How to Cut Into Terrazzo Flooring

Developed in ancient times, terrazzo flooring is one of the most durable and beautiful floor coverings ever invented. Occasionally you will need to cut into terrazzo flooring to repair or replace a worn spot. Follow the steps outlined below to cut into a terrazzo floor.

Step 1 - Determine If Your Terrazzo Floor Is Poured Aggregate or Tiles

It is easy to tell if your terrazzo floor is poured aggregate or tiles. Look for thin silvery seams down the edges of a hallway, and around large 48-inch squares on the floor to distinguish a terrazzo tile floor. The tiles will be about 1 inch (25 mm) thick. If your floor has no visible seams or tile markers, it is most likely poured concrete terrazzo.

Step 2 - Choose the Most Suitable Method to Cut into the Floor

One option for cutting into the floor is to use a shot blaster on a poured aggregate floor. This material is too dense and irregular to be cut with a diamond blade saw. To cut into a tile floor, you can use a circular masonry saw and a diamond blade, cooled with water from a bottom-mounted hose.

Step 3 - Use a Shot Blaster

A shot blaster breaks up the surface of poured aggregate terrazzo, concrete, and masonry. It prepares these surfaces for filling holes and cracks with resin and fresh aggregate as needed. The shot blaster provides dustless cutting. It pummels the surface of the terrazzo with tiny steel pellets from a centrifugal wheel at high velocity.

A separator picks up unwanted contaminants and the steel pellets, removing the contaminants and recycling the pellets back into the centrifuge. The shot blaster will also etch the surface, so adhesives and epoxies will stick better.

Small pellets provide fine surface etching, while large pellets dig in more deeply. A shot blaster must be operated by a trained technician.

Step 4 - Prepare to Cut With the Diamond Blade Masonry Wet Saw

Prepare an entry point for the saw blade by creating a deep chip at a corner of the terrazzo tile with a cold chisel and sledgehammer. Make this entry groove as long as the diameter of your blade.

Step 5 - Cut with the Masonry Wet Saw

Masonry wet saws come with 8 feet of water hose, so place your saw, water, and power supply close to your cutting job. While wearing your safety glasses and hearing protection, start the water feed for the saw. Turn on the saw and insert the blade carefully into the entry groove.

Step 6 - Guide the Wet Saw

Follow a tile line closest to the part needing repair or replacement. The tile line is a dense grout, easier to cut through than concrete and aggregate.

Make a new entry slice with the chisel and sledgehammer when you need to cut at a right angle. Place the wet, turning blade into the new entry slice and continue cutting. Watch continuously for large aggregate lumps. Move the saw through these lumps very slowly to prevent blade recoil.