Removing Tile Mortar From Concrete Floor: A Detailed Guide

Removing tile mortar from a concrete floor is a daunting task. Even DIY enthusiasts among homeowners avoid dealing with it for as long as possible.

Yet, if you want to refresh the look of your space, it’s unavoidable.

Whether you’re renovating an old home or simply updating a room, understanding the best techniques and tools for the job is crucial.

This detailed guide will walk you through everything you need to know about efficiently and effectively removing tile mortar, keeping your concrete floor prepped and ready for whatever new flooring you have in mind.

Best Ways to Remove Tile Mortar from Concrete

You can try these methods to remove unwanted tile mortar:

• Using a Hammer and Chisel: Use a masonry chisel at a 45-degree angle to score the edges of the mortar. Begin hammering to slide the chisel under the mortar and separate it from the concrete. Sweep up loose debris after most of the mortar is removed.
• Using a Floor Scraper: This tool covers more extensive sections of thinset mortar quickly. Clear the area, hold the scraper at a 45-degree angle for optimal leverage, and apply steady pressure to push under the mortar layer.
• Using Power Tools: Rotary hammers, angle grinders, hammer drills, oscillating multi-tools, chipping hammers, and demolition hammers are good options for large spaces or stubborn mortar. Safety gear should be worn when using power tools.

After the mortar is removed, the surface should be prepped for new flooring by smoothing out rough spots with a sander or grinder and ensuring the area is thoroughly cleaned.

Planning Your Approach

Assessing the condition of the existing mortar and the type of tile that was used will help determine the best method for removal.

For instance, removing a thinset from concrete floors after ceramic tile removal may require different tools and techniques compared to dealing with larger areas of thinset left behind by porcelain tiles.

You should also set realistic expectations regarding time commitment and potential challenges that will help mitigate frustration during the process.

Make sure you are equipped with safety goggles, a dust mask or respirator, and ear protection.

Remember, cutting corners on safety can lead to unnecessary risks, including lung problems from inhaling fine particulate matter and eye injuries from sharp fragments.

Using a Hammer and Chisel

One of the most basic tools for removing tile mortar is the tried-and-true combination of a hammer and chisel.

This method involves manually chipping away at the mortar, bit by bit. It allows you to control the force applied and minimise damage to the underlying concrete surface.

It’s an excellent approach for tackling areas around delicate fixtures or in tight corners where power tools might be too cumbersome to operate.

Here are simple steps for clearing tile mortar using a hammer and a chisel:

1. Wear safety goggles for eye protection, a dust mask to prevent inhaling particles, and gloves for hand safety.
2. Choose a masonry chisel (3/4 to 1 inch) and a heavy-duty hammer. Check if your chisel is sharp.
3. Place the chisel at a 45-degree angle at the thin set’s edge. Tap the chisel lightly with your hammer to score the mortar edges.
4. After scoring, position the chisel at a 60-degree angle. Begin firmly hammering to slide the chisel under the mortar and separate it from the concrete.
5. Keep hammering in small sections until most of the mortar is removed.
6. For the remaining thin layers, switch to a flatter angle and tap lightly. Take care not to damage the concrete floor.
7. Sweep up loose debris after most of the mortar is removed. For a smooth finish, sand down rough patches or use a finer chisel to scrape off residual mortar.

This method is a labour-intensive process that requires patience and elbow grease but can sometimes offer more control than power tools, especially in delicate areas or when working around obstacles.

Using a Floor Scraper

For those looking for a middle ground between manual chiselling and power tool efficiency, the floor scraper presents an attractive solution.

Unlike the finer point of a chisel which targets small areas, a floor scraper is designed with a wide blade, making it an excellent choice for covering more extensive sections of thinset mortar quickly.

Here is a guide on how to use a floor scraper to remove tile mortar:

1. Clear the area of any furniture and sweep to get rid of loose debris. Don’t forget to wear goggles, gloves, and a respirator for safety.
2. Hold the floor scraper at a 45-degree angle for optimal leverage and control to avoid substrate damage.
3. Use steady, firm pressure to push the tool under the mortar layer; use short jabbing motions for tougher sections.
4. If faced with stubborn mortar, dampen it lightly with water for ease of scrapping but avoid excess moisture.
5. Periodically pick up debris with a broom, dustpan, or shop vac to prevent hardening and improve visibility.
6. Upon mortar removal, inspect the floor for overlooked patches; use the scraper or light sanding for a smooth finish.
7. For a pristine floor surface suitable for new flooring, vacuum thoroughly to collect any remaining dust or debris.

The physical effort involved falls somewhere between hammering away with a chisel and handling heavier, vibration-intensive power tools.

With the right technique, leveraging your body weight and maintaining a consistent angle, a floor scraper can significantly reduce the labour involved in mortar removal.

Power Tools Speed Up the Process

For more extensive projects or when faced with particularly stubborn thinset mortar, turning to power tools might be your best bet.

Using these, it’s important to wear safety gear to protect yourself from injuries. The use of goggles and gloves is highly recommended to keep the dust and debris from affecting you.

