Installing Laminate Over Existing Floors: What You Need to Know

Laminate is a floating floor. The planks lock to each other and rest on the old floor without nails or glue, so laminate can go over almost any floor that is flat, solid, dry and fastened down. It can't go over anything soft, or anything that floats itself.

Hardwood: Yes, if the boards are tight, flat to within 1/8 inch over 6 feet, and at 12% moisture or less. Wood glued or nailed straight to concrete is the exception, because the makers rule it out.

Old laminate or click vinyl plank: No. The North American Laminate Flooring Association says existing laminate "is not a suitable subfloor for new laminate installation." The old floor comes up first, and it comes up easily.

Ceramic or porcelain tile: Yes, once the grout lines are filled flush and any loose or cracked tiles are fixed. Tile on a concrete slab also needs a plastic vapor barrier over it.

Sheet vinyl or linoleum: Yes, for one layer that's stuck down, flat and not cushioned. In an older house, don't sand it to level it, because it may contain asbestos.

Carpet: No, at any pile height. The carpet, pad and tack strip all come out first.

Existing floor	Laminate over it?	What decides it
Nailed-down hardwood	Yes	Tight, flat, 12% moisture or less
Wood glued to concrete	No	Makers exclude wood fastened to a slab
Old laminate, click vinyl plank	No	A floating floor has to come up
Ceramic or porcelain tile	Yes	Grout filled flush, no loose tiles
Sheet vinyl or linoleum	Yes, one layer	Stuck down, not cushioned, no tears
Carpet of any pile	No	Carpet, pad and tack strip come out

The sections that follow take each floor in that order, from hardwood to carpet. After them come the underlayment, the height the new floor adds at doors, stairs and the dishwasher, a checklist for doing it yourself, and answers to a few more questions.

Can you put laminate flooring over hardwood?

Yes, you can put laminate flooring over hardwood when the hardwood is stable, flat and dry. The North American Laminate Flooring Association (NALFA), the laminate industry's trade group, calls hardwood "viable if the hardwood is stable and flat." Mannington's installation guide lists wood flooring among the floors its laminate can cover. Most of the work is checking the hardwood before you hide it.

What to check on the hardwood first

Start by walking every foot of the hardwood and listening for squeaks. Boards that creak, move or sit higher than their neighbors need fastening, and Mohawk's instructions say to "nail down any loose areas and apply a leveling layer if necessary." Set any nail heads that stick up.

Next, lay a 6-foot straightedge across the floor in a few directions. Mannington allows 1/8 inch of variation over 6 feet, with high spots sanded or ground down and low spots filled with a cement-based patch. Boards that cupped or crowned after an old leak are the usual trouble.

Check moisture last. Mannington and Mohawk both set 12% as the most moisture a wood floor can hold under their laminate, and a pin-type moisture meter reads it in seconds. If the house sits over a crawl space, Mannington also wants a vapor barrier on the crawl space ground and at least 18 inches between the ground and the wood.

Wood fastened straight to concrete fails the check. Mannington calls wood "directly fastened to concrete" unsatisfactory, and Inhaus and Shaw rule it out too. That includes parquet or strip flooring glued down in a basement or on a slab.

Do you need underlayment for laminate over hardwood?

Yes. Laminate over hardwood needs an underlayment, the thin pad between the old floor and the new planks, either rolled out on its own or bonded to the back of the planks. Mannington says an appropriate underlayment "must be used when installing over all hard surfaces" and caps it at 3 mm thick. A plank with an attached pad already has its underlayment, so skip the second foam layer.

A separate plastic moisture barrier over hardwood is a brand-by-brand call. Mohawk's instructions ask for 6-mil polyethylene sheeting under every floating install unless the pad has a barrier built in. Mannington and Inhaus call for the barrier over concrete, and Mannington's concern with a wood floor is the crawl space under the house. Go by the instructions in the carton of the plank you choose.

How to install laminate over hardwood

Once the hardwood passes those checks, installing laminate over it runs in this order.

Fasten loose boards, set raised nails and vacuum.
Fill or grind anything past 1/8 inch over 6 feet.
Confirm the wood reads 12% moisture or less.
Pull the base shoe, quarter round and old transition strips.
Undercut the door casings, the trim around each door opening, to the height of a scrap plank sitting on a scrap of pad.
Roll out the underlayment with seams butted and taped, unless the planks have a pad attached.
Lay the planks "crosswise to the direction of the existing subfloor," in Mohawk's words, so each plank bridges several old boards.
Leave the maker's expansion gap at every wall, the space that lets the floor move, and nail the trim to the wall, never to the floor.

