If your bathroom or kitchen remodeling project involves replacing the tiles, chances are you’ll be removing thinset at some point. Thinset is applied to a surface to allow tiles to adhere to it.
When you pull off the tiles, traces of the thinset remain stuck to the wall or floor. These remnants should be removed before you lay new tiles in order to create a smooth surface where the new tiles can lay evenly.
Thinset isn’t a glue, but rather a type of mortar. Once set, it can’t be simply scrubbed off or dissolved. Removing thinset is a labor-intensive process that generates a large amount of dust, so it requires some preparation. The right tools and methods make the job a little easier.
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Safety Precautions Are Essential
Grinding or breaking up thinset produces dust that contains silica. Inhaling silica can permanently damage your lungs and contribute to lung cancer, so protective gear and clothing is a must for this job. Wear protective eye gear and an N95 respirator. An ordinary dust mask is less than ideal, but sufficient for small jobs. Because you’ll be working with noisy, vibrating equipment, wear ear plugs to protect your hearing and leather gloves to prevent blisters. Thinset dust is difficult to wash out of hair, so a hat is recommended.
The equipment commonly used to remove thinset moves at high speeds and includes sharp components, so use caution when operating it. To prevent the equipment from overheating, work in 15-minute intervals and allow the equipment to cool in between.
Thinset applied before the early 80s may contain asbestos. If you suspect yours does, have it tested before you remove the tile to avoid harming your health.
Power Chisel or Demolition Hammer
For most home DIY remodeling jobs, the most practical way to remove thinset is to chip it off with a power chisel or jackhammer. These electropneumatic power tools are designed to be fit with a large chisel blade or similar blade bit. As the tool operates, the blade moves with a rapid hammering motion that breaks the thinset away from the floor. These tools are typically available to rent by the day at large home improvement centers.
To use a power chisel or demo hammer to clean the thinset off your floor, place the blade at an approximately 45-degree angle to the surface of the thinset. Pull the tool’s trigger and slowly move the blade forward in small sections of 1 or 2 feet at a time. Continue working in small sections until the floor is clean. Adjust the angle of the blade as necessary to get up under the thinset, but avoid angles much steeper than 45 degrees, which could damage the blade. If the thinset is particularly stubborn, you can apply a small amount of pressure as you move the tool, but it’s usually not necessary.
These tools may leave small patches of thinset on the floor. You can remove leftover patches using an angle grinder fit with a diamond grinding cup wheel. Bear in mind that this tool produces a large amount of dust, so wear protective gear and cover any nearby items you want to keep clean.
In some situations, thinset may not come off easily with a jackhammer. If you find using a jackhammer or similar tool is slow going or you have a large floor to clean, consider using a floor buffer. This tool can be rented from most large home improvement centers.
You’ll also need a diamond abrasive polishing tool such as the Malish Diamabrush, a Werkmaster Thinset Removal tool or a similar attachment that fits the type of floor buffer you’ll be using. Dust control attachments are also available and will help keep your air and house clean as you work.
To use a floor buffer to remove thinset, just turn the machine on and move it slowly back and forth in small arcs as you walk forward with it. Slow movements give the polishing tool time to grind down the thinset.
If you need to remove thinset from a wall, chiseling it off with a putty knife will get the job done quickly with the least amount of dust. Use a putty knife with a sharp blade and a hammer-end handle, a flat-ended handle that can be hit with a hammer.
Set the blade of the putty knife at a 45-degree angle to the thinset on the wall and firmly tap the end of the knife with a hammer to chisel off the thinset. Avoid hitting hard or the knife could break. The thinset should come off in small chunks.
You may not be able to remove all traces of thinset this way, but you should be able to get the surface smooth enough to lay tile evenly. If you want a smoother surface, remove the remaining traces of thinset with an angle grinder fit with a diamond grinding cup wheel.
Safe and Efficient Cleanup
When the job is done, you’ll be left with a floor full of broken tiles, chunks of thinset, and a pile of dust. Renting a small dumpster is often the most convenient way to collect the debris for disposal, but a large trash can will also work.
Wearing your respirator, carry the larger tile pieces out to the dumpster, and use an outdoor broom to sweep up the remaining debris and move it to the dumpster. Then use a soft-bristled indoor broom to sweep up as much dust as you can. With a wet-dry vacuum, pick up any lingering dust and finish by wet mopping.
Nearly any time you replace tile, you’ll need to get the old thinset off the floor or wall in order to lay your new tile evenly. Using a power tool such as a power chisel or floor buffer is often the most efficient way to get the job done. Chipping the thinset off with a putty knife is another option if you’re cleaning a wall or a small area of floor.
If you’re not able to find an appropriate power tool for the job, contact a professional. While it’s possible to clean a large space with a small tool such as a putty knife or angle grinder, you may find the time and mess involved aren’t worth the money saved.