If you’re taking up a tile floor with the intent of reusing the flooring, leftover thinset can get in the way. Unfortunately, it can prove tough to remove, especially if you want to save the tile. At the same time, there are no real shortcuts.
In most cases, the only way to remove thinset from tile is to soak it and then scrape it up. While you can use a hammer drill, that might damage your tile. Additionally, you can try using chemical solutions like vinegar or light concentrations of muriatic acid. In either case, it will require a lot of manual work.
This guide is about removing thinset from tile, if you want to remove thinset from concrete or another porous material, check our guide here.
How to Remove Thinset from Tile
Thinset is a soft mortar, normally made by mixing concrete with sand. This very fine concrete is smooth enough to spread extremely thinly, making it ideal for setting tile.
It also bonds to the bottom of the tile and the concrete, forming a very sturdy fixative for tile flooring. Unfortunately, when you go to remove your tile for reuse, you have to find out firsthand just how sturdy.
In addition, if you’re removing thinset from tile, you’ll have to take care not to chip the tile. That can mean spending more time per area than you would with a concrete floor.
Things you’ll need:
- Wide putty knife or thinset knife
- Hammer drill (optional but must be used with caution to avoid damaging the thinset)
- Grout removal tool if you have to remove thinset from grout
- Rotary sander
- 250-grit sandpaper
- Lightweight hammer
- Disposable gloves
- Large bucket or basin capable of holding the tiles (if you’re using muriatic acid, you’ll want an acid-safe container)
1. Soak the Tile
If you’ve already taken your tiles up, you can get started cleaning thinset off the backs by soaking the tiles. Here, there are a couple of different methods you can use:
i. Vinegar to Remove Thinset – Vinegar is a great first choice for soaking tile to remove thinset. This is a light acid which is very unlikely to damage the tile.
Here, you can simply add the tiles to a basin of water with about 1 part vinegar to 8 parts water and allow them to soak for about 30 minutes. Then, pull the tiles out one at a time and add a new one as you finish.
If you don’t want to use vinegar, dish soap or lemon juice will both work similarly.
ii. Muriatic Acid – If a vinegar solution doesn’t work to loosen the thinset, it’s possible to use a light muriatic acid solution. However, it’s important to keep in mind that if you use too much acid or leave the tile in too long, it will damage the tile.
In addition, muriatic acid is best only applied to the top of the tile, because it may dissolve some types of tile. Therefore, this should be a last resort option.
However, even soaking thinset in plain water will help. That’s because thinset is made with a lot of sand.
When sand absorbs water, it swells. That will soften the mortar and make it easier to scrape off. You’ll still have to actually scrape it off – however, it will be easier.
2. Scraping thinset off tiles
Brace a tile where you can easily apply pressure. Sitting on the floor with the tile against your leg or a piece of furniture is a great way to start.
Then, use a wide and sharp scraping blade to scrape the thinset off. If it’s difficult to put enough pressure on the scraper, you can use very gentle taps with a light hammer to help.
However, if you tap too hard and the putty knife goes into the tile, it could chip or crack.
Here, buying a special thinset blade can help. Thinset blades are normally machine sharpened beyond putty knives, average about six inches wide, and come with attachments for a handle or a hammer drill.
In either case, you can scrape off more thinset with them than you can with a putty knife. If you have a lot of tile to clean, they will save you time.
3. Sanding off Thinset
If you put a large grit sanding pad on a palm sander, you can often sand off a lot of thinset from the back of tile. However, if you do so, it’s important that you choose wet/dry sandpaper.
Then, soak your tile before sanding. This will reduce the amount of thinset dust in the air.
In addition, you’ll want to use a dust mask rated for the purpose. That’s important because concrete dust is toxic and can cause significant problems to your lungs. Make sure you sand in a well-ventilated area or outdoors if you take this route.