Covering hardwood instead of refinishing it

Covering hardwood with laminate doesn't harm it. Laminate floats, and Mannington's instructions say "Do not secure flooring to underfloor," so no nail or glue goes into the oak. If you or a later owner want the hardwood back, the laminate and pad come up and the wood is still there.

If what you want is the oak itself looking new again, that's a refinishing job, not a laminate one. Covering is the better fit when the boards are too worn or patched to look good, or when you want a color or style the oak can't give you.

Can you lay laminate over laminate?

No, you shouldn't lay new laminate over old laminate. NALFA's guide to suitable subfloors says "Existing bamboo or laminate flooring is not a suitable subfloor for new laminate installation." The installation instructions from Mannington, Inhaus and Mohawk, three of the laminate brands A & B Flooring carries, list only existing floors that are stuck or fastened down.

Why one floating floor can't sit on another

Old laminate floats on its own pad and shifts a little every season as the humidity changes. A new floating floor on top would lock its joints over a base that moves and gives underfoot.

The makers want the opposite: a thin, firm base. Mannington caps the pad under its laminate at 3 mm, and Inhaus caps it at 1/8 inch and even sets a minimum firmness for it. An old laminate floor on its old pad is thicker and softer than any of that. On a soft base, click joints flex with every step until they open up or push into ridges, which installers call peaking.

Inhaus also wants an existing floor "well bonded to the subfloor." A floating floor is loose by design, so it can't meet that test.

Laminate over vinyl plank and other floating floors

Laminate over luxury vinyl plank (LVP) depends on how the vinyl went down. Click-together vinyl plank floats just like laminate, so it comes up. Glue-down vinyl plank or tile that's still stuck tight counts as a vinyl floor covering, which Mannington and Inhaus accept when it's one layer, flat and well bonded.

NALFA's list is looser. It calls vinyl tiles and planks suitable when they're flat and in good condition, without separating floating from glued. The brands' instructions are what a warranty follows, so treat any floating floor, including floating engineered wood, the same way as old laminate.

Old laminate comes up easily

Taking up old laminate is the easiest tear-out in flooring. There's no glue and there are no nails, so the planks unlock row by row and the pad rolls up. Mannington notes that its laminate "can be carefully disassembled and reassembled several times" when the planks aren't damaged.

What's under the old laminate decides the next step. A concrete slab gets a 6-mil plastic vapor barrier before the new floor. A wood subfloor gets the same 1/8-inch flatness and 12% moisture checks as hardwood.

Can you put laminate flooring over tile?

Yes, laminate can go over ceramic or porcelain tile once the surface is flat and every tile is firmly stuck. Mannington accepts ceramic tile on one condition, that the "grout joints must be leveled." NALFA says the same in its own guide and adds a check for cracked or loose tiles.

Filling the grout lines

Grout lines get filled flush with the tile face before any underlayment goes down. Where a plank crosses a sunken grout line, it has nothing under it, so it flexes each time someone steps there and the locking edge slowly wears.

A cement-based patch or floor leveler does the job, the same Portland-based patch Mannington names for low spots. Inhaus sets the tightest limit, saying any abrupt lip over 3/64 inch across 4 inches has to be corrected. That catches tile edges that sit higher than their neighbors, not only the grout.

Loose, cracked or hollow tiles

Loose or cracked tiles have to be fixed before you cover them. Tap across the tile with a screwdriver handle, and listen for a hollow sound, which means that tile has let go of its mortar. Inhaus wants an existing floor "well bonded to the subfloor" with no cracks or chips, so re-set or replace those tiles first. Natural stone gets a more cautious answer from NALFA, which says yes "only if the surface is completely smooth and level."

Tile on a concrete slab or in a basement

Tile on a concrete slab needs a vapor barrier, a plastic sheet that stops moisture rising from the concrete, laid over the tile before the laminate. Inhaus puts it plainly: "If vinyl, linoleum, or ceramic tile is installed over concrete, a vapor barrier must be installed over it." The tile doesn't count as the barrier.

