When to Call a Pro: Signs Your Concrete Needs Expertise
New Hampshire has harsh winters, salty air, and tricky soil, which make concrete work challenging. Concrete is key for your driveway, foundation, or patio but isn’t invincible. Ignoring minor issues can lead to costly repairs or even safety hazards. Let’s break down the red flags that scream, “Call a pro!” and how to vet them like a seasoned DIYer (or when to hand them off to the experts).
Why New Hampshire Concrete Is Extra Vulnerable
Concrete in New Hampshire battles:
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Freeze-thaw cycles: Water seeps into cracks, freezes, and expands, worsening damage.
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Road salt: Corrodes surfaces and accelerates spalling (flaking).
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Clay-rich soil: Shifts with moisture, causing floors to sink or heave.
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Coastal humidity: Promotes mold, mildew, and rust stains in reinforced concrete.
New Hampshire’s climate is a concrete killer. Regular inspections are non-negotiable.
1. Cracks: The Silent Concrete Floor Saboteurs
Not all ruptures are created equal. Here’s how to decode them:
| Crack Type | DIY or Pro? | Risk Level |
|---|---|---|
| Hairline (⅛” wide) | DIY sealant | Low |
| Vertical (¼”+) | Pro | Moderate |
| Horizontal | Pro ASAP | High |
| Stair-step (foundation) | Pro | Critical |
The Milford Home Concrete Repair Sale Disaster
In Milford, New Hampshire, a homeowner nearly lost a buyer due to potential issues with cracks in the garage foundation. A pro discovered eroded soil under the unsightly concrete, requiring helical piers to stabilize it. The cost: $8,200. Lesson: Horizontal gaps often signal soil failure or hydrostatic pressure—don’t wait.
Pro Tip: Tape a penny into crevices. If it fits, call a pro.
2. Spalling & Surface Breakdown
Spalling resembles concrete acne—chunks flake off, exposing the rough aggregate. Causes:
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De-icing salts (common on New Hampshire driveways).
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Poor mix quality (too much water weakens concrete).
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Freeze-thaw damage.
The Amherst Structural Repair Driveway Debacle
An Amherst family’s 2-year-old driveway crumbled like feta cheese. The culprit? A contractor skimped on air-entrained concrete (a must for New Hampshire winters). Repairs cost $6,500.
DIY Fix: Small spalls can be patched with hydraulic cement and sealer. Hire a pro to resurface or replace for large areas (>1 sq. ft.).
3. Uneven Slabs: Trip Hazards & Structural Red Flags
Sinking or heaving concrete damage isn’t just ugly—it’s a liability.
Causes:
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Poor compaction during installation.
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Eroded base (common near New Hampshire’s wetlands).
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Tree roots lifting floors.
When to Worry:
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Trip hazards (>¾” height difference).
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Pooling water near foundations.
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Doors/windows sticking (indicates shifting).
PolyLevel contractors say that 60% of jobs have cement floors that sunk by 1–3 inches because of frost heave.
4. Water Intrusion: Mold, Mildew, Stains, and Mayhem
New Hampshire’s avg. Rainfall is 44″ annually—and concrete is a sponge.
Signs of water damage:
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Efflorescence (white, chalky residue).
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Musty odors in basements.
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Rust stains on reinforced concrete.
Pro Tip: Install a WaterGuard drainage system. TC Hafford offers a $4,800 option in North Hampton to help redirect pressure washing and rainwater.
5. New Construction Woes: Don’t Trust Concrete Blindly
Even new builds aren’t immune.
Red flags:
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Cracks within 1 year.
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“Crazy paving” (random ruptures resembling broken glass).
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Soft spots (indicates poor curing).
The Hudson Foundation Repair Contractors’ Nightmare
A Hudson homeowner’s brand-new foundation sank 4 inches due to improper compaction. Erickson Foundation Solutions stabilized it with steel push piers ($12,000).
Checklist for New Concrete:
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Verify 4,000+ PSI mix.
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Ensure proper rebar spacing (12–18″).
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Require a 10-year warranty.
Saving a Sinking Dunbarton Patio
Problem: A 20-year-old patio in Dunbarton sank 2″, directing rainwater into the basement. Solution: PolyLevel foam injection lifted the concrete in 4 hours ($2,100).
Outcome: No more flooding and restored curb appeal.
