What actually needs to go under vinyl flooring? The honest answer: It mainly depends on whether you're installing click vinyl (floating) or glue-down vinyl (fully adhered). This is because both systems require a completely different substructure. Here's an overview – including a table that will help you decide.
The Most Important Things in Brief
- Click Vinyl: level, dry subfloor + possibly a vapor barrier + impact sound insulation (unless integrated).
- Glue-Down Vinyl: NO underlayment – instead, primer + leveling compound, then adhere directly.
- Always: Subfloor must be clean, dry, and level.
- Vapor Barrier: usually mandatory on mineral subfloors (screed) for click vinyl.
- Integrated Insulation? Then NO additional underlayment.
Table of Contents
- The Answer at a Glance
- Under Click Vinyl (Floating)
- Under Glue-Down Vinyl (Adhered)
- Prerequisite: The Subfloor
- Frequently Asked Questions
- Conclusion
The Answer at a Glance
| Layer | Click Vinyl (Floating) | Glue-Down Vinyl (Adhered) |
|---|---|---|
| Vapor Barrier | yes, on screed/mineral (unless integrated) | not applicable |
| Impact Sound Insulation / Underlayment | yes, unless integrated | no (fixed bond) |
| Primer | no | yes |
| Leveling Compound | for unevenness | almost always |
Under Click Vinyl (Floating)
Click vinyl is not glued but lies freely on the subfloor. Depending on the situation, the following comes underneath:
- Vapor Barrier: On mineral subfloors like screed, residual moisture can rise – a PE vapor barrier film protects the floor. Some underlays have it integrated.
- Impact Sound Insulation / Underlayment: makes the floor quieter and compensates for micro-unevenness. Important: pressure-stable, not too soft, otherwise the click connection will suffer. If your vinyl already has integrated insulation, NO additional underlayment should be used. Details in the guide Impact Sound Insulation under Vinyl – Necessary or Not.
Under Glue-Down Vinyl (Adhered)
Glue-down vinyl is fully adhered – here, no underlayment and no insulation go underneath, but rather a cleanly prepared subfloor. This specifically means:
- Primer: binds dust, regulates absorbency, creates adhesion – see Primer before Glue-Down Vinyl – When it's Mandatory.
- Leveling Compound: makes the surface smooth as glass because every unevenness will show through the thin covering – see Choosing the Right Leveling Compound for Vinyl Flooring.
Prerequisite: The Subfloor
No matter the system – the subfloor must be clean, dry, load-bearing, and level. Before installation, check three things: flatness (with a straightedge), stability (is it sandy or crumbling?), and moisture (especially with fresh screed). Only when the base is right can the flooring system be built upon it. Still unsure whether click or glue-down? Then Click Vinyl or Glue-Down Vinyl? will help you further.
Frequently Asked Questions
What needs to go under click vinyl?
On a level, dry subfloor: if necessary, a vapor barrier (on screed) and pressure-stable impact sound insulation – unless the product already has integrated insulation.
Is a vapor barrier needed under vinyl?
For floating click vinyl on a mineral subfloor (screed), usually yes, to prevent rising residual moisture. Some underlays have the vapor barrier integrated.
What goes under glue-down vinyl?
No underlayment and no insulation – instead, primer and leveling compound for a firm, smooth subfloor. Glue-down vinyl is directly fully adhered.
Does vinyl with integrated insulation need an underlayment?
No. An additional underlayment would make the floor too soft and overstress the click connection. On mineral subfloors, a thin vapor barrier may still be necessary – observe manufacturer's instructions.
Conclusion
What needs to go under vinyl flooring depends on the system: click vinyl may need a vapor barrier and pressure-stable impact sound insulation, while glue-down vinyl needs primer and leveling compound instead of an underlayment. Common to both is a clean, level, dry subfloor. Browse Click Vinyl and Glue-Down Vinyl – or get your free sample in advance.