I am putting in a new thermostat. I cut a 1" hole in the wall at about eye level. I have an endoscopic camera and i see that at about 3 feet off the floor there is a wooden board that runs parallel to the floor.

What do professionals do in such a situation? I was thinking of cutting another 1 inch hole right above the board, and then trying to drill through it at an angle, and hope that it is not too thick.

I should mention that i also have access from the basement, but there is a beam directly under the wall that i am working on, so i cant just drill a hole from under there - more over i would need a very long bore, which i do not own.

Its an old 1930s house - if that makes a difference

  • the second hole will mean more patching, but will allow you to drill without buying the bits Steven mentions. Be sure to fire caulk as I mentioned below.
    – HerrBag
    Feb 25, 2013 at 14:58

1 Answer 1


Best way to work through this is with a flexible drill bit. Most common length is 6'. You can either drill down from your hole or up from your basement. There is a tool to help you guide the bits:

Flexible Drill Bit
(source: homedepot.com)
Bit Placement Tool
(source: homedepot.com)

If 6' is not long enough you can buy bit extensions. Most of the bits have a small hole at the end of the bit you can use to attach a pull string once the bit is drilled through to its destination; this making pulling a wire back through relatively easy. They are also usually self-tapping so you just aim it where you want and let the drill do the rest of the work.

Make sure to mark any important infrastructure like power and gas lines - you don't want to hit any of those while drilling.

  • 1
    I have and use these bits. I've found the screw (the self feed at the tip) of the smaller diameter bits to stop pulling easily.. the 3/4 bit seems to 'draw' better. Off axis drilling also seems to stop drawing easily.
    – HerrBag
    Feb 25, 2013 at 14:41
  • The hole should also be fire stopped after installing the cable, either fire caulk or a rated mineral wool. bit.ly/X6g7f5
    – HerrBag
    Feb 25, 2013 at 14:52
  • @HerrBag The point of these flexible drill bit is to drill a hole inside a wall far which is hard to access. How do you apply caulk to the hole in the firebreak which is two feet below the hole in the wall? Sep 15, 2013 at 0:51
  • 1
    @StefanLasiewski You can only firecaulk the first hole, in basement.
    – HerrBag
    Sep 15, 2013 at 1:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.