How to Choose the Right Pro: 5 Must-Ask Questions
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“Are you licensed/insured in NH?” (Avoid uninsured crews—familiar with seasonal markets.)
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“Can you provide a moisture test?” (It prevents post-repair mold.)
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“Do you use polymer-modified concrete?” (Resists New Hampshire’s salt and freeze cycles.)
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“What’s your warranty?” (Look for 5+ years on materials/labor.)
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“Can I see local references?” (Check Google My Business and NH BBB.)
Red Flags: No written contract, demands full payment upfront, and vague timelines.
DIY vs. Pro Repair Costs in NH
| Issue | DIY Cost | Pro Cost |
|---|---|---|
| Hairline crack seal | $20 (kit) | $150–$300 |
| Spalling patch | $50 | $800–$1,500 |
| Slab leveling | N/A | $3–$6/sq. Ft. |
| Foundation Repair | N/A | $5K–$15K |
Final Thoughts
New Hampshire concrete faces battles that Arizona or Florida folks can’t fathom. Fixing cracks, spalling, and crawl space water problems quickly can save you money on repairs. When in doubt, get a pro’s eyes on it—most offer free concrete surface deterioration inspections.
Pro Tip: Book a pre-winter concrete checkup every October. Seal gaps, clean gutters, and trim encroaching roots.
About the Author: I have 40 years of experience in New England’s concrete repair service industry. I’ve seen everything—from epoxy garage floors in Kittery to frost-heaved driveways in Conway.
Trust me: New Hampshire’s concrete needs TLC, but it will outlast the Old Man of the Mountain with the right know-how.
Call us for a free estimate, or contact us today through email!
Frequently Asked Questions:
Q: How does hydrostatic pressure from NH’s clay-rich soil affect foundation breaks, and what repair methods are required?
Answer:
Hydrostatic pressure occurs when clay soil full of water expands. This expansion pushes against the foundation walls, leading to horizontal gaps in the basement walls. Carbon fiber straps or wall plate anchors can stop bowing or collapse. PolyLevel foam injections (3,000–5,000 PSI strength) compact soil and lift cement floors and walls. This method tackles the root cause of the problem.
Q: What ASTM standards should NH contractors follow for epoxy damage repairs in freeze-thaw conditions?
Answer:
Epoxy repairs must follow two key standards. First, they need to meet ASTM C881 for bonding strength. Second, they should comply with ASTM C1581 for freeze-thaw resistance. Polymer-modified epoxies with more than 4,000 PSI compressive strength are vital for winter in New Hampshire. They effectively stop rebonding failures. Granite State Epoxy uses vapor-permeable formulations to minimize spalling.
Q: When does spalling indicate substandard air-entrained concrete, and how is it remediated?
Answer:
Spalling, or surface flaking, in New Hampshire driveways often happens due to low air entrainment. This means there should be more than 6% microbubbles, as per ASTM C457. Pro repairs involve:
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Step 1: Remove compromised concrete to a 2″ depth.
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Step 2: Apply a lithium silicate densifier to stabilize the substrate.
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Step 3: Use polymer-modified mortar, like Sakrete Pro-Mix, to patch it. Then, seal it with silane or siloxane.
Q: When does clay soil moisture make helical piers necessary for stabilizing slabs?
Answer:
New Hampshire’s clay soils expand at >30% moisture content, lifting concrete floors >¾”. When the depth is 8 to 12 feet, use galvanized steel helical piers. This is necessary if the soil’s plasticity index (PI) is over 25%, according to ASTM D4318. A1 Foundation Crack Repair uses 3″ diameter piers with a 10K lb load capacity.
Q: How does PolyLevel’s closed-cell foam differ from mud jacking for frost heave repairs?
Answer:
| Factor | PolyLevel | Mudjacking |
|---|---|---|
| 95% closed-cell polyurethane | Cement slurry | |
| 2.5 lb/ft³ (no added soil stress) | 100+ lb/ft³ (risks further sinking) | |
| Impermeable (ASTM D1621) | Absorbs moisture, erodes over time | |
| ±1/16″ accuracy | ±¼” sag accuracy | |
| 15 minutes | 48–72 hours |
PolyLevel’s NSF-certified foam is preferred for New Hampshire’s freeze-thaw cycles.
Our Locations:
Nashua, NH
North Hampton, NH
Concord, NH