However, you might not want to sand as your first approach. It might be faster to pass over everything with a scraper and then sand what’s left. If you can get a scraper under thinset, you can normally just peel it up. If you use a sander, you’ll have to sand down the whole layer until the back of the tile is smooth. That can also take time.
You’ll also want to occasionally rinse your tiles off to see how you’re progressing.
4. Cleaning Up
You should always rinse off tiles and then go over them with a sander or with a scraper to get any small bits you might have missed. You can also try setting the tile down and seeing if you can rock it. If it doesn’t sit perfectly flat, there’s still thinset on the back and you should remove it.
Thinset Removal Techniques
Here are some examples of other areas you may want to tackle.
If you’re removing thinset from porcelain tiles, you can take almost the same approach as with any other tile. However, you’ll normally want to be more careful with the tiles.
For example, you’d never want to soak porcelain in any mixture of muriatic acid. You’ll also want to avoid using steel wool or harsh scrapers on the front. Instead, try using a sponge and hot water first. If that doesn’t work, you can gently scrape any thinset off the front of the tile.
However, the best option is to always try to remove any thinset from the front of the tile before the thinset hardens.
If you have to remove hardened thinset from tile joints before applying grout, you can usually do so with a grout removal tool. This might be a rotary tool, a butterfly tool, or a simple grooved scraper.
However, you will have to manually remove it from every line. Here, you should soak the floor in a vinegar and hot water solution before you go to remove the grout. Give the water 10-20 minutes to soften the thinset. Then, scrape it up.
Removal of Thinset Haze From Tile
If you’ve put your tiles back in and have thinset haze on the front or even clumps of thinset, you want to get it off and as quickly as possible.
Here, you can try using a simple stiff sponge or brush first. Soak the floor in vinegar and water and let it set.
Then, scrub the floor with a stiff brush or a stiff sponge. Do not use steel wool as it can scratch and dull your tile.
If that doesn’t work, use a scraper with a razor blade to manually scrape the thinset haze from the tile. However, in most cases, using a light acid on the top of the tile will get the haze off.
Frequently Asked Questions
Removing thinset from floors is never going to be easy. Instead, you’ll almost always have to manually scrape it off. That can take a significant amount of time and effort. If you still have questions, these answers should help.
Will muriatic acid remove thinset from tile?
It’s normally safe to use light concentrations of muriatic acid on the front of tile. However, you shouldn’t use it on the back of most tile. That’s because porcelain and ceramic could disolve in muriatic acid.
In addition, if you leave muriatic acid on tile too long, it could eat through the enamel. This could cause your tile to dull or the tile to dissolve.
However, applying muriatic acid to tile for a few minutes can help you clean up thinset haze if all else fails.
How do you remove hardened thinset?
If you have hardened thinset on top of tiles, you can usually scrape it off with a razor blade. A razor blade is sharp enough it’s less likely to damage the tile than a putty knife. However, it will take longer, so it’s only really useful for small patches.
How do you remove thinset from a wood floor?
If you’ve gotten thinset on a wood floor the only answer is usually to get the floor wet. However, if you’ve applied thinset on a plywood floor, it may be simpler to replace the plywood. That’s because you can’t really get plywood wet.
This means the only real way to get the thinset up will be to use a hammer and chisel. And, that can significantly damage the floor. However, if you’re able to spend several days on the job, you can get tile mortar up without damaging the floor too much.
Does vinegar remove thinset?
Vinegar does not remove thinset. However, it can help to dissolve the bonds in the concrete. This means it might be easier to scrape up.
Unfortunately, your thinset will never be easy to scrape up, but it might be looser and might flake up better. So, vinegar and hot water are great tools to use with a scraper or a hammer drill.
Removing thinset from tile can be a tricky job. That’s especially true if you have old or delicate tiles and you can’t buy a few new ones to replace any you break.
The best option is to soak the tiles in hot water and vinegar, use a good Thinset scraper, and manually remove the mortar from the backs of each. That will take time, but it’s the most reliable way to clean your tiles for re-use. Good luck.