When it comes to laminate flooring, most people focus on the surface—the wood-like finish, the color, or the texture—but often overlook the subfloor beneath. Yet, the subfloor is the unsung hero of a long-lasting laminate floor. It’s the foundation that supports every plank, absorbs foot traffic, and keeps your flooring from shifting, creaking, or warping over time. Choosing the right subfloor isn’t just a technical detail—it can make the difference between a floor that looks flawless for years and one that gives you headaches from day one.
The ideal subfloor provides stability, resists moisture, and pairs seamlessly with your laminate’s locking system. Whether you’re working over concrete, plywood, or an existing floor, understanding which subfloor works best—and why—will save you time, money, and frustration. In the following sections, I’ll break down the top subfloor options for laminate flooring, their pros and cons, and key factors to consider to ensure your flooring installation stands the test of time.
Types of Subfloor for Laminate Flooring
Plywood Subfloor
Plywood is widely considered one of the best subfloors for laminate flooring. It is strong, durable, and provides a stable base that minimizes movement underfoot. Most laminate manufacturers recommend a minimum of ¾-inch plywood to ensure the floor remains firm and avoids gaps or buckling. Plywood also resists expansion and contraction better than particleboard, making it ideal for areas with fluctuating temperatures or humidity. Its smooth surface allows laminate planks to click together easily, ensuring a seamless, professional-looking installation.
Oriented Strand Board (OSB)
OSB is a popular, budget-friendly alternative to plywood. Made by compressing wood strands with adhesives, OSB offers solid support for laminate floors. While slightly rougher than plywood, it can be sanded or leveled to create a smooth surface for installation. OSB is stable and durable, but it is less moisture-resistant than plywood, so extra precautions like a vapor barrier or sealant are recommended in basements or areas prone to dampness.
Concrete Subfloor
Concrete is a highly stable and long-lasting subfloor option, particularly for ground-level installations or basements. Its rigidity prevents laminate from flexing or squeaking, and it works well with radiant heating systems. However, concrete must be completely dry and level before installation. Moisture barriers are essential to protect the laminate from potential water damage, and expansion gaps must be carefully maintained since concrete does not flex like wood.
Existing Vinyl or Tile
In some cases, laminate flooring can be installed directly over existing vinyl or tile, saving the hassle of demolition. The key requirement is a flat, smooth surface free of loose or damaged sections. Any uneven spots can cause the laminate to flex or click apart over time. Installing a quality underlayment over vinyl or tile helps reduce noise, adds cushioning, and creates a better locking surface for the laminate planks. This method can be a cost-effective solution if done with attention to detail.
Factors to Consider When Choosing a Subfloor
Levelness
One of the most important factors for a successful laminate installation is a level subfloor. Even slight unevenness can cause planks to flex, gaps to form, or the locking system to fail. For best results, the subfloor should be level to within 3/16 of an inch over 10 feet. Use a long level or straightedge to check for high or low spots, and apply a leveling compound to correct any imperfections. A perfectly flat subfloor ensures your laminate lies smooth and stable, preventing long-term issues.
Moisture Resistance
Laminate flooring is sensitive to water, so moisture resistance in your subfloor is critical. Wood-based subfloors like plywood or OSB must be kept dry, while concrete subfloors require a vapor barrier to prevent moisture from seeping up into the laminate. Areas like basements, kitchens, or bathrooms are especially prone to moisture problems, so choosing the right subfloor and applying proper moisture protection will significantly extend the life of your flooring.
Thickness and Stability
The thickness of your subfloor directly impacts how sturdy your laminate feels underfoot. Thicker subfloors, such as ¾-inch plywood or OSB, provide a firm base that reduces bounce or flex in the planks. A subfloor that is too thin can lead to squeaking, plank movement, and faster wear. Stability is key—not just for comfort, but to protect the locking mechanism and maintain a long-lasting, professional-looking floor.
Sound and Cushioning
Subfloors can also affect noise levels and how the floor feels when walking. Hard surfaces like concrete transmit more sound, while wood-based subfloors absorb some impact. Pairing the subfloor with a quality underlayment can reduce squeaks, add cushioning, and improve overall comfort. Foam, cork, and rubber underlayments each offer different benefits dependin
Moisture Testing Methods for Laminate Flooring Subfloors
Moisture is the silent enemy of laminate flooring. Even a small amount of water trapped in the subfloor can lead to warping, swelling, buckling, or mold growth. Testing your subfloor for moisture before installation is crucial, whether it’s plywood, OSB, or concrete. Different subfloors require different testing methods to ensure your laminate has a stable, dry foundation.
Testing Plywood and OSB Subfloors
Wood-based subfloors like plywood and OSB must be dry before installation. The recommended moisture content for laminate installation is usually below 12%. Here’s how to test:
- Pin Moisture Meter: This device measures the moisture content by inserting pins into the wood. It gives an accurate reading at different depths. Take readings from multiple spots to ensure consistency.
