Whether you are making changes to an existing glass-tiled area or starting a new installation project, it may be necessary to drill holes through the glass tiles to accommodate new fixtures or pipes. Although this may sound difficult, the process can be completed if you are willing to patiently work on the project.

Things You Will Need

  • Masking tape
  • Permanent marker
  • Drill
  • Diamond-encrusted carbide bit
  • Spray bottle with water
  • Scrap piece of MDF board (medium density fiberboard)
  • Plumber’s putty

Installed Tile
Tear off two pieces of masking tape and adhere the pieces to the surface of the tile in an “X” pattern over the area where you plan to drill a hole. This helps to keep the drill bit from wandering off the mark when drilling. Make a reference mark where you want to drill.

Attach the correct size diamond-encrusted carbide bit to your drill. If you plan to anchor a fixture to the tile, use a bit that is 1/8-inch larger than the anchoring screws. This extra space will prevent stress from being transferred from the fixture through the anchor and to the glass tile.

Position the tip of the drill bit over the mark. Drill at a slow speed with constant pressure. Keep the drill bit perpendicular to the tile to avoid chipping. Occasionally spray a mist of water around the drill bit to keep it lubricated. Drill to the desired depth.

Uninstalled Tile
Mark back of the glass tile where you plan to drill a hole. Place the tile on a scrap piece of MDF board with the backside facing up. Align the drill bit with the reference mark and drill a small pilot hole. Flip the tile over.

Take a ball of plumber’s putty and knead it into a ½-inch-diameter, 10-inch long roll. Join the ends of the putty to make a circle and place it around the area where you will be drilling. Press the circle of putty onto the tile to form a seal. This acts as a temporary dam to hold water while you are drilling. Fill the circle with water.

Align the tip of the drill bit with pilot hole and hold the drill perpendicular to the tile. Using a slow speed, gently apply constant pressure. Work at a slow pace and continue drilling until you have gone through the tile.

To drill larger holes to accommodate pipes, use a diamond coring bit.

Protect your eyes with safety glasses.


Tile floors are durable, attractive and easy to clean, but they can also be cold on your feet if they’re not well-insulated. You can insulate a tile floor in a number of different ways, depending on where the floor is located and whether you have access to the area that is underneath it. Methods will also vary depending on whether you are insulating an existing tile floor or installing insulation during construction of a new one.

Rigid Foam
Rigid foam insulation is a versatile product that is resistant to mold and moisture, making it ideal for under-floor applications. Rigid foam is manufactured in sheets that are 2-by-8 feet in size and 1- or 2-inches thick.

The thicker the foam, the better insulation it will provide for your floor. If your tile floor is on the ground floor of a house that is built on pillars, or a house with a very cold basement, you can cut down on the influx of cold air through your floor by fitting rigid foam in between the floor joists underneath the tile floor.

In-Floor Heating
Many houses are now built with in-floor heating. This type of heating features pipes that are set within a concrete slab in the floor.

The pipes circulate warm water and the heat from the water is transferred to the floor, which passively warms the room. This type of floor-based heating system is often used in conjunction with tile floors.

By insulating underneath the concrete slab, you can help send the heat from the slab up into the house rather than down into the ground. This type of insulation is done with a special type of rigid foam that is strong enough to resist the weight of the concrete on top of it.

Outside Walls
A lot of the cold that you feel coming up through your floor may be filtering in from the outside walls of your house. Particularly in older homes, the spaces between floor joists in the basement are often poorly insulated.

Cold air enters through the walls and fills the area between the joists, making the floor cold. You can block this air by fitting rigid foam panels in between the floor joists against the outside wall, then filling any gaps that are left with expanding foam.

Use insulated sub-flooring to keep a tile floor warmer if you are in the process of laying the tile floor. While the previous methods are appropriate for existing tile floors, this method can be incorporated into the floor itself as it is being built.

Put down a layer of rigid foam on top of the floor joists or the existing sub-flooring, then put down another layer of sub-flooring on top of it. The tile floor is attached to the upper layer of sub-flooring.

Be sure to fasten all layers of sub-flooring securely to the joists, so there is no movement when the tiles are attached.