What’s the difference between underlay types for wood flooring?
3mm Underlay
This is a lovely lightweight option—ideal if your subfloor is already in good condition and you just need a bit of cushioning and sound insulation. It's often used with engineered or laminate floors and is super budget-friendly. Great for upstairs rooms where you want to soften footsteps (or the sound of jumping four-year-olds!).
5mm Underlay
A little thicker than the 3mm, this gives you extra soundproofing and comfort underfoot. Perfect for high-traffic rooms like living rooms or hallways. I used this in our upstairs landing because the kids race around like it’s a racetrack—it’s been brilliant for muffling the chaos.
Techno Matt Boards
These are rigid board-style underlays, which help level out slight imperfections in the subfloor. They also offer solid support and moisture resistance. I always recommend these if you’re fitting over an older floor or in a home where things might not be perfectly level (been there, done that in our Victorian semi!). They can make your final floor feel smoother and more stable.
Underfloor Heating Underlay
This one’s a must if you’ve got underfloor heating! These underlays are specially designed to conduct heat efficiently, so you get the full benefit of your heating system. Standard underlay can block heat, but underfloor heating underlays are thin and dense to let the warmth through—perfect for those chilly winter mornings in the kitchen.
Quick Tip!
Always check the manufacturer’s guidance for your flooring. Some underlays are better suited to click systems, others to glue-down floors. And if you’re ever unsure, we’re just a call or click away!
In summary:
3mm – Light, basic cushioning.
5mm – Thicker, great soundproofing.
Techno Matt boards – Rigid and stable, perfect for uneven floors.
Underfloor heating underlay – Thin and heat-conductive, ideal for warm toes in winter!
I hope that clears things up! If you’re picking underlay for a specific room, we're happy to help you choose the right one.
