How to Install Underlayment for Kitchen Flooring
Underlayment is the invisible layer that makes your floor feel solid instead of hollow, warm instead of cold, and quiet instead of clacky. It also protects against moisture—critical in kitchens where spills happen. The right underlayment, properly installed, extends the life of your floor and makes it more comfortable to walk on.
Quick Summary
Time needed
2-3 hours
Cost
$100-400
Difficulty
Easy
Choosing the Right Underlayment
Not all underlayment is created equal. What you need depends on your flooring type, subfloor material, and whether moisture is a concern.
For Luxury Vinyl Plank (LVP)
Check if your LVP has attached padding first. If not, use foam or cork underlayment with built-in moisture barrier.
Recommended Options:
- •2-3mm foam with vapor barrier ($0.60-1.00/ sq ft) - Standard choice, good for wood subfloors
- •Cork underlayment ($1.00-2.00/sq ft) - Premium option with superior sound dampening
- •Combination foam/cork ($0.80-1.50/sq ft) - Best of both worlds
For Tile Flooring
Tile needs a rigid, stable base. Foam underlayment will cause tiles to crack. Use cement board or uncoupling membranes.
Recommended Options:
- •1/2" cement backer board ($0.75-1.25/sq ft) - Traditional choice, very stable
- •Uncoupling membrane (Schluter DITRA)($2.00-3.50/sq ft) - Prevents cracks, easier to install
- •1/4" cement board ($0.60-1.00/sq ft) - Thinner option when height is critical
Important: Never use foam or felt underlayment under tile. The flexibility will cause tiles and grout to crack. Tile requires a completely rigid substrate.
For Engineered Hardwood
Floating engineered hardwood needs cushioning and moisture protection. Glue-down or nail-down installations typically don't need underlayment.
For Floating Installation:
- • 2-3mm foam with moisture barrier ($0.50-1.00/sq ft)
- • Cork underlayment for better sound control ($1.00-2.00/sq ft)
- • Manufacturer-specific underlayment (check warranty requirements)
Step-by-Step Installation Guide
1. Clean the Subfloor Thoroughly
Even tiny debris will create bumps that telegraph through your underlayment and flooring. Be obsessive about this step.
- Sweep the entire floor
- Vacuum with a shop vac, including corners and edges
- Check for and remove any protruding nails or screws
- Wipe down with a damp cloth if needed
- Let subfloor dry completely before proceeding
2. Install Moisture Barrier (If Needed)
Over concrete subfloors or in moisture-prone areas, install a separate moisture barrier before underlayment.
When You Need a Moisture Barrier:
- • Installing over concrete (always)
- • Kitchen on slab foundation
- • Basement kitchen
- • Area prone to moisture or humidity
- • Flooring manufacturer requires it
How to Install: Roll out 6-mil polyethylene plastic sheeting. Overlap seams by 8 inches. Tape all seams with moisture barrier tape. Run plastic 2-3 inches up the walls, and trim after flooring is installed.
3. Plan Your Underlayment Layout
Don't just start rolling. Take a minute to plan your layout for the most efficient installation.
Layout Guidelines:
- 1.Roll underlayment perpendicular to your flooring direction
- 2.Start along the longest straight wall
- 3.Plan so seams don't fall under cabinet openings or high-traffic areas
- 4.Minimize waste by measuring and planning cuts first
4. Roll Out and Cut Underlayment
Unroll your first row, making sure it lays flat without wrinkles or bubbles. Cut to fit using a utility knife.
Installation Technique:
- 1.Unroll the first row along your starting wall, leaving a 1/4" gap at the wall
- 2.Cut to length using a utility knife and straightedge
- 3.Smooth out any wrinkles or air bubbles by hand
- 4.Butt the next row tightly against the first—no gaps, no overlaps
- 5.Continue across the room, cutting the final row to fit
5. Tape All Seams
This is critical. Unsealed seams allow the underlayment to shift during flooring installation, creating gaps and uneven spots.