- Pinless Moisture Meter: These meters use electromagnetic signals to detect moisture without penetrating the wood. They are fast and non-destructive, though less precise in thick plywood or OSB panels.
- Visual and Physical Checks: Look for signs of water damage like discoloration, swelling, or soft spots. Press on the subfloor to check for softness, which may indicate excess moisture.
If moisture readings are too high, delay installation and allow the subfloor to dry completely. Using a dehumidifier or increasing ventilation can speed up the drying process.
Testing Concrete Subfloors
Concrete is particularly prone to moisture issues, especially in basements or ground-level installations. Unlike wood, concrete retains moisture for a long time, so testing is critical. Common methods include:
- Plastic Sheet Test: Tape a 2×2-foot plastic sheet to the concrete surface, sealing all edges. Leave it for 24–48 hours. If condensation forms underneath, moisture is present, and the floor is not ready for laminate.
- Moisture Meter: Pinless meters designed for concrete can give a quick reading, but for precise results, combine with a plastic sheet test.
- Calcium Chloride Test: This is a more advanced test used by professionals. It measures the actual moisture vapor emitted from the concrete over a 24-hour period.
For laminate flooring, the subfloor should typically have a moisture reading below 3% for concrete, or follow the manufacturer’s guidelines. A vapor barrier or moisture-resistant underlayment is essential if readings are borderline or if the installation is in a basement.
Vinyl or Tile Subfloors
Even though vinyl or tile is generally resistant to moisture, trapped water beneath or uneven adhesion can cause problems. Check for signs of:
- Loose or bubbling vinyl
- Cracked or missing grout in tiles
- Dampness under vinyl
A quick visual inspection and moisture meter reading can help ensure the surface is suitable for laminate installation
Subfloor Cost and Material Comparison
Choosing the right subfloor for your laminate flooring is about more than stability—it also affects budget, installation ease, and long-term performance. Different subfloor materials come with varying costs, durability, and suitability for specific rooms. Here’s a breakdown to help you make an informed decision:
Plywood Subfloor
Cost: $2–$5 per square foot (depending on thickness and grade)
Plywood is strong, stable, and widely recommended for laminate flooring. It provides a flat surface that supports click-lock, tongue-and-groove, or glue-down laminate systems. Installation is straightforward, and it performs well in most rooms, including bedrooms, living rooms, and kitchens. Plywood also has excellent resistance to movement, which reduces the risk of squeaks or gaps over time. Its main drawback is cost, as it is generally more expensive than OSB.
OSB (Oriented Strand Board) Subfloor
Cost: $1–$3 per square foot
OSB is an affordable alternative to plywood and offers solid support for laminate. It works best with click-lock floating systems and can be used in most living spaces with proper leveling and moisture protection. While OSB is less expensive, it is slightly rougher and more sensitive to moisture than plywood, so areas like bathrooms or basements require extra precautions.
Concrete Subfloor
Cost: $3–$6 per square foot for finishing/prep (base concrete usually already exists)
Concrete is highly durable and stable, making it ideal for basements, ground-level floors, or areas prone to moisture. Both click-lock floating and glue-down laminate systems work well on concrete, but additional preparation—like leveling, moisture testing, and underlayment—is necessary. While the base concrete may already be present, finishing costs can add up, especially if self-leveling compounds or vapor barriers are required.
Existing Vinyl or Tile
Cost: $0–$2 per square foot (assuming the floor is already in place)
Installing laminate over vinyl or tile can save demolition costs and time. Click-lock floating systems are ideal in this scenario. Costs are minimal if the existing floor is in good condition, but extra leveling or underlayment may be required to ensure a smooth installation. This option is convenient for quick renovations but less suitable for high-moisture or high-traffic areas.
Quick Comparison Table
| Subfloor Type | Approx. Cost per sq. ft | Suitability | Best Laminate System | Key Advantages | Potential Drawbacks |
|---|---|---|---|---|---|
| Plywood | $2–$5 | Most rooms | Click-lock, tongue-and-groove, glue-down | Stable, strong, reliable | Higher cost than OSB |
| OSB | $1–$3 | Living rooms, bedrooms | Click-lock floating | Affordable, strong | Rougher, moisture-sensitive |
| Concrete | $3–$6 (prep only) | Basements, ground floors | Click-lock floating, glue-down | Very stable, durable, moisture-resistant | Prep intensive, costly if leveling needed |
| Vinyl/Tile | $0–$2 (if existing) | Renovation projects | Click-lock floating | Saves demolition, convenient | May need leveling, not ideal for high moisture |
Preparation of Each Subfloor Type
Preparing Plywood Subfloors
Plywood is one of the most reliable subfloors for laminate flooring. Begin by cleaning the surface thoroughly and removing any dust, debris, or protruding nails. Check for uneven spots using a straightedge or level; fill low areas with a leveling compound and sand down high spots. Ensure panels are securely fastened to prevent squeaks. Plywood works best with floating click-lock systems because the stability and flatness allow the planks to snap together securely without adhesive. Tongue-and-groove systems with glue can also work over plywood for a more permanent installation, but floating systems are generally preferred.
