| Tile over tile means exactly what it says, but in this | | | | glasses while sanding. The tiles may have been fired |
| case you're going to sandwich a layer of radiant | | | | with toxic lead glaze. |
| heating mats between the old and the new tile. Tile | | | | After sanding, vacuum the tile and wipe down with |
| over tile is an easy way to avoid the mess | | | | an all purpose cleaner. Pay special attention to the |
| associated with tearing up the old bathroom floor, | | | | areas untouched by the sander. |
| but requires thorough planning. | | | | Installation: |
| Deflection: | | | | Roll out the mats prefabricated to your specifications |
| Before you install a radiant heat mat over the old | | | | by the manufacturer. Some radiant systems, like |
| bathroom tile and install new tile over the mat, you | | | | Quickmat, are self-adhesive and require no mortar to |
| should check the floor for deflection. This is the | | | | secure them to the old tile floor. |
| maximum amount the floor can move under the | | | | If you're home has only one bathroom, cover the |
| anticipated load (you). Ceramic tile is hard and will | | | | heating mats during inevitable interruptions with |
| break or dislodge if the surface bends under the load. | | | | plywood or heavy cardboard. |
| Here's a simple test: | | | | Throughout the installation process, use a digital ohm |
| Stand in the middle of the bathroom floor and jump | | | | meter to check the resistance of the heating mats. |
| up and down. If the floor moves it has a deflection | | | | This will help you monitor the mats for short circuits. |
| problem and is not a good candidate for tile over tile | | | | Have your electrician connect the heating mats to |
| installation until you reinforce the sub-floor. | | | | the power source and install the thermostat. |
| Avoid That Sinking Feeling: | | | | Depending on the local electrical inspection |
| Since you're tiling over tile, you must plan in advance | | | | procedures, you might have to wait until the job is |
| to avoid making the vanity, toilet and tub look like | | | | inspected before you start laying tile. |
| they're "sinking" into the new floor. | | | | Trowel out the mortar over the mats. Some |
| One way to keep the bathroom fixtures from | | | | manufacturers recommend latex- modified or |
| looking swallowed up by the new floor is to remove | | | | epoxy-modified mortar and grout instead of |
| and reinstall the baseboard. Better yet, why not buy | | | | water-based multi-purpose adhesives. Mortar beds |
| new baseboard tile too? | | | | thicker than 3/8 inch should work fine for most |
| The raised height of the new floor will also require | | | | systems; they just take slightly longer to heat up. |
| you to adjust the length of the door(s) and possibly | | | | Since you won't be covering the entire floor with |
| install a new threshold. | | | | mats, under the toilet for example, make sure the |
| Preparation: | | | | mortar in these areas is level with the mortar |
| Remove or re-attach broken tile pieces. If you | | | | covering the heating mats. |
| remove them, wait until the floor has been sanded | | | | This might sound obvious, but don't bang the trowel |
| and thoroughly vacuumed before you fill the spaces | | | | on the mat or heating wire to remove excess mortar |
| with mortar. | | | | from the trowel. This could sever the heating wire. |
| If any of the tiles have checks wider than 1/8", you | | | | Finally you can install the new tile and baseboard. |
| should consider a crack isolation membrane. This | | | | Fire It Up! |
| membrane is a roll on product that you apply to the | | | | Your new radiant heated bathroom floor looks |
| old tile. The membrane allows the new floor to move | | | | beautiful and you can't wait to get warm feet. Go |
| independently of the old. | | | | ahead, but only for 10 minutes. Don't put the system |
| Next, sand the old tile so the mortar has a good | | | | into full operation until the mortar is fully cured. This |
| bonding surface. A belt sander would ensure a | | | | can take up to four weeks. |
| consistent bonding surface. | | | | See why thorough planning is so important? |
| Please make sure you wear a face mask and safety | | | | |