Basements need one more look. NALFA says to avoid floors with drains, and Inhaus says its laminate suits any room "as long as it does not have in-floor drainage." If the basement has ever had water on the floor, settle that first. The guide to managing subfloor moisture covers the tests.

Laminate over bathroom and kitchen tile

Laminate over bathroom tile only works with a laminate its maker rates for bathrooms. NALFA says laminate doesn't suit bathrooms "unless specified as waterproof by the manufacturer," and Mannington has installers fill the gap around the toilet flange with 100% silicone. For a full bath or a laundry room, A & B Flooring often points people to waterproof luxury vinyl instead.

Kitchen tile is a good candidate, with one warning. The new floor sits higher than the tile, and at the dishwasher that extra height can trap the machine under the counter unless the floor is planned around it.

Can you lay laminate flooring over linoleum or sheet vinyl?

Yes, laminate can go over linoleum or sheet vinyl when it's one layer, stuck down everywhere, flat and not cushioned. Mannington accepts "existing vinyl floor coverings" but not "loose lay, heavily cushioned, or multiple layers." Mohawk says linoleum and vinyl don't have to be removed, and NALFA adds that "padding is required."

Cushioned vinyl and floors with more than one layer

Cushioned vinyl and stacked layers of vinyl come out before laminate goes in. Inhaus says heavily cushioned floor covering and resilient floors, meaning vinyl, linoleum and the like, "that exceed one layer in thickness should be removed." Both are soft, and a soft base flexes the laminate's joints the same way an extra pad would.

Bubbles, tears and lifted seams mean the vinyl isn't well bonded in those spots. On a newer floor, repair them first. On older vinyl, don't cut or scrape them until the floor has been tested for asbestos.

Why covering old vinyl can be safer than removing it

If your vinyl or linoleum is old, covering it may be safer than pulling it up. The US Consumer Product Safety Commission says asbestos "is found in some vinyl floor tiles and the backing on vinyl sheet flooring and adhesives." The EPA adds that you can't tell whether a material contains asbestos just by looking at it, and that sampling is a job for a trained, accredited professional.

The EPA's advice on flooring is direct: "When asbestos flooring needs replacing install new floor covering over it, if possible." The same page says not to sand or level asbestos flooring or its backing. Inhaus and Mohawk print that warning in their instructions too, and both say to presume old resilient flooring contains asbestos unless you know it doesn't.

That changes the prep. Fill low spots with patch instead of sanding high ones, and don't scrape or grind the old floor. In the older ranches and split-levels common around Huber Heights and Dayton, the vinyl may be original. If it has to come out, the EPA says removal belongs to a trained, accredited asbestos professional.

Can you put laminate over carpet?

No, laminate should never go over carpet, whatever the pile height. Mannington's instructions say "Do not install Mannington Laminate Flooring on top of carpeting," and Inhaus, Shaw, Mohawk and NALFA all agree the carpet comes out first.

Low-pile carpet isn't a substitute for underlayment. Mohawk calls carpet a "damp-porous" covering, one that lets moisture in and holds it, and carpet compresses unevenly under a floating floor. Pull the carpet, the pad, the tack strip (the nailed wood strip that grips the carpet's edge) and every staple. The plywood or OSB underneath suits laminate once it passes the same flatness and moisture checks, and NALFA lists both as suitable.

Underlayment when laminate goes over an existing floor

Laminate over an existing hard floor always needs an underlayment. NALFA says underlayment "supports the locking system," and Mannington requires one "when installing over all hard surfaces." The guide to choosing laminate underlayment compares pad types room by room. This section covers what changes when an old floor is underneath.

Planks with an attached pad

If the planks have a pad bonded to the back, that pad is the underlayment. That's why Shaw's installation page says "Not all floors will require underlayment so be sure to ask!" Don't add a second foam layer under an attached pad, since Mannington and Inhaus both cap the cushion at 3 mm, or 1/8 inch. When you compare planks in A & B's laminate selection, the spec tells you which kind you're looking at.

Moisture barriers over concrete and over wood

Over concrete, or over tile or vinyl sitting on concrete, NALFA, Inhaus and Mohawk all call for a vapor barrier, usually 6-mil polyethylene. Mannington also sets a limit for testing the slab, allowing no more than 5 pounds of moisture per 1,000 square feet in 24 hours on a calcium chloride test.

