Yes, underlayment is strongly recommended when installing laminate over concrete. While it may seem like an extra step, it plays a critical role in protecting your floor from moisture, improving comfort, and protecting your floor.
Why It Matters on Concrete
Concrete subfloors are hard, cold, and porous. Even if they feel dry, moisture vapor can and wick it's way up and affect your laminate floor. Skipping underlayment or using the wrong kind can lead to long-term damage like mold, mildew, warping, or a hollow feel underfoot.
What Underlayment Really Does:
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Moisture Barrier:
Concrete naturally emits moisture vapor, even when it appears dry. Underlayments with built-in vapor barriers protect laminate planks from swelling, mold, or warping.
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Soundproofing:
Laminate can sound hollow or “clicky” when installed directly on concrete. The right underlay can absorb sound making your flooring quieter. -
Comfort:
Concrete is hard and unforgiving. A foam underlay adds a slight cushion, making laminate floors on concrete more comfortable to walk on. -
Insulation:
Some underlays provide minor thermal insulation and can reduce some of the cold from the concrete.
Why Not All Underlayment's Are Equal
Foam underlayments are commonly sold with laminate flooring. The most common are designed for wood subfloors and don’t offer any real moisture protection. In basements or on concrete slabs, choose an underlayment that’s rated for moisture and has vapor-blocking properties.
Summary
An underlayment is more than an accessory, it’s a critical layer that protects your floor. However when it comes to concrete subfloors, basic foam underlays often offer little moisture protection. If installed directly on concrete, they can trap moisture underneath, increasing the risk of mold and mildew.
All-In-One Subfloor was specifically designed to solve these issues. It combines built-in moisture barrier, thermal insulation, and double sided air gap that allows your flooring to breathe. This helps prevent moisture buildup and mold and mildew damage.