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Quick, low-risk steps

  1. Stay out of the basement if the wall is bowing or unstable.
  2. Record the crack's location, width, and whether it changes with weather.
  3. Check if water enters through the crack during or after rain.
  4. Look for signs of movement: sticking doors, uneven floors, or new cracks upstairs.
  5. Ask every bidder to state the proposed water source and repair method.

Is the Crack from Water or Movement?

Cracks in basement walls can be caused by water pressure, soil settlement, or foundation movement. A vertical crack that leaks during rain is often a water issue, while a horizontal crack or one that is wider at the top may indicate structural movement. Document the crack with photos and measurements over time to share with professionals.

Water-related cracks may be sealed with epoxy or polyurethane injections from the interior, but this does not address the source of the water. Exterior waterproofing, including excavation and membrane application, may be needed for long-term control. A structural engineer can determine if the crack is a safety concern.

  • Vertical or stair-step cracks often relate to shrinkage or minor settlement.
  • Horizontal cracks can signal soil pressure and require structural evaluation.
  • Cracks wider than 1/8 inch or growing should be assessed by an engineer.
  • Efflorescence (white powder) near a crack suggests water movement.
  • A crack that leaks only after heavy rain may be manageable with drainage improvements.

Questions to Ask Before Repair

Before hiring a contractor, ask how they determined the crack's cause. A reputable professional will explain whether the crack is active or dormant and whether water is involved. They should also discuss the limitations of interior sealants versus exterior excavation.

Request a written scope of work that includes the repair method, materials, and warranty. If the crack is structural, the repair may involve carbon fiber straps, wall anchors, or steel beams. Always verify that the contractor is licensed and insured for the proposed work.

  • What is the proposed water source, and how was it identified?
  • Will the repair be interior, exterior, or both?
  • What materials will be used, and what is their expected lifespan?
  • Does the warranty cover future leaks or movement?
  • Will the repair require a permit or utility location?

Interior vs. Exterior Crack Repair

Interior crack injection is a common method for sealing leaking cracks from inside the basement. It involves injecting epoxy or polyurethane into the crack to fill voids and stop water. This method is less disruptive but does not address exterior water pressure or soil issues.

Exterior repair requires excavation to expose the foundation wall, applying a waterproof membrane, and installing drainage. This approach can address the source of water but is more expensive and disruptive. A contractor should explain why one method is recommended over the other for your specific crack.

  • Interior injection is often faster and less costly but may not prevent future cracking.
  • Exterior waterproofing can relieve hydrostatic pressure but requires digging.
  • Combining interior and exterior methods may be necessary for severe leaks.
  • Ask about the impact on landscaping, walkways, and utilities.
  • Ensure the contractor calls 811 before any excavation.

When to Involve a Structural Engineer

A structural engineer is trained to evaluate whether a crack affects the safety of your home. They can provide an independent assessment and recommend repair options. This is especially important if you plan to sell the home or if the crack is near a corner or beam.

An engineer's report can also help you compare contractor bids by providing a baseline scope of work. Some waterproofing companies have in-house engineers, but an independent evaluation may offer more objective advice. Ask for credentials and a written report.

  • Hire an engineer if the crack is horizontal, growing, or accompanied by bowing.
  • An engineer can specify repair methods like carbon fiber or wall anchors.
  • Get a written report to share with contractors for consistent bids.
  • Ask if the engineer will oversee the repair for quality assurance.
  • Check that the engineer is licensed in Pennsylvania.

Take this with you

Evidence and scope checklist

  • Crack location, width, and pattern documented
  • Evidence of water entry or efflorescence
  • Signs of structural movement elsewhere in the home
  • Proposed water source and repair method stated
  • Interior or exterior approach explained
  • Materials and warranty details provided
  • Permit and utility location requirements addressed
  • Impact on finishes and restoration included
  • Structural engineer report if needed
  • Contractor license and insurance verified
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Common questions

What homeowners ask next

Can I just fill the crack with hydraulic cement?

Hydraulic cement can temporarily stop active leaks but does not address the underlying water source or structural movement. It may fail over time and is not a permanent repair.

How do I know if a crack is structural?

Structural cracks are often horizontal, wider than 1/8 inch, or accompanied by bowing walls, sticking doors, or uneven floors. A structural engineer can provide a definitive assessment.

Will my homeowner's insurance cover crack repair?

Insurance typically does not cover foundation cracks from normal settling or water seepage. Check your policy for specific coverage related to sudden events or structural damage.

Evidence

Sources used for this guide

Research checked July 31, 2026

Optional next step

Need an on-site professional?

Use the guide and worksheet first so you can describe the situation and compare the full scope. A referral is optional; you can also contact a licensed local provider directly.

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We have not enabled a provider route for this site. Use the checklist to contact and verify local providers yourself; urgent hazards should go to the appropriate emergency or public service.