Quick Comparison
| Factor | Cosmetic Repair | Structural Repair |
|---|---|---|
| Purpose | Seal, waterproof, hide | Stabilize or restore structure |
| DIY cost | $30-150 | Not recommended DIY |
| Professional cost | $150-500 per crack | $3,000-15,000+ |
| Common methods | Injection, patching, paint | Anchors, straps, underpinning |
| When to consider | Stable, non-moving cracks | Active movement, bowing walls |
What Makes a Repair Cosmetic
Cosmetic repairs address cracks that aren't causing structural problems. The crack exists, but it's not getting worse, the wall isn't moving, and the only issues are visual or water-related.
My Situation
Vertical crack, about 8 feet long, near a basement window. Been there since 1978. Width hasn't changed in the four years I've monitored it. Wall is perfectly plumb. Both sides of the crack are level with each other.
The only problem was occasional water seeping through during heavy rain. That's a waterproofing issue, not a structural issue. I sealed it with polyurethane injection. Problem solved.
Common Cosmetic Situations
Hairline shrinkage cracks that are dry and stable. Vertical cracks near windows or corners that haven't moved in years. Small settling cracks that appeared decades ago and stopped. Any crack where the concern is appearance or minor water intrusion, not wall integrity.
Cosmetic Repair Methods
Epoxy or polyurethane injection to fill and seal. Hydraulic cement for patching visible areas. Waterproof coatings over repaired cracks. Paint if you don't even need to seal, just hide.
None of these add structural strength. They just seal, fill, and cover. That's fine when structural strength isn't the problem.
What Makes a Repair Structural
Structural repairs address actual failure or movement of the wall. Something is wrong with the wall's ability to do its job.
Gary's Situation
Horizontal crack across most of his back wall. Wall bowing inward 2.5 inches at the worst point. Crack width increasing over time. Visible daylight at the top where wall was separating from floor joists.
This wasn't cosmetic. The wall was actively failing. Sealing the crack would have done nothing because the wall was still moving. He needed wall anchors to stop the movement and potentially reverse it over time.
Signs You Need Structural Repair
Wall bowing or tilting. Crack width increasing over weeks or months. One side of crack shifted relative to the other. Doors and windows sticking or not closing. New cracks appearing. Separation at wall-floor or wall-ceiling joints.
Any of these means the wall is moving. Cosmetic fixes don't stop movement.
Structural Repair Methods
Wall anchors that tie the wall back to stable soil. Carbon fiber straps that prevent further bowing. Steel I-beams for severe cases. Underpinning to support settling foundations. These all add strength or stability that the wall has lost.
The Gray Area
Sometimes it's not obvious which category you're in.
Cracks That Look Bad But Aren't
My crack looked alarming to me. Eight feet long. Clearly visible. But it was old, stable, and the wall was perfectly plumb. Looked scary, was actually nothing.
Appearance doesn't determine severity. A dramatic-looking crack can be purely cosmetic, while a subtle crack in the wrong location can be structural.
When You're Not Sure
This is when you call a structural engineer. Not a foundation repair company. An engineer charges $300-500 to tell you the truth with no incentive to upsell.
I wish I'd called the engineer before getting three contractor quotes. Would have saved me weeks of stress and the headache of sorting through conflicting opinions.
The Monitoring Option
If you're not in a hurry, monitor the crack for six months to a year. Put pencil marks at the ends. Measure the width. Check monthly. If nothing changes, it's probably cosmetic. If it's growing, you need structural evaluation.
This is free and gives you actual data about your specific situation.
The Cost Difference
The spread between cosmetic and structural repair is enormous.
DIY Cosmetic
My $89 polyurethane kit sealed a 8-foot crack completely. Similar epoxy kits run $50-150. Hydraulic cement for patching is under $20. Even hiring someone for cosmetic injection is typically $200-500 per crack.
Professional Structural
Gary's wall anchors: $8,400. Helen's carbon fiber straps: $5,200. My uncle's underpinning job in another house: $22,000. These are major construction projects with significant labor and materials.
The Misdiagnosis Risk
A contractor quoted me $8,200 for carbon fiber straps on my cosmetic crack. That would have been pure profit for them and pure waste for me. Conversely, if Gary had just sealed his crack and hoped for the best, the wall might have failed entirely.
Getting the diagnosis right matters more than anything.
Making the Right Call
Based on my experience and watching Gary's situation.
Start With Observation
Mark your cracks. Measure them. Check them monthly. Time is usually on your side unless you're seeing obvious wall movement.
Get Independent Assessment
If you're worried or unsure, pay for a structural engineer before calling contractors. The $350 engineer fee is nothing compared to what you might save by avoiding unnecessary repairs.
Match Solution to Problem
Cosmetic problem, cosmetic fix. Structural problem, structural fix. Don't let a contractor sell you structural repair for a cosmetic issue. And don't try to seal your way out of an actual structural failure.
The right fix for the right problem. That's all there is to it.