
Uniform settlement that has stabilized Monitor.
Active heave without net settlement Moisture control, not piers.
Moisture problems not yet corrected Fix water first.
Slab curling Slab replacement or grinding.
Addition differential movement Isolation joints.

The honest alternative for many: improve drainage, repair leaks, manage irrigation, stabilize slopes, reinforce concrete, or monitor. Many New Mexico homes can be managed without structural intervention.

What the Industry Gets Wrong

Moisture is the primary driver — not soil type alone. Moisture control doesn't sell piers, so it's underemphasized.
Underpinning without moisture correction usually fails. Biggest unspoken truth.
Collapsible soils are invisible in national training. In NM, collapsible soil is as common as expansive clay.
Heave and settlement look identical but require opposite responses. Underpinning fixes settlement, not heave.
Contractors sell solutions before diagnosing problems. The cause is assumed, not investigated.
Piers can fail — and nobody talks about it. Skin friction, caliche cap failure, corrosion.
The dry season creates a sales opportunity. Many gaps close during monsoon — honest contractors say so.
'Lifting' is not always the right goal. Sometimes arresting movement is more honest and less destructive.
Geotechnical investigation is treated as optional. Visual-only repairs fail when the cause is deeper.
Post-repair monitoring is rarely discussed. No benchmark, no follow-up — no way to know if it worked.

The Intervention Spectrum

Monitor Minor, historical, within tolerance.
Moisture & Site Correction Drainage, leaks, irrigation, grading.
Soil Improvement Grouting, void fill, chemical stabilization.
Structural Reinforcement Carbon fiber, rebar, slab strengthening.
Underpinning Deep piers to stable material.

A company that only offers the last option will recommend it for every problem.

Why Evaluation Comes First

No reliable repair recommendation can be made from symptoms alone. Cracks, tilting, sticking doors can be caused by a dozen different mechanisms.

A proper evaluation includes site history, elevation surveys, soil borings, moisture source identification (including sewer camera), and structural analysis. It's the only honest path to a solution that actually solves the problem.

TLS Foundations requires this step. Our affiliated geotechnical firm, Sandia GEO, operates independently from repair sales — evaluation driven by evidence, not by what we need to sell.

Have questions? We're happy to talk — no pressure, just answers. Contact TLS Foundations →

Prevention and Maintenance

  • Maintain positive grading directing water away from foundation.
  • Extend downspouts at least 6 feet from foundation.
  • Keep irrigation and plantings away; establish 3-foot dry buffer zone.
  • Repair leaks promptly; test plumbing (including sewer lines).
  • Avoid over-watering on expansive or collapsible soils.
  • Monitor cracks, doors, floors seasonally; photograph and date.
  • If you remove a large tree, watch for soil rebound (swelling).

None of this costs much. All of it matters.

The Honest Caveat

This page explains conditions that can lead to foundation movement. It is not a diagnostic tool. Several different mechanisms can create identical-looking cracks. Only site-specific investigation confirms what's happening beneath your home.

Determining the correct response requires understanding whether movement is ongoing, what's driving it, and whether that driver can be corrected without structural intervention.

This page gives you vocabulary to ask better questions. It does not give you the ability to diagnose your own home.

Ready when you are

Every foundation is different. Yours needs its own answer.

Text or call — you reach the owner(s).

Text Send a text → Usually same day
Call (505) 991-4180 The owner(s) answer
Location Albuquerque, New Mexico The state is our office