To properly lay hardwood floors on an uneven surface, the floor itself must be smoothed out before installation begins.
Installing beautiful hardwood flooring requires a stable and level subfloor. Attempting to install hardwood directly onto an uneven surface can lead to squeaks, gaps, and structural issues over time. Therefore, correcting the subfloor is a critical first step.
Preparing the Uneven Subfloor for Hardwood
The process of smoothing out an uneven floor depends largely on the type of subfloor and the degree of unevenness. The goal is to create a flat plane for the hardwood to sit upon.
According to the provided reference, this preparation can be achieved through several methods:
Methods for Smoothing the Subfloor
- Underlays: Specific underlayment materials can help minor imperfections. While some underlays primarily provide moisture protection or sound dampening, others, like leveling compounds applied before the underlay, or thicker underlays designed for minor leveling, can contribute to a smoother surface.
- Re-surfacing: This is a broader term that can involve various techniques to alter the surface of the subfloor. This might include:
- Applying Leveling Compounds: Self-leveling or patch compounds can fill dips and low spots in plywood or concrete subfloors.
- Sanding High Spots: High areas, especially on concrete or wood, can often be reduced by sanding.
- Installing a New Subfloor Layer: In cases of significant unevenness or damage, installing a new layer of plywood or other suitable material over the existing subfloor can create a fresh, flat base.
- Specific to Concrete Surfaces: For concrete subfloors that are uneven, sanding and polishing may be required. Sanding can help reduce high spots, while polishing (often done after leveling compounds are applied and cured) can create a smooth finish suitable for direct adhesion or floating floor installation.
Why is Smoothing Essential?
Hardwood flooring, whether solid or engineered, requires a flat surface to lay correctly. Unevenness can cause:
- Gaps between boards.
- Cupping or warping of the wood.
- Loose boards or movement.
- Excessive wear in high spots.
- Difficulty during installation.
Practical Steps & Considerations
- Assess the Unevenness: Use a long straight edge or a level to identify high and low spots across the entire subfloor. Mark these areas.
- Choose the Right Method: Select the appropriate repair method based on the subfloor type (wood, concrete) and the severity of the unevenness (minor dips vs. significant slopes).
- Clean the Subfloor: Ensure the subfloor is clean, dry, and free of debris before starting any smoothing work.
- Apply Solutions: Implement the chosen method, whether it's applying leveling compound, sanding, or laying a new subfloor layer.
- Verify Flatness: After the smoothing work is complete and cured (if using compounds), re-check the subfloor with a straight edge to ensure it meets the flatness requirements specified by the hardwood flooring manufacturer.
Proper subfloor preparation is the most crucial step to ensure a long-lasting, beautiful, and stable hardwood floor installation on an initially uneven surface.
