Best Water Underfloor Heating Pipes: PERT vs PERT-AL-PERT

Underfloor heating (UFH) systems require reliable, durable, and efficient piping to distribute warm water effectively. Two of the most common underfloor heating pipe types used for water-based UFH systems are PERT (Polyethylene Raised Temperature) pipes and PERT-AL-PERT (Polyethylene Raised Temperature with Aluminium core) multilayer pipes.

This guide explores their technical performance, durability, heat conductivity, ease of installation, and overall efficiency in residential and commercial applications. The information is sourced from industry reports and expert opinions, with external references to ensure credibility.

1. Understanding PERT and PERT-AL-PERT Pipes

1.1 What is PERT Pipe?

PERT (Polyethylene Raised Temperature) pipes are made from a special type of polyethylene that has been designed to withstand higher temperatures without the need for cross-linking (unlike PEX). PERT pipes are often constructed with an oxygen barrier layer (EVOH – Ethylene Vinyl Alcohol) to prevent oxygen diffusion into the water, which could otherwise lead to corrosion in metal components of the UFH system.

🔗 Differences Between PERT, PERT-AL-PERT, and PERT-EVOH Pipes – The UFH Expert

1.2 What is PERT-AL-PERT Pipe?

PERT-AL-PERT pipes are five-layer composite pipes consisting of an inner and outer PERT layer, adhesive layers, and an aluminum (AL) core. The aluminum core makes the pipe more rigid and helps it retain its shape when bent. The AL layer also serves as a 100% oxygen barrier, preventing any oxygen diffusion into the system.

🔗 PERT-AL-PERT Pipe Specifications – The UFH Company

2. Oxygen Barrier & Corrosion Resistance

2.1 Why an Oxygen Barrier is Important

Oxygen ingress into a water-based UFH system can cause corrosion in metallic components such as manifolds, boilers, and pumps. A proper oxygen barrier prevents rust formation and sludge build-up, maintaining system efficiency.

2.2 Oxygen Barrier in PERT Pipes

PERT pipes with EVOH barriers prevent oxygen diffusion by using a polymer oxygen-blocking layer. The EVOH layer is sandwiched between protective polyethylene layers to ensure longevity.

🔗 200M PERT EVOH 16mm Pipe – Underfloor Heating Express

2.3 Oxygen Barrier in PERT-AL-PERT Pipes

PERT-AL-PERT pipes completely block oxygen ingress due to their aluminum core, making them more effective than EVOH barriers in long-term performance.

🔗 PERT-AL-PERT’s Oxygen Barrier – The UFH Company

3. Heat Conductivity & Energy Efficiency

3.1 PERT Pipe Heat Conductivity

PERT pipes have a thermal conductivity of around 0.40 W/m·K. The smooth inner walls reduce friction, allowing warm water to flow efficiently.

🔗 Comparing UFH Pipes – First Trace Heating

3.2 PERT-AL-PERT Pipe Heat Conductivity

The aluminum layer in PERT-AL-PERT pipes increases thermal conductivity to about 0.45 W/m·K, allowing for slightly faster heat transfer and improved heat distribution.

🔗 Advantages of PERT-AL-PERT in UFH – BuildHub Forum

4. Installation & Handling

4.1 PERT Pipes – Ultra-Flexible

✅ Highly flexible, making installation easy
✅ Great for complex layouts with tight bends
❌ Tends to “spring back”, requiring more fixings

🔗 PERT Pipe Installation Guide – UFH Express

4.2 PERT-AL-PERT Pipes – Form-Stable

✅ Holds its shape when bent, making it easy to lay out
✅ Ideal for single-person installations
❌ Less flexible than PERT, requiring larger bending radii

🔗 PERT-AL-PERT Pipe Handling Tips – The UFH Company

5. Suitability for Different UFH Systems

5.1 Screeded Floors

Both PERT and PERT-AL-PERT are suitable. PERT is preferred for flexibility, while PERT-AL-PERT makes neat layouts easier.

🔗 UFH Pipe Choice for Screeded Systems – ProWarm

5.2 Dry UFH Systems (Spreader Plates, Panels, Joists)

🔹 PERT-AL-PERT is better for dry systems because it holds its shape in spreader plates and grooved panels.

🔗 Using PERT-AL-PERT in Dry UFH – BuildHub Forum

6. Longevity & Durability

6.1 Temperature & Pressure Ratings

• PERT pipes: Typically rated 70°C at 6 bar
• PERT-AL-PERT pipes: Rated 95°C at 10 bar, making them suitable for high-temperature applications

🔗 Temperature Ratings – The UFH Company

6.2 Expansion & Stress Resistance

PERT-AL-PERT pipes expand less than PERT due to their aluminum core, making them more stable under temperature fluctuations.

🔗 Pipe Expansion Factors – BuildHub UFH Guide

7. Cost Comparison

✅ PERT pipes are generally cheaper than PERT-AL-PERT.
✅ PERT-AL-PERT pipes have a higher upfront cost but offer better longevity and form stability.

🔗 PERT vs PERT-AL-PERT Price Comparison – AB Newswire

8. Conclusion – Which Pipe is Best for Your UFH System?

Both PERT and PERT-AL-PERT pipes are excellent choices for water-based underfloor heating. The best choice depends on your specific needs:

👉 If you need high flexibility and cost-effectiveness, choose PERT EVOH Pipes.
👉 If you want superior stability and higher heat transfer, go for PERT-AL-PERT Pipes.

🔗 Learn More: Choosing the Right UFH Pipes – The UFH Company

Which UFH Pipe Do You Prefer? Let us Know! 🚀

💬 Comment Below!