1. The Role of Limestone in SPC Flooring Quality
SPC flooring consists of a rigid core made from a mix of limestone (calcium carbonate), PVC (polyvinyl chloride), and stabilizers. While limestone adds strength, too much limestone and not enough PVC can lead to a brittle, moisture-absorbing core. Here’s why this matters:
- Higher limestone content makes SPC flooring prone to cracking and breaking under impact.
- Excessively porous cores can absorb moisture, leading to expansion, warping, or weakening of the structure.
- Premium SPC maintains a balanced ratio of PVC and limestone, ensuring flexibility and durability.
When purchasing SPC flooring, homeowners should research the composition and avoid cheaper options with an excessive limestone ratio that sacrifices resilience.
2. The Importance of a Vapor Barrier on the Subfloor
Even though SPC flooring is marketed as 100% waterproof, this only applies to the planks themselves. Moisture from below, especially from concrete subfloors, can cause major failures if not properly managed.
Why a Vapor Barrier is Essential:
- Concrete naturally retains and releases moisture over time. Without a vapor barrier, moisture can seep into the SPC flooring, causing warping and mold growth underneath.
- High humidity levels can lead to click-lock failures as planks expand and push against each other.
- A vapor barrier prevents hydrostatic pressure from forcing moisture upwards into the flooring.
How to Ensure Proper Moisture Protection:
- Perform a moisture test on the subfloor before installation.
- Use a 6-mil plastic vapor barrier or other roll on vapor barriers over concrete to prevent moisture from reaching the flooring.
- Seal any cracks or gaps in the subfloor that could allow moisture penetration.
3. The Critical Need for a Flat Subfloor
SPC flooring is rigid, meaning it does not flex or conform to an uneven surface. An uneven subfloor is one of the leading causes of SPC floor failure.
Problems Caused by an Uneven Subfloor:
- Gaps & Lifted Edges: If the subfloor isn’t level, SPC planks may not lock together properly, causing gaps or lifted edges.
- Click-Lock Failure: The locking mechanisms can break if forced over an uneven surface, leading to loose planks.
- Noisy Floors: Unevenness causes hollow spots, leading to creaking or popping sounds when walking.
How to Prepare the Subfloor Correctly:
- Ensure the floor is level within 3/16” over a 10-foot span.
- Use a self-leveling compound to fix dips and valleys in concrete.
- For wood subfloors, sand down high spots and fill in low areas before installation.
- Always follow the manufacturer’s guidelines for subfloor preparation.
Final Thoughts: How to Avoid SPC Flooring Failures
While SPC flooring offers many benefits, poor material quality, lack of moisture protection, and improper subfloor preparation can lead to premature failures. Here’s how to ensure success:
✔ Choose high-quality SPC flooring with a balanced PVC-to-limestone ratio. ✔ Install a vapor barrier over concrete to prevent moisture-related issues. ✔ Ensure the subfloor is perfectly level before installation. ✔ Follow manufacturer guidelines for installation and maintenance.
By taking these precautions, homeowners can enjoy beautiful, long-lasting SPC flooring without the risk of common failures.