Plasticizer Migration in Flooring – Causes, Prevention & Solutions

What Is Plasticizer Migration?

Plasticizers are chemical additives used in flexible PVC (vinyl) products to make them soft, flexible, and easier to install. Over time, however, these plasticizers can move—or migrate—from one material into another.

When migration happens, you may see:

• Staining or discolouration of flooring (yellow, brown, or greasy patches)

• Weakening of adhesives and loss of bond strength

• Sticky or oily surfaces at the flooring edge or underside

• Premature failure of vinyl or LVT installations
  
  

This migration is most often seen where vinyl flooring (such as sheet vinyl, LVT, or safety flooring) meets incompatible adhesives, underlays, mats, or finishes.

Common Scenarios in Flooring

1. Vinyl Over Bitumen Adhesives

Old bitumen-based residues are a classic culprit. If new vinyl or LVT is laid directly over them, plasticizers migrate into the bitumen, softening it and causing staining and bond failure.

2. Incompatible Adhesives

Not all adhesives are designed for use with PVC flooring. Solvent-based and cheaper products can accelerate plasticizer migration, leaving flooring unstable.

3. Vinyl and Rubber Contact

When vinyl comes into direct contact with rubber skirting, coving, or rubber-backed entrance mats, staining is common. These mats often leave permanent yellow or brown marks on LVT or sheet vinyl.

4. Improper Underlays or Damp-Proof Membranes

Some foams, underlays, or membranes contain chemicals that react badly with vinyl. Without the right separation layers, migration and staining become inevitable.

How to Prevent Plasticizer Migration

✅ Use the Correct Adhesive System

• Choose adhesives recommended by the flooring manufacturer.

• Acrylic and two-part reactive adhesives are usually safest.

• Avoid solvent-based adhesives unless explicitly approved.
  
  

✅ Prepare Subfloors Thoroughly

• Mechanically remove old adhesive residues such as bitumen or asphalt.

• If removal isn’t possible, isolate residues with a professional-grade smoothing compound.

• Never install vinyl directly onto contaminated surfaces.
  
  

✅ Isolate Incompatible Materials

• Install barrier layers between vinyl and rubber products (skirting, coving, or mats).

• Use separation membranes or primers when subfloors contain problematic residues.
  
  

✅ Control Moisture Levels

• Moisture accelerates migration and adhesive breakdown.

• Test subfloor RH (relative humidity) before installation.

• Apply an epoxy DPM if readings are above manufacturer limits.
  
  

✅ Invest in Quality Materials

• Premium LVT and vinyl use more stable, modern plasticizers with reduced migration risk.

• Pair them with adhesives tested for migration resistance.
  
  

What to Do If Migration Has Already Happened

• Staining from Mats or Rubber: Replace mats with PVC-compatible entrance systems and use barrier films to protect flooring. Some stains are permanent, requiring replacement.

• Adhesive Breakdown: Often, the only solution is uplifting, correcting the subfloor, and reinstalling with a migration-resistant system.

• Commercial Sites: Regular inspections in hospitals, schools, and retail environments can catch early signs of migration before damage spreads.
  
  

Final Thoughts

Plasticizer migration is one of those hidden flooring issues that only shows up months or years later—but by then, the damage is done. With proper subfloor prep, adhesive selection, and protection from incompatible mats or rubber products, you can deliver flooring installations that remain stable and stain-free for years to come.

At Caine Flooring, we only use adhesives and installation methods that are proven to resist plasticizer migration. That means our vinyl flooring and LVT flooring installations across Birmingham and the West Midlands not only look beautiful on day one but stand the test of time.