How to Remove Thinset from Cement Board | 2 Methods

After removing the tiles from the cement board, you will see hardened mortar on it. These leftover mortars are known as thinset. If you are willing to use new tiles on the cement board then first you will need to remove the thinset from the cement boards.

Removing the thinset is challenging because, it has a strong bond and if the removal process isn’t done in such a manner, then you might end up damaging or breaking the cement board. Although the work is hard to do but can be done quite easily by using the water-putty knife combo or by using a hammer drill

In this article, we have provided the steps that you can follow to remove thinset from cement board with ease. So, be with us till the end and start removing them from the cement board.

How to Remove Thinset from Cement Board

Methods for Removing Thinset from Cement Board

There are two mostly followed methods for removing thinset from cement board. The first one is by using warm water and a putty knife and the other one is using a hammer drill. 

If the thinset thickness is not that much thick then warm water and a putty knife will get the job done. And for thicker thinset, you will need to use a hammer drill.

Method 1: Use Warm Water and a Putty Knife

Using warm water and vinegar mixture on the thinset will help you to weaken the thinset and it help to remove them much easier. You will need,

  • 1~2 L of water.
  • 250 ml of Vinegar.
  • 1-inch putty knife.
  • Hand maul.
  • Angle grinder.
  • 5~7 inch diamond cut wheel.
  • Gloves and safety glass.

Here are the steps that you will need to follow –

  • Take approx 1.5 L of water and pour 250 ml of vinegar and mix them. Now, boil the water.
  • After boiling, gently pour the water over the thinset and wait for about an hour.
  • After that, you will see that there are cracks in the thinset.
  • Take a putty knife and hand maul. Place the putty knife at a 45-degree angle to the thinset. Now, start the removal process. While using the haul hammer, make sure you are not providing that much force.
  • Repeat the process until the thinset totally come off.
  • After that, take the angle grinder and attach the diamond cut wheel. Now, move the grinder to the thinset area. It will take off the leftover thinset and will make the surface smooth.

Method 2: Use a Hammer Drill

For thicker thinset, you will need to use a hammer drill from removing them from the cement board. Here are the things that you will require –

  • A 3-inch tile chisel bit.
  • Hammer drill.
  • 1-inch putty knife.
  • Hand maul.
  • Safety gears.

Follow the below-mentioned steps and remove the thinset from the cement board easily. 

  • Firstly, take the hammer drill and attach the 3-inch tile chisel bit to the drill. 
  • Now, place the chisel head or blade at a 45-degree angle and pull the trigger. 
  • Start chipping the thinnest carefully and gently.
  • After chipping them off, take an angle grinder or you can use a putty knife to take off the leftover thinset.

Repeat the steps until the thinset is taken off properly.

Frequently Asked Questions and Answers (FAQs)

Can I use dishwashing liquid instead of vinegar for removing the thinset?

Yes, you can. But the effectiveness can be guaranteed. If the thinset is on the tiles then it will work perfectly. Otherwise, you should stick with the warm water-vinegar mixture.

Can I use hydrogen peroxide for removing the thinset?

Yes, you can use hydrogen peroxide. Generally, it’s a weak acid like vinegar. By mixing it with warm water, you can weaken or loosen the thinset easily.

Does wetting thinset is a good idea?

A big yes! It’s definitely a good idea. Warm water helps to decrease the integrity of the thinset and it starts making them loosen. Once they are loosened, you can remove them with a putty knife.


Lastly, you will need to be careful enough while removing the thinset. Because if you over pressured on the thinset then the putty knife or hammer drill may leave cracks on the cement board. So, that’s why stay focused and conscious while chipping the thinset!

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