Preparing OSB Subfloors
OSB is a budget-friendly alternative that offers good structural support, but it is slightly rougher than plywood. Clean the subfloor thoroughly, sand any rough areas, and fill gaps or depressions with leveling compound. Secure all panels to avoid movement. Click-lock laminate works well over OSB if the surface is smooth and level. Glue-down or tongue-and-groove systems are less common but possible if the OSB is sealed and moisture protection is applied. OSB is best for floating systems rather than glue-down installations because slight expansion and contraction may interfere with glued joints over time.
Preparing Concrete Subfloors
Concrete is ideal for basements or ground-level floors, but it needs careful prep. Clean the surface, remove dust and debris, and check for low or high spots. Use a self-leveling compound to correct imperfections, and perform a moisture test to ensure dryness. Apply a vapor barrier or moisture-resistant underlayment to protect the laminate. Both click-lock floating systems and glue-down laminates can be used over concrete. Floating click-lock systems are easier for DIY installations, while glue-down systems provide maximum stability on flat concrete surfaces. Tongue-and-groove with glue is usually preferred in commercial applications where extra stability is required.
Preparing Existing Vinyl or Tile
Laminate can be installed over smooth, flat vinyl or tile, saving the need to remove the old floor. Clean thoroughly, repair any loose or damaged sections, and level grout lines or uneven areas with a leveling compound. A high-quality underlayment helps with cushioning and noise reduction. Click-lock floating systems are ideal for vinyl or tile because they allow the laminate to move slightly with temperature changes without damaging the old flooring. Glue-down or tongue-and-groove systems can work but are generally not recommended over vinyl, as they may not bond properly or may trap moisture.
Underlayment Considerations
Underlayment is a critical component of any laminate flooring system. It acts as a buffer between the subfloor and the laminate, providing moisture protection, sound reduction, cushioning, and stability. Choosing the right underlayment depends on both the type of subfloor and the laminate installation system you’re using—click-lock floating, glue-down, or tongue-and-groove.
Plywood Subfloors
Plywood subfloors are already strong and stable, so the primary role of the underlayment here is sound absorption and minor leveling. Foam or felt underlayments are ideal for plywood. They reduce footstep noise and make the floor feel more comfortable underfoot without interfering with the locking mechanism of click-lock laminate. For rooms prone to humidity, a thin vapor barrier underlayment can be added to protect the laminate from occasional moisture, especially near kitchens or bathrooms.
OSB Subfloors
OSB subfloors benefit from slightly thicker underlayments because their rougher texture can transmit minor imperfections to the laminate surface. Cork or high-density foam underlayment works well, smoothing out minor bumps while adding sound dampening. OSB is slightly more susceptible to moisture than plywood, so in areas with higher humidity, using a combined foam-vapor barrier underlayment is recommended to protect floating click-lock systems from warping or squeaking. Glue-down systems over OSB usually require a smoother subfloor and minimal underlayment to ensure proper adhesion.
Concrete Subfloors
Concrete subfloors require the most careful underlayment choice due to moisture concerns. A vapor-retardant underlayment is essential to prevent water from seeping up into the laminate and causing swelling or mold. High-density foam, cork, or rubber underlayments with moisture barriers are ideal. For click-lock floating systems over concrete, a thicker underlayment (3mm–5mm) adds cushioning and sound absorption. Glue-down laminates on concrete may require minimal underlayment to maintain strong adhesion, so many manufacturers recommend using a thin moisture barrier or specialized adhesive underlayment designed for concrete.
Existing Vinyl or Tile
When installing laminate over vinyl or tile, the underlayment serves multiple purposes: smoothing minor imperfections, cushioning the floor, and reducing noise. Foam or cork underlayments are ideal for this setup. Vinyl and tile can have uneven grout lines or minor surface irregularities, and a slightly thicker underlayment compensates for these, ensuring a smooth click-lock installation. Glue-down systems are rarely recommended over vinyl because adhesive may not bond well, and moisture can become trapped, so a floating system with quality underlayment is the safest choice.
Specialty Considerations
Some underlayments offer additional features, such as built-in moisture barriers, soundproofing, or thermal insulation. These are particularly useful in basements, apartments, or multi-story homes. When choosing an underlayment, always consider the subfloor type, room conditions (humidity, traffic, sound), and the laminate system to ensure compatibility and long-term durability.
