Laminate flooring is a popular choice for many homes and offices thanks to its affordability, durability, and wide range of styles. A key question that often comes up when planning a laminate installation is whether underlay is necessary. The short answer is: in most cases, yes, underlay is recommended. But there are nuances depending on the room, the subfloor, and the specific product you’re using. This blog will walk you through the role of underlay, the benefits, and practical tips to get a professional-looking finish with your laminate flooring.
What is Laminate Flooring Underlay and Why is it Useful?
Laminate flooring underlay is a thin material placed between the subfloor and the laminate planks. It serves several important functions:
- Noise reduction: Underlay helps dampen footfall and other noises, which is especially beneficial in multi-storey homes or rooms with hard surfaces.
- Cushion and comfort: A layer of underlay adds a little spring and makes the floor feel more comfortable underfoot.
- Moisture protection: Some underlays have moisture barriers that help prevent damp from seeping up (particularly important on concrete subfloors).
- Thermal insulation: Underlay can offer a small degree of insulation, helping to keep rooms warmer in winter.
- Stability and flatness: It can help smooth out minor irregularities in the subfloor and provide a more stable base for laminate planks.
When is Underlay Essential?
- Concrete subfloors: A quality underlay with a moisture barrier is highly recommended to protect against damp and to improve comfort and acoustics.
- Timber subfloors: Underlay helps with sound reduction and provides a smooth, stable surface. If the timber subfloor has a lot of irregularities, underlay can help compensate.
- Rooms with high noise sensitivity: In flats, apartments, or rooms directly above living spaces, underlay can significantly cut down impact noise.
- Radiant heat: If you plan to use underfloor heating or radiant heat, choose an underlay specifically rated for use with underfloor heating and follow the manufacturer’s guidelines.
There are exceptions where you might not need underlay:
- If your laminate flooring is a click-lock system with an integrated backing or an acoustic variant that includes a built-in underlay, you may not require an additional layer.
- If the product specification explicitly says no underlay is needed for your chosen laminate, you should follow that guidance.
Types of Underlay and What to Choose
Not all underlays are the same. Here are common types and their intended benefits:
- Polyethylene foam underlay: The most common type, good all-round performance, moisture barrier options are available.
- Vapour barrier underlay: Features a built-in vapour barrier to reduce moisture transmission, suitable for concrete subfloors.
- Acoustic underlay: Designed to reduce sound transmission, useful in multi-storey buildings and apartments.
- Insulating underlay: Provides extra thermal insulation while smoothing minor subfloor irregularities.
- Bamboo, felt, or recycled fibre underlays: Eco-friendly options with varying levels of sound and comfort.
When selecting underlay, consider:
- Subfloor type (concrete vs timber)
- Presence of moisture or damp issues
- Whether you have underfloor heating
- The thickness of the laminate and the recommended underlay thickness by the manufacturer
- Any warranties or guarantees from the laminate manufacturer, as using the wrong underlay can affect coverage
How to Install Laminate Flooring with Underlay
- Prepare the subfloor: Ensure it is clean, dry, and level. Fix any major defects, and remove debris.
- Lay the underlay: Roll out or unroll the underlay across the room, ensuring it covers the entire floor area. Butt joints or seam according to the product instructions, typically with a small overlap or tape.
- Create a gap for expansion: Leave a small expansion gap around the edges of the room (usually about 10–15 mm) to accommodate movement.
- Install the laminate: Start laying the laminate planks following the manufacturer’s instructions, usually staggering joints for a natural look. Use spacers to maintain the expansion gap at walls.
- Accommodate door thresholds and transitions: Use appropriate reducer strips or thresholds to cover expansion gaps where the laminate meets other flooring types.
If you’re using radiant heat, you’ll also want to follow the underlay manufacturer’s guidelines for heat compatibility, as some underlays are not suitable for use with underfloor heating.
Common Pitfalls to Avoid
- Skimping on underlay: Skipping underlay can lead to louder footsteps, a less comfortable surface, and potential moisture issues.
- Ignoring moisture considerations: Concrete subfloors can transmit moisture, and without a moisture barrier, you risk laminate deforming or cupping over time.
- Not following manufacturer guidance: Different laminate products have different requirements regarding underlay; always check the installation manual and warranty conditions.
- Overlapping seams: When laying underlay, make sure seams are properly sealed or taped to prevent dirt and moisture from collecting.
Final Thoughts
Laminate flooring generally benefits from the addition of underlay, delivering improved comfort, reduced noise, and added protection against moisture and uneven subfloors. While there are scenarios where you can proceed without underlay, it’s usually safer and more cost-effective in the long run to use the appropriate underlay recommended for your laminate flooring. By choosing the right type of underlay, preparing the subfloor properly, and following the installation guidelines, you can enjoy a durable, attractive floor that stands up to daily life. If in doubt, consult the laminate manufacturer’s recommendations or seek advice from a professional installer to ensure you get the best possible result for your space.