How to Remove Thick Concrete Underlay
Thick concrete underlay, or underlayment, is a type of floor installation backing typically comprised of cement and sand. This mortar underlay is necessary to provide a smooth, even and durable surface on which to lay tiles or stones. Without this underlay, the floor would "float" and shift, causing it to come apart. When remodeling a space, there may be cracks or stains in the underlay. Generally, these defects can be repaired or removed. However, if the damage is significant, you will need to remove the concrete underlay. Does this Spark an idea?
Things You'll Need
- Respirator
- Safety goggles
- Leather gloves
- Screw gun
- Cold chisel
- Hammer
- Floor grinder
- Shop vac
Instructions
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1
Clear the room of any furnishings and home decor. Removing concrete underlay will create a lot of dust, and anything inside the area where you're taking out the concrete will be covered in mortar dust.
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2
Put on a respirator, safety goggles and leather gloves.
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3
Unfasten the threshold trim at the entryway, using a screw gun, and set it aside. You should be able to see the two "seams" between the tiles or stones, concrete underlay and the subfloor.
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4
Hold a cold chisel at a 75- to 80-degree angle between the tile or stone and the underlay. Strike the cold chisel with a hammer to begin taking up the tiles or stones. Once the first tile or stone is broken free from the concrete underlay, chisel and hammer up the remaining tiles or stones to completely expose the underlay. This will be a very labor-intensive and lengthy task.
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5
Hold a masonry chisel between the concrete underlay and the subfloor at a 45-degree angle at the threshold of the entryway. Strike the masonry chisel with the hammer to begin breaking the underlay away from the subfloor. Continue from the entryway into the room, chiseling the underlay off the subfloor.
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6
Plug in a floor grinder once the underlay has been chiseled away from the subfloor, and run the grinder across the subfloor to remove the bonding agent holding the underlay against the subfloor.
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7
Use a shop vac to clean the subfloor once all the bonding agent has been removed with the floor grinder.
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