What Is Ardex PU 30? Uses, Coverage & Application Guide

Preparing a subfloor properly is essential before installing new flooring, especially where residual moisture may affect the performance of adhesives and levelling compounds. That's where Ardex PU 30 comes in.

Ardex PU 30 is a single-component polyurethane primer that acts as a primer, moisture barrier and substrate consolidator. It's designed to help prepare a wide variety of absorbent and non-absorbent subfloors, making it a versatile solution for both residential and commercial flooring projects.

What Is Ardex PU 30 Used For?

Ardex PU 30 has three main applications:

1. Moisture Barrier

One of its primary uses is as a moisture barrier on cement screeds and concrete floors with elevated residual moisture.

It can be used as a barrier on:

• Cement screeds and concrete floors with up to 6 CM-% (98% RH) residual moisture.
• Cement screeds with underfloor heating up to 3 CM-% (85% RH).

This helps protect subsequent flooring systems where excessive residual moisture is present.

2. Primer

Ardex PU 30 can be used as a primer on both new and existing substrates, including:

• Concrete
• Cement screeds
• Calcium sulphate screeds
• Terrazzo
• Ceramic tiles
• Chipboard
• OSB
• Hardboard
• Dry screed boards
• Existing adhesive residues that are firmly bonded

It also acts as a quick primer beneath Ardex reaction adhesives such as SMP and polyurethane adhesives.

3. Substrate Consolidator

Highly absorbent or weak surface layers can affect the performance of flooring systems.

Ardex PU 30 penetrates the substrate to strengthen and consolidate absorbent surfaces before levelling or bonding takes place, helping create a more stable base for installation.

Key Features

Ardex PU 30 offers a number of practical benefits for flooring professionals:

• Ready to use single-component formula.
• Water- and solvent-free.
• EMICODE EC1 PLUS certified for very low emissions.
• Suitable for underfloor heating.
• Can be used on both absorbent and non-absorbent substrates.
• Reworkable after approximately 1 hour.
• Can be used beneath Ardex reaction adhesives.

Coverage

The amount of product required depends on how Ardex PU 30 is being used.

Application	Coverage
Primer (single coat)	100–150g/m²
Moisture barrier (two coats)	250–300g/m² total

When being used as a moisture barrier, Ardex recommends two cross coats, ensuring a total application rate of approximately 300g/m².

Drying Times

Under normal site conditions (approximately 20°C and 65% relative humidity):

• Walkable after: 40–50 minutes
• Primer coat dry: Approximately 1 hour
• Quartz-coated applications: Approximately 2 hours

Lower temperatures or higher humidity may increase drying times.

How to Apply Ardex PU 30

For the best results:

1. Mechanically prepare the subfloor and remove all dust, grease, oil and contaminants.
2. Shake the container thoroughly before use.
3. Apply using a short-pile velour or foam roller in a thin, even coat.
4. Avoid puddles, as these can slow drying and cause foaming.
5. Apply additional coats where required, depending on the application.

Learn More from Ardex

For more installation tips, product demonstrations and technical guidance, visit the Ardex UK YouTube channel, where you'll find videos covering a wide range of Ardex flooring products and systems.

Final Thoughts

Whether you're dealing with elevated residual moisture, strengthening an absorbent substrate or preparing a floor before applying reaction adhesives, Ardex PU 30 provides a practical all-in-one solution. Its ready-to-use formula, rapid drying time and compatibility with a wide range of substrates make it a valuable addition to any flooring installation.

At Floormart, we stock Ardex PU 30 alongside a wide range of Ardex adhesives and Kelmore subfloor preparation products, helping you complete every stage of your flooring project with confidence.