Tips on this site are like buses - wait ages then two come at once!
Today I want to share the method I came up with for drilling radiator pipe holes through our newly-tiled hall floor. This I managed with no damage to the tiles immediately surrounding the hole, which is always something to worry about. Here's how:
1. First thing to do is fix your rad to the wall
2. Find a piece of wood large enough for you to rest all your weight on with both knees and drill a hole in it (more on the hole in a mo)
3. Site the hole directly below the rad valve and mark the skirting to show where the board should line up with once you've removed the rad and are ready to drill. In the shot below I'm using a short piece of pipe that's just long enough to help line up the valve with the floor.
4. Do the same for the other side and remove the rad from the wall. Put the board back in its place and squirt some water in the hole. As you can see below I've hired a 30mm diamond-core drill bit and drill from a local hire shop. It can get warm so nice to try and water cool it.
5. With all your weight on the board you can start drilling. The whole idea of the board is to stop the drill slipping off in any directions and scraping the tiles. After a while you've got a "pilot" hole going and can remove the board and carry on without it. I'd suggest cleaning up as you and giving a fresh squirt of water as well. Don't try and wham the drill through in one go. Each hole took me about 1o minutes!
6. Once you're through the tile and glue (sorry, as Shaun "Tiler" Taylor says, "adhesive") you can remove the plug and there you have it - a hole. All you need now is a normal wood drill to finish the hole off through whatever's below the tiles (2" of plywood and chipboard in our case).
7. You're probably wondering why the 30mm hole for 15mm piping!? Well, 30mm is the smallest core drill the hire shop had. That's why the board has the large (32mm!) hole in it. But it's nice as it give us a bit of room to play with when it comes to plumbing time. I already knew I'd be covering the holes with collars (like below) so it's not an issue for me.