Skip to Content
This post may contain affiliate links. As an affiliate of retailers(like Amazon), we earn from qualifying purchases.

Can You/Should You Tile Over Old Floor Adhesive? (How To Remove)

With all the impressive flooring options available on the market, it is hard not to want to remodel a room here and there. Among several other factors taken into account when undergoing such a project, what to do with leftover adhesive from the floor you remove is a crucial issue that is often overlooked or downplayed.

You can tile over your old floor adhesive by placing a barrier down in the form of thin-set, underlayment, a false floor, or using a floor leveling compound before tile installation. To achieve the strongest bond and preserve your moisture barrier, you should scrape, sand, or strip the old adhesive.

Putting tile flooring

In the article below, we will go over what to consider when addressing the old glue under your floor. We will discuss different the different actions you can take

Can You Tile Over Old Floor Adhesive? Things You Can Do

Tile adhesive flooring

While it is possible to tile over old floor adhesive, you should consider all of your options before moving forward. Do you know what type of glue was used before? If so, use the same product used in the previous flooring installation; by using adhesives with different formulas, you run the risk of an unstable bond, opening up the door to structural or moisture concerns.

If you can’t use the same adhesive or glue – most people don’t know how their floor was installed ten years ago before they bought the place – it is best to remove it altogether.

  • Scrape it up with a floor chisel;
  • Use an oscillator to get it off;
  • Use a floor stripping compound;
  • Rent a heavy-duty floor stripper

Should You Tile Over Old Floor Adhesive? Better To Remove

Floor adhesive

It isn’t a good idea to tile over old floor adhesive in the long run. Unless you intend on building a false subfloor off of the flooring below – as one might in a carpeting installation, for example – your best bet is to remove all of the pre-existing glue and thin-set before laying down the glue you will be using for your tile. Complete removal will ensure your new flooring will bond to the subflooring properly.

A quick fix will lead to long-term problems.

  • Mold and Mildew problems. Mold and mildew could form in places where glues have degraded and lost their vapor barrier properties. According to the EPA, you should address mold issues immediately to prevent adverse health effects like Sick Building Syndrome or asthma attacks in allergy-prone individuals.
  • Cracks in the grout. When you tile over old flooring glues, you allow the new adhesive to interact with the old compound, leading to bond degradation. This interaction can cause cracks in your grout, which require attention to prevent trips or tile damage.
  • Crumbling flooring. With a weakened bond below the surface, tile can slide and break, especially if the floor below wasn’t level beforehand. This chemical reaction between the new and old adhesives can happen over time, putting the integrity of both the top and subfloor at risk.

How To Tile Over Floor Tile Adhesive (How To Remove)

Tile floor removal

Good, you’ve decided to remove that old glue after all. Do you know what kind it was? What flooring did you remove to get to it? The table below may help you gain some insight into what type of glue you are dealing with. When you come across adhesives that are used with most materials, this will include carpet.

 

Pros

Cons

Used With

Remove With

Latex

  • Easy to work with
  • Less VOCs
  • Water-soluble, making it easy to clean
  • Slow to dry
  • Must be used with underlay (breaks down with moisture)
  • Formulated for use with most materials
  • Water
  • Chipping
  • sanding

Urethane

  • Strong bond
  • Moisture-curing
  • Flexible for impact and vibration resistance
  • Hard to clean
  • Plastics
  • Wood
  • Rubber
  • concrete
  • Mineral spirits
  • paint thinner
  • Acetone
  • sanding

Epoxy

  • Very strong bond
  • Quick to dry
  • Forms moisture barrier
  • Good gap-filler
  • Difficult to spread
  • Not suitable for outdoor use
  • most materials
  • Isopropyl alcohol
  • Acetone
  • sanding

Modified Silane

  • Easy to work with
  • Moisture-curing
  • Helps with swelling and shrinking
  • Weak bond
  • Pre-finished hardwoods
  • Sanding

Solvents

  • Easy to work with
  • Easy to clean
  • Extremely strong bond
  • Smelly and lots of VOCs
  • Weakens concrete adhesives
  • Plastics
  • Wood
  • Metals
  • paper
  • Chipping
  • sanding

Mastic

  • Suitable for vertical tiles, like backsplashes
  • Low-traffic flooring solution
  • Water-soluble
  • Pungent odor
  • It doesn’t fill gaps
  • It doesn’t perform well in high moisture areas
  • Porcelain tile
  • Glass tile
  • Ceramic tile
  • Concrete
  • Exterior grade plywood
  • Chipping
  • sanding
  • water

