Using Shingles to Level a Floor: Practical Guide

Leveling a floor is essential for stability, safety, and the long-term performance of flooring materials. While professional methods rely on shims, leveling compounds, or structural adjustments, some DIY projects consider using roof shingles as an improvised leveling aid. This article explains when, why, and how to avoid or properly use shingles in floor leveling, with safer alternatives and best practices for American homes.

Tools And Materials

Before starting, gather the right tools and understanding of what shingles can—or cannot—do in a leveling project. Shingles are not designed as precision leveling materials, but they can serve as temporary packers in limited scenarios.

• Measuring tools: tape measure, level, chalk line
• Cutting tools: utility knife, straightedge
• Shims: plastic or wood, for small adjustments
• Leveling compounds: self-leveling underlayment or latex Portland cement
• Plywood or subfloor underlayment: for added support
• Adhesives and fasteners: floor glue, screws, termite-resistant treated lumber if needed
• Safety gear: gloves, eye protection, dust mask

Key note: Shingles are best avoided as permanent leveling aids due to moisture absorption, degradation, and uneven surfaces. Use them only as a last resort or for temporary shimming while installing proper materials.

Safety Considerations

Floor leveling work can uncover hazards such as uneven joists, rot, or structural issues. Address these first to prevent future problems.

• Identify rot or mold in the subfloor and repair before proceeding.
• Ensure electric and plumbing are de-energized and safely routed.
• Wear protective gear to guard against dust and sharp edges.
• If structural issues exceed simple leveling, consult a licensed contractor.

Shingles themselves pose risks if used improperly. They can trap moisture against the subfloor, invite mold, and compress irregularly, which undermines long-term flatness. Treat shingles as a temporary filler only, and replace with proper subflooring or leveling compounds as soon as feasible.

Step By Step Process: When Shingles Are Considered For Temporary Leveling

In rare cases, homeowners may temporarily need to level small high spots while awaiting materials. The process below emphasizes using shingles cautiously and prioritizing approved leveling methods.

1. Prepare the surface: Remove debris, clean the area, and inspect for protrusions or nails that could damage flooring.
2. Mark high spots: Use a straightedge and level to identify where the floor is out of level by more than 1/4 inch per 6 feet.
3. Temporary shimming (very limited): If a tiny adjustment is needed and you lack proper materials on-site, place flat, thin shingles as temporary shims under a plywood patch, not directly under finished flooring. Do not exceed small thickness changes—no more than necessary to keep the surface from rocking.
4. Apply a permanent solution: Install a proper leveling compound or underlayment according to product instructions. If the floor is wooden subflooring, consider sistering joists or installing a new subfloor for significant deviations.
5. Install underlayment or finish flooring: Once the leveling material cures, lay the final flooring material per manufacturer’s guidelines.

Important: Do not rely on shingles for structural leveling. They should not replace self-leveling underlayment, plywood underlayment, or other approved methods. Use shingles solely as a temporary, minimal filler under supervision of a professional if ever needed.

Common Issues And How To Avoid Them

Using shingles can create several problems if misapplied. Understanding these issues helps keep the project safe and durable.

• Moisture damage: Shingles absorb moisture and can wick it into the subfloor, promoting rot and mold. Avoid long-term exposure; replace with moisture-resistant materials.
• Uneven compression: Shingles compress irregularly, creating new high spots over time. This undermines flatness and leads to squeaks and gaps.
• Subfloor instability: Improper leveling can leave operable gaps that allow movement and creaking. Use proper fasteners and ensure a solid base before final flooring.
• Durability concerns: Roofing shingles are not rated for interior floor loads. Rely on products rated for interior use to ensure longevity.

Mitigation steps include using proper leveling compounds, confirming substrate straightness with a level, and performing a test area before full-scale use of any improvised method.

Alternative Materials And Best Practices

Given the limitations of shingles, consider proven alternatives that deliver consistent, legal, and durable results for floor leveling in American homes.

• Self-leveling underlayment: A cement-based compound that flows to eliminate low spots. Ideal for concrete, plywood, and existing substrates.
• Powdered leveling compounds with water-activated mix: Useful for minor irregularities and can integrate with radiant heat systems if specified.
• Wood shims: Place thin, tapered shims under joists or subfloor areas to address small discrepancies. Use a straightedge and level for verification.
• Plywood or OSB underlayment: Increases rigidity and provides a fresh surface for finishing materials, especially over uneven plywood floors.
• Structural fixes: If large deviations exist, consider sistering joists, adding a new subfloor, or consulting a structural professional.

Best practice is to identify the root cause of floor unevenness—sagging joists, loose subfloor, or moisture damage—and address it before applying any leveling product. This approach ensures long-term stability and minimizes future squeaks or cracks.

Quality Control And Final Checks

After leveling work, confirm that the floor is truly flat and ready for finishing materials. Quality checks prevent costly rework.

• Recheck level: Use a long straightedge and a carpenter’s level along multiple directions.
• Check flatness: Ensure there are no ridges or pits that could telegraph through the final flooring.
• Probe for moisture: If concrete, test moisture content to ensure compatibility with flooring adhesives or finishes.
• Allow curing time: Give leveling products the full cure time before installing final flooring material.
• Inspect for movement: After installation, walk the area to ensure there are no squeaks or loose areas.

Following these steps helps ensure a robust, long-lasting floor that performs well under traffic and furniture load.