Guide
How to Choose Underlayment for Laminate Flooring
Underlayment supports the flooring system, affects sound and thermal behaviour, and may provide a moisture layer where appropriate. It does not level a badly uneven floor.
Choose laminate underlayment only after checking the subfloor and the flooring collection’s requirements. It separates the planks from the base, influences impact sound and thermal resistance, and may form part of a moisture-control layer. A soft or overly thick product cannot correct a seriously uneven subfloor.
What underlayment is meant to do
- Separate the floating floor from the subfloor and reduce impact transmission.
- Accommodate minor surface features within the limits of the flooring system.
- Support the locking joints by reducing point loading from normal use.
- Contribute to thermal performance in some constructions without replacing a proper insulation design.
Compare the material with the system
Foam rolls, rigid boards, cork and combined products differ in stiffness, durability, moisture behaviour and installation method. The name of a material is not enough: confirm the permitted subfloor, load, thickness and warranty conditions for the exact product.
Underlayment over radiant heating
For radiant floor heating, use underlayment explicitly approved for the heating system and compatible with the laminate. Excess thermal resistance can reduce heat transfer, so the flooring, underlayment and heating instructions need to be read as one system.
What it cannot fix
- Pronounced dips and high spots in the subfloor.
- Flexing timber, weak screed or loose surface layers.
- Leaks, rising damp or a missing waterproofing solution.
- A missing expansion gap or incorrectly assembled locking joints.
How to compare options
Compare the approved base, stiffness, thickness, moisture behaviour, sound rating, heating compatibility and installation requirements. Do not choose solely by maximum thickness or a promise of a warmer floor: an overly soft system can shorten the life of the joints.
Frequently asked questions
Can I install two layers of underlayment?
Only when the flooring system explicitly permits it. Extra layers change stiffness and floor height and may harm the locking joints.
Will underlayment hide an uneven floor?
It can accommodate only minor features within the manufacturer’s limits. Pronounced changes must be corrected in the subfloor.
Do I need an underlayment with a vapour barrier?
That depends on the subfloor and floor build-up. Follow the materials’ instructions instead of adding one automatically.
Which underlayment is best for radiant heating?
Use a product compatible with both the laminate and the heating system and with suitable thermal properties. There is no universal best material.