Thinset Mortar

  • It only takes a thin layer for a good bond
  • Inexpensive
  • Wet installations; waterproof
  • Slow dry time
  • Cracks easily
  • Porcelain tile
  • Glass tile
  • Ceramic tile
  • Concrete
  • Natural stone
  • chipping/sanding

Asphaltic Cutback

  • Made a highly durable compound for securing vinyl flooring
  • CONTAINS ASBESTOS
  • Vinyl flooring prior to 1984
  • Safety equipment recommended
  • DO NOT remove in a way that would release dust

Now that you have a better idea of what kind of glue you are working with let’s go through the step-by-step process of removing the old adhesive on your floor. Remember to use proper safety precautions, wearing eye protection, a mask to prevent dust inhalation, and gloves to protect your hands from cuts and scrapes.

  1. Clean and prepare your area. Please make sure all furniture, tools, new flooring, and wires are out of the designated area before removing the old flooring and its complimentary glue.
  2. Remove old flooring. If you haven’t done so already, remove the old flooring recommended based on the material. Once removed and properly disposed of, sweep or vacuum any remaining debris.
  3. Use a floor chisel to scrape glue. Using a 45° angle, scrape the glue off the floor in a shoveling motion, careful not to gouge the floor with the chisel’s sharp edge. Use a hammer or a rubber mallet to tap on the chisel’s handle in the shoveling motion’s direction to pry up especially tough spots; sweep or vacuum.
  4. Use an oscillator to sand down rigid adhesives. If you still have excess glue stuck on your floor, you can use an oscillator, or a sander, which you can rent at your local hardware store for a small fee. The oscillator can also be used to add an extra abrasive surface for new adhesives to latch onto when using a compound that is compatible with an old glue.
  5. Use a floor adhesive stripping compound. If you have some especially old or tough adhesive to remove, apply a generous amount of stripping compound and let it sit for a while, dissolving the bonds over time. You can use something like this Adhesive Stripper Super Remover from Amazon. We like this stuff because it is cheap and it works on a variety of glues. If you want a more green solution, apply vinegar to your glue overnight to soften it up before trying to scrape it with your floor chisel again.
  6. Rent a heavy-duty floor stripper. If you have a large room or multi-room project, you may want to invest in a heavy-duty floor stripper to cut your removal time in half. You can rent one for a fee and a deposit at your hardware store, but keep in mind that you will be responsible for purchasing a new blade for it in most cases, and you will need a large vehicle to get it home.

Can You Tile Over Old Floor Adhesive?

Man with question marks above his head

Are you having trouble getting all of the old glue off of your floor? Are you worried about the labor and cost associated with removal? If you have an adhesive compatible with the one already in place, you can successfully tile over it. In some cases, scoring the old glue with a sander or knife will allow your new adhesive to bond to it better.

Pour Leveling Compound Over It

If you use a leveling compound to raise your floor height or fill in holes, gaps, and cracks, you can leave the old adhesive. Put a barrier over the old glue, or pour directly over if you are sure the chemicals are compatible or plan on using an epoxy adhesive, which will effectively seal the surface.

Score the Old Glue

Some glues do well stacking on top of subsequent layers. Cut small scores into the old glue’s surface with a utility knife or go over it with a sander to make the surface rough. The extra texture will give your next layer of glue more pockets to hold.

Build a False Subfloor

Building a false floor is typically seen when putting carpet in a garage or basement with a concrete slab. Still, if you have an especially cracked or uneven floor to contend with, you may find better stability with a false floor.

Measure your room(s) and place 2”x4”s around the perimeter, taking care to include support beams in the middle of the room; this is where you will secure and connect the edges of your plywood sheets.. Close your gaps with caulking, and you’re ready to use your new subfloor! For more stability and in especially wet environments, use cement board instead of plywood.

Although the process can seem daunting, it is best to remove all of the old glue to ensure maximum floor stability. It is tempting to do part of the work with an “I’ll get to it later” sort of attitude, but not correctly securing your floor from the get-go may cause expensive or dangerous problems down the line. It is always worth the time to go over your work for quality assurance.

Can You Tile Over Glue on Concrete?

Man with question marks above his head

It is possible to go over old glue with a thin-set mortar before laying down tile on concrete to establish a barrier. Thinset mortar is a durable combination of cement, fine sand, and a liquid barrier that allows the cement to hydrate appropriately. This mixture allows strong bonds to occur in a thin layer. You can use a thicker layer of mortar to level and fill gaps or cracks in the substrate floor.

