What’s the difference between 3mm and 5mm underlay?

Underlay might seem like a background player, but it plays a big role in how your floor feels, sounds, and lasts—especially when you’ve got kids charging about and dogs making surprise appearances!

 
3mm Underlay: Lightweight and Low-Profile

This is your entry-level option, perfect for:

• Low-traffic rooms like spare bedrooms or studies
• Even subfloors with minimal imperfections
• When you need to keep the floor height low

It provides basic cushioning and sound reduction, and is a budget-friendly way to protect your flooring investment.

 
5mm Underlay: Added Comfort and Soundproofing

Thicker and more luxurious, 5mm underlay is ideal for:

• Busy areas like living rooms, hallways, or upstairs bedrooms
• Homes with kids and pets—it absorbs sound brilliantly
• Giving a softer feel underfoot, especially with laminate or engineered wood

I used 5mm in our upstairs rooms, and it’s made a world of difference—quieter steps, comfier floors, and it’s stood up beautifully to toy cars and midnight snack runs!

 
In a nutshell:

• 3mm = Budget-friendly, light cushioning
• 5mm = Extra comfort, better soundproofing

If you're deciding between the two, think about how the room is used and how much traffic it gets. I’m always happy to help if you need advice tailored to your home.