Are you noticing problems with the concrete of your new home’s foundation or in your new swimming pool? If so, you’re not alone. Homeowners have recently been noticing a rare issue with concrete. It has been referred to as Concrete Cancer. The technical name for this phenomenon is Near-Surface Alkali-Silica Reaction, or NSASR, which has been found in Central Texas.
What is Concrete Cancer and How is it Identified?
If you see a sticky gel or white powder forming on your concrete slab, driveway, or pool deck built within the last 1-2 years, your concrete might be undergoing a surface-level chemical reaction. Moisture interacts with certain minerals in the concrete, forming a gel that rises to the surface. While it doesn’t cause deep cracking, it creates an unsightly appearance and is difficult to fix.
If you notice any of the following, it may be Concrete Cancer:
- Oozing Gel & White Residue – A sticky, brownish gel forms on the concrete surface and dries into a white, powdery residue.
- Checkered or Patterned Distress – The gel and residue often appear in distinct patterns, especially near grade beams.
- Surface Discoloration – Dark patches or staining may form due to moisture and chemical reactions.
- Flooring Issues (if applicable) – Cracking, pitting, ridging, or debonding of tiles, coatings, or adhesives.
Tactile & Structural Signs of Concrete Cancer
- Hard/Brittle or Soft/Viscous Gel – Fresh exudations feel sticky or viscous, while older gel hardens over time.
- Surface-Only Damage – Unlike traditional ASR, NSASR does not cause deep, structural cracking but remains at the near-surface level.
Steps to Take if You Suspect Concrete Cancer
Acting early can prevent long-term deterioration, flooring failures, and unnecessary repair costs. Reaching out to the original builder, contractor, or concrete supplier is a logical first step, especially if your foundation or pool is relatively new and still under warranty. However, the success of this approach depends on the terms of your warranty and the builder’s willingness to assist. Before approaching the builder, you will want to gather documentation to support your claim. The following steps are the best way to proceed.
- Gather Evidence
- Take photos/videos of the damage, including gel exudations, residue, flooring issues, and moisture presence.
- Keep records of repairs, maintenance, and any relevant contracts/warranties.
- Perform Basic Testing
- pH Test: Use pH strips (ASTM F710 method) to test moisture on the surface—elevated pH (10–12) may indicate NSASR.
- Gel Monitoring: Wipe off the gel and check if it reappears within days.
- Consult a Professional
- Hire a forensic engineer or concrete specialist to conduct in-depth RH (relative humidity) and petrographic analysis (a detailed examination of concrete).
- Request concrete coring for lab testing of ASR gel presence and aggregate composition.
- Contact the Original Builder or Contractor
- Provide a written request detailing the issue, including expert findings and photos.
- Request remediation under the warranty or builder’s responsibility.
- If the contractor is unresponsive or denies responsibility, you should contact a lawyer focused on Construction Law, such as The Law Offices of Cesar A Montalvo, to explore legal options.
- Take Preventative Measures
- Clean the surface regularly – Wipe off gel exudations and white residue to prevent buildup.
- Use a mild alkaline cleaner (avoid acidic cleaners, which can worsen ASR by lowering pH and weakening concrete).
- Improve drainage around the structure to prevent water infiltration.
- Ensure proper vapor barriers are installed under slabs (if missing, remediation may be more difficult).
- Apply moisture control coatings or sealers to limit water movement into the concrete. Lithium silicate sealers can neutralize ASR gel expansion and help stabilize the surface. Lithium-based densifiers are more effective than sodium/potassium-based sealers, which can worsen ASR.
- If patching, use materials containing Class F fly ash or natural pozzolans to reduce pH and limit further ASR reactions.
- If NSASR is damaging flooring adhesives or coatings, switch to moisture-resistant adhesives or breathable flooring systems.
If the Concrete Cancer is severe, causing widespread deterioration or ongoing moisture issues, consider:
- Surface Grinding & Resurfacing – Remove the top layer and reapply a lithium-based treatment.
- Concrete Overlay – If damage is cosmetic, a thin overlay with ASR-resistant material may help.
- Full Slab Replacement – Rare but necessary if structural integrity is compromised (not common with NSASR).
Legal Recourse
We hope you never have to deal with Concrete Cancer, or any construction issue for that matter. But if you do, The Law Offices of Cesar A Montalvo is here to support you on your journey. With experience in Construction Law, we have the expertise to confront contractors and builders who are not willing to remedy the damage they have caused.