When attempting to use mastic, keep in mind that it is an organic compound that is water-soluble. Its extreme sticking power makes it an excellent adhesive for tile, but it shouldn’t be used in high moisture content areas, like a bathroom or mudroom. Over time, exposure to moisture in the air may cause sagging and sliding to occur and could contribute to a mold or mildew infestation later on down the line.

If you plan on using a floor leveling compound to help with an uneven slab issue, you may be able to get away with patching over the glue with some thin-set before pouring over it. I would recommend using this Simple Pre-Mixed Thin-Set for a quick waterproof patch in a convenient, pre-mixed solution and Ardex Feather Finish Self Drying Cement for a mold-resistant compound that is ready to use on porous subfloors, like plywood or concrete

The thin-set comes in a small container, so it’s perfect for small patch jobs, and Ardex’s concrete solution creates a creamy texture that is easy to work with and eliminates crumbling problems found in concrete mixes.

Do I Need To Remove Old Glue Before I Lay Tile??

Man writing a question mark on a white wall

While labor-intensive and time-consuming, you will thank yourself later for removing the glue under your old floor. Any remnants of adhesive could compromise the bond between the subfloor and your new tile. If you want to install a floor that will stay put without being maintained frequently, you will want the strongest – and therefore cleanest – foundation possible for your flooring.

  • Are you using a different adhesive for your new tile that might be chemically incompatible with the pre-existing stuff? If you have a water-soluble latex adhesive leftover from some old linoleum, for example, you would not want to attempt to use polyurethane or a solvent-based adhesive as they would react with the old glue, detracting from the floor to floor bond.
  • Are you planning on using a floating floor? If you are installing a floating floor with plywood or cement board and 2″x4″s, you may not need to remove old adhesive as the false or floating floor will be a new level surface to tile on top of.
  • Are you using a thick mortar bed? Suppose you are going for a layer of mortar with your tile to guarantee a superior hold even with substrate movement. In that case, odds are the mortar will be thick enough that smaller amounts of adhesive won’t affect the bond’s stability. With excessive or antagonistic glues, removal is the best option.

Peel-and-Stick Tile Over Old Adhesive

Tile flooring

Peel-and-stick tile is an excellent alternative for those who don’t want the hassle and cost of ceramic or porcelain tiles. The tiles have a backing sheet like a sticker which you peel off, and then, after you have correctly lined it up with your flooring, you stick it into place.

They are waterproof and super simple to lay and, with advances in printing technology, can be designed to imitate nearly any flooring option available. When you want to convert an old floor space fast, peel-and-stick is a great flooring option.

But can you put it over your old adhesive? Survey says fat chance, Paulie. Peel-and-stick tiles are thin so that any floor imperfections will be superimposed onto the tile itself. Holes, cracks, or old glue will need to be adequately leveled out and cleaned off of the floor’s surface before applying the tiles. Failure to do so will cause an unstable seal between tile and subfloor.

  • Tiles may loosen, looking disagreeable;
  • Trip hazards may cause injuries to inhabitants;
  • Loose floor material may allow damage to the subfloor beneath;
  • Unlevel floors may affect surrounding tiles with increased traffic.

Overall, the consensus seems to be that it’s best to do the extra bit of (grueling) work so you can reap the reward of a sturdy and stunning floor.

What Is the Best Adhesive Remover for Concrete Floors?

Handyman with tools in the background

Goo Gone

Hands down, in most situations, we swear by the amazing citrus power of Goo Gone, which you can get here in a large quantity from Amazon for large projects.

  1. Soak up some Goo Gone with a sponge or dish towel;
  2. Place the sponge or towel on the adhesive;
  3. After at least 30 minutes to an hour, test effectiveness;
  4. Repeat if necessary

Some DIY fanatics have found the best success with adhesive removers after they have allowed their soaked sponge or towel to sit on the old glue overnight, allowing time for the bonds to dissolve. After spending the night being melted by our Goo Gone companion, the old adhesive should be malleable enough to remove with the floor chisel.

Super Remover

A close second in terms of overall value would be the Super Remover Adhesive Stripper, which is cheaper than Goo Gone. It comes in a fast-acting gel formula that boasts the ability to strip most adhesives within 15 minutes, eliminating the need for an overnight soak. Super Remover’s Adhesive Stripper formula also contains less volatile chemicals, like methylene chloride or NMP, than products of the same caliber.

How to Pair TCL TV to Xfinity / DIRECTV / Roku / Universal remote
← Previous
Can You Put Carpet Over Laminate Flooring?
Next →
Comments are closed.