It’s always advisable to refer to the user’s manual for proper handling instructions to ensure safety and efficiency.

Here are various tools you can use:

Rotary Hammer

This high-power tool efficiently chips away the stubborn tile mortar. Equipped with a chisel bit, it breaks down the mortar, making it easier to remove.

A rotary hammer with an SDS (slotted drive system) max-fits chisel bit affords even greater efficiency in removing old tile mortar without damaging your concrete floor.

The SDS system provides enhanced energy transfer from the tool to the bit, making it better for removing those persistently adhered areas of thinset.

You can attach a chisel bit to the rotary hammer to effectively chip away at tile mortar. Hold the rotary hammer at a slight angle and apply pressure while allowing the hammering action to break up the mortar. This tool is especially useful for removing thick or stubborn mortar.

Angle Grinder

An angle grinder is another powerful tool you can use. It comes with different types of discs — diamond abrasive discs are ideal for this kind of job. It efficiently grinds off the hard mortar.

Install a diamond abrasive disc on the angle grinder and use it to grind off the hard mortar by moving the grinder back and forth over the mortar.

Hammer Drill

With the right bit, a hammer drill can be used to remove tile mortar. Although it may not be as powerful as a rotary hammer, it makes up for it with its maneuverability.

Insert a specialized bit into the hammer drill and use the hammering action of the drill to chip away at the tile mortar by holding the drill at a slight angle and applying pressure while drilling.

Oscillating Multi-Tool

This power tool is handy for reaching tricky areas like edges and corners where larger tools might not work as well. It does an excellent job scraping away mortar residue.

Attach a scraping accessory to the oscillating multi-tool and use it to scrape away mortar residue in hard-to-reach areas such as edges and corners by gently moving the tool back and forth.

Chipping Hammer

Explicitly used for tasks like removing tile mortar, a chipping hammer makes the work smoother. It uses air pressure for heavy-duty chipping.

Use the chipping hammer to chip away at the tile mortar by holding it at a slight angle and tapping it against the mortar with a hammering motion.

Demolition Hammer

For larger spaces and thicker mortar, a demolition hammer is ideal. It’s one of the most powerful tools that can break down thick layers of mortar quickly.

Use the demolition hammer to break down thick layers of mortar by holding it at a comfortable angle and applying pressure to break up the mortar with the hammer action.

Prepping for New Flooring

Once you’ve managed to remove the majority of the tile mortar from your concrete surface, achieving a smooth base is critical before installing new flooring.

You may find that using a handheld sander or an angle grinder with appropriate sandpaper helps in smoothing out any residual rough spots.

Grinding not only ensures a clean surface but also helps in promoting better adhesion for new floor installations.

Be wary of potential dust generation during this step. Always wear protective equipment and employ a vacuum system.

The final step in removing old tile mortar is a thorough clean-up. Ensuring that all dust and debris are cleared away will guarantee a clean slate for whatever flooring project comes next.

Wet mopping can help settle any remaining dust particles and provide an opportunity to inspect your work closely. Check if no spots were missed during the removal phase.

How Stone Protection Can Help You Remove Old Tile Mortar from Your Concrete Floors

If you’ve tried different ways to remove thinset from your concrete floors and it just won’t budge, calling for professionals to do the job is the best course of action. 

With years of experience and industry-grade equipment, Stone Protection can remove unwanted tile mortar off your concrete floors and prep them for the next set of tiles you want to add.

Contact us today!

Frequently Asked Questions

What dissolves tile cement?

Various types of acids, like hydrochloric or muriatic acid, can dissolve tile cement. However, they should be used with extreme caution as they are highly dangerous.

What is the best tool for removing mortar?

The best tool for removing mortar largely depends on the amount of mortar to be removed. Chisels, hammers, or a handheld rotary tool equipped with a grout removal accessory can be used for smaller projects. For larger tasks, an electric chisel, hammer drill or an angle grinder may be more effective.

Can vinegar dissolve mortar?

Vinegar can help remove mortar but cannot fully dissolve it. It’s effective for cleaning off residue or small amounts of mortar. Still, for larger amounts of hardened mortar, muriatic acid would be more effective.

Does baking soda harm concrete?

No, baking soda will not harm concrete. It is sometimes used as a cleaning agent for concrete.

What is mortar stain remover?

Mortar stain remover is a product specifically designed to remove hardened or set mortar stains from various surfaces. These are often acid-based solutions. Always carefully follow the manufacturer’s instructions when using such products.

How to safely complete a DIY project when removing ceramic tile adhesive?

Make sure to wear protective gear, work in a well-ventilated area, and use proper tools such as a chisel or floor maintainer.

Can I remove old thinset from a concrete floor without causing damage?

Yes, it’s possible. Use gentle methods for best results.

Is it necessary to remove all the old thinset before installing new floor tiles?

Yes, it is necessary to remove all the old thinset from the concrete subfloor before installing new floor tiles to ensure a smooth and even surface for the new tiles.