Over wood, the brands split. Mohawk wants a 6-mil poly barrier under every floating install unless the pad has one built in, while Mannington's concern over wood is the vapor barrier on the crawl space ground. When the instructions differ, the ones in your carton win.

How much height laminate adds, and where it causes trouble

Laminate over an existing floor raises it by the thickness of the plank plus the pad. A plank from Mannington's Restoration Collection is 12 mm, just under 1/2 inch, and with a pad at Mannington's 3 mm limit the floor rises about 15 mm, a little under 5/8 inch. That height shows up at doors, doorways, stairs and kitchen appliances.

Doors and door casings

Door casings, the trim around a door opening, get undercut so the new floor slides under them. Mannington says to cut them 1/16 inch higher than the new flooring, using a scrap plank as the guide. Some doors will also need a trim off the bottom, and Mohawk's instructions say to check that every door opens and closes once the floor is in.

Transitions to the next room

Where the new floor meets a room you're not redoing, a reducer covers the step. A reducer is a sloped strip that ramps down to the lower floor. Between two laminate rooms, a T-molding covers the joint and leaves room for movement. Mannington wants a T-molding break in any run over 55 feet, and Mohawk sets it at 40 feet, which matters in long open floor plans.

Stairs

Plan the stairs before anything else. The International Residential Code, a model building code, says the tallest riser in a flight, the vertical face of a step, can't be more than 3/8 inch taller than the shortest. Dayton-area building departments such as Moraine's list the same 3/8-inch limit. Adding 5/8 inch of floor at the top or bottom of a staircase changes that one step by 5/8 inch.

The usual fixes are to take the old floor up near the stairs so the new floor ends at the old height, or to plan the stair treads as part of the same job. Either way, decide before the first plank goes down.

Dishwashers, cabinets and kitchen islands

In a kitchen, a raised floor can trap the dishwasher under the counter. GE's installation instructions say a dishwasher "MUST be installed to allow for future removal from the enclosure if service is required." A new floor laid up to the front of the opening can leave it too tall to slide out, so run the new floor into the opening or check there's room to lower the legs.

Cabinets stay put, and the laminate stops at them. Inhaus says a floating floor must not be pinned down by cabinets, and it allows a free-standing island on top only if it weighs 500 pounds or less and isn't fastened through the floor. Fixed islands, like cabinets, go in before the floor.

Baseboards and the expansion gap

Laminate needs an expansion gap at every wall, and the size depends on the brand. Mannington asks for 5/16 inch, Mohawk and Inhaus for 3/8 inch, and Shaw's installation page for 1/2 inch. Mohawk lets you either pull the baseboards or leave them and cover the gap with a molding. Either way, trim is nailed to the wall, never to the floor. Ohio's humid summers and dry winters are why the gap matters, and how humidity and seasons affect your laminate flooring explains the movement.

Can you install laminate over an existing floor yourself?

Yes, a careful do-it-yourselfer can install laminate over an existing floor, as long as the old floor passes the checks and the instructions are followed. Shaw calls laminate "a budget and DIY-friendly flooring option," then adds that "you must adhere to installation guidelines to ensure that your flooring is installed properly and maintains its warranty coverage."

A floor that passes every check in this table is ready for laminate, and each failed check adds a prep step.

Check	Passes if	If it doesn't
What the old floor is	Hardwood, tile or one layer of glued vinyl	Carpet, cushioned or floating floors come up
Flatness	Under 1/8 in gap over 6 ft	Fill low spots, grind high spots
Tile	No hollow sound, no cracks	Re-set tiles, fill grout flush
Wood moisture	12% or less on a pin meter	Find and fix the moisture first
Concrete underneath	Slab tested dry, vapor barrier planned	Test the slab before buying
Height	About 5/8 in clears doors and stairs	Undercut casings, plan stairs and dishwasher
Old vinyl in an older house	Covered in place, patched, not sanded	Have an accredited pro test it first

The jobs that get harder are leveling a large area, stair edges, kitchens with built-in appliances, and slabs with moisture. That's where many homeowners hand the work off.

A & B Flooring, the family-owned flooring store on Taylorsville Road in Huber Heights, handles laminate flooring installation across the Dayton area. Its installers check the existing floor during the measure and recommend whether it can stay, and its subfloor prep starts by flattening the subfloor. You can also read what installation day looks like before you decide.