Taping Best Practices:
- • Use underlayment tape specifically designed for the purpose
- • Tape every seam from end to end—don't skip sections
- • Press tape down firmly to ensure good adhesion
- • If underlayment has a moisture barrier, use moisture barrier tape
- • Tape within 30 minutes of rolling out (before it shifts)
Pro Tip: Some underlayment comes with self-adhesive strips along the edges. These make sealing seams faster and easier—just peel and stick to the adjacent row.
6. Cut Around Obstacles
You'll need to cut around cabinet toe kicks, islands, door jambs, and other obstacles. Take your time with these cuts.
Cutting Techniques:
- •For straight cuts: Use a utility knife with a fresh blade and a straightedge
- •For curves and irregular shapes: Make a cardboard template first, then trace and cut
- •Around door jambs: Slide underlayment under the jamb (if undercut) or cut precisely to fit
- •At walls: Leave 1/4" gap for expansion (will be covered by baseboards)
Special Considerations for Kitchen Underlayment
Under Cabinets and Islands
If cabinets are already installed, you don't need underlayment under them—just around the perimeter. For islands, run underlayment underneath if the island is floating (not attached to floor), or cut around it if it's anchored down.
Radiant Floor Heating
If you have radiant heat, use thin underlayment specifically rated for radiant heat transfer. Standard foam can insulate too much and reduce heating efficiency. Check with your heating system manufacturer for approved underlayment types.
Height Transitions
Underlayment adds 2-4mm of height. Make sure this won't create a tripping hazard at doorways or transitions to adjacent rooms. You'll need transition strips to bridge height differences and create a smooth, safe transition.
Common Underlayment Mistakes to Avoid
Overlapping Seams
Never overlap underlayment rows. This creates a ridge that will be visible and felt through your flooring. Butt edges tightly together.
Installing Foam Under Tile
This is a disaster waiting to happen. Tile needs a completely rigid substrate. Foam compresses and flexes, causing tiles to crack and grout to fail within months.
Not Taping Seams
Unsealed seams allow underlayment to shift during flooring installation. This creates gaps, uneven areas, and can compromise the moisture barrier. Always tape every seam.
Ignoring Manufacturer Requirements
Some flooring warranties require specific underlayment types or brands. Check your flooring manufacturer's installation requirements before buying underlayment to avoid voiding your warranty.
Frequently Asked Questions
Do I need underlayment for LVP flooring?
It depends. Some LVP has built-in padding attached to the back (often called 'padded LVP' or 'attached underlayment'). If yours doesn't have padding, you should install foam or cork underlayment for comfort and sound dampening. Always use a moisture barrier over concrete subfloors. Check your LVP manufacturer's requirements.
What underlayment should I use for tile flooring?
Tile requires a rigid underlayment, not foam. For wood subfloors, use cement backer board (1/4 or 1/2 inch) or an uncoupling membrane like Schluter DITRA. For concrete subfloors, you typically don't need underlayment unless you're installing a crack isolation membrane or adding radiant heat. Never use foam underlayment under tile—it will crack.
Can I install underlayment over concrete?
Yes, but you need a moisture barrier first. Concrete absorbs and transmits moisture. Install 6-mil polyethylene plastic sheeting over concrete before adding foam or cork underlayment. Overlap seams by 8 inches and tape them. Many underlayment products for LVP and laminate include a built-in moisture barrier for this purpose.
Should underlayment seams line up with flooring seams?
No, underlayment seams should NOT align with your flooring seams. Install underlayment perpendicular to the direction your flooring will run. Butt seams tightly together and tape them. This prevents the underlayment from shifting and ensures your flooring seams don't fall on underlayment seams, which could create weak spots.
How much does underlayment cost?
Underlayment costs vary by type. Basic foam: $0.30-0.60 per sq ft. Premium foam with moisture barrier: $0.60-1.00 per sq ft. Cork underlayment: $1.00-2.00 per sq ft. Cement backer board (for tile): $0.75-1.50 per sq ft. Uncoupling membranes: $2.00-3.50 per sq ft. For a 120 sq ft kitchen, expect to spend $60-240 on underlayment.
Ready for the Next Step?
With your underlayment properly installed, you're ready for the main event—installing your new kitchen flooring.