I was working on getting through the ceiling of my garage to install some eye-bolt lag screws to hang a boxing heavy bag.
I had issues finding the joists which was handled in: Finding ceiling joists overhead
In the process I realized that my drill bits may be insufficient.
I had a 5/16" eye bolt screw to install. First thing I needed to do was expose 5/16" through the ceiling so I can hit the joist. I started with a 5/16" dewalt masonry bit on a dewalt hammer drill. It did nothing. I then switched to a 3/16" bit (not sure what type, probably one of those multi-purpose ones) which worked fine. However, I still needed more space to push my eye screw through so I then switched back to the 5/16" bit to bust through the remaining width. It worked. However, I had to push hard and if i hit the wood, the drill bit turned red at which point I stopped.
I am looking for a good drill bit set to make the pilot holes (as small as possible) and find the joists. After that I need something to expose the wood. Not sure why masonry didn't work initially. Any recommendations on what to use? I assume hammer drill is correct to get through the ceiling. Picture below. Thanks!
Best Answer
Not all masonry bits work in hammer-drill mode; some are strictly for rotary drill use. I have a feeling you burned up the 5/16" bit by drilling at high speed. Heat kills drill bits, and for masonry, speed=heat; so, speed kills.
You should be able to drill numerous 5/16" holes with a single bit. Keep your speed (and pressure) down, stop to let the bit cool off occasionally, use water (if possible) to lubricate and cool the bit (this may be difficult when drilling overhead). And use the correct technique for the bit that you have (i.e. don't use your drill motor in hammer mode unless you have a hammer-drill bit).