Drill bits for concrete.

[Steliz]

I want to attach my air filter unit to the ceiling of my workshop but I'm having some fixing issues.
The ceiling is concrete with a coat of render (I'm in the basement) and the unit weighs 29kg and has 4 screw in hooks near the corners. I bought a set of 4 hooks with a 40mm threaded section that came with their own plugs and, according to the packet, are rated for 60kg. The unit will be over the door which means that I will walk under it numerous times a day and I would prefer that it didn't kill me while protecting my lungs!
My issue is with drilling the holes. I have a fairly cheap corded drill (750w) and masonry bits but I can't get through the concrete to a depth of 50mm. I know the bits can't be very good quality as I've rounded over 3 so far! What would be a better choice of bit or should I consider a different approach?

 

[Trevanion]

Are you drilling into steel reinforcement?

 

[Phil Pascoe]

You got there before me.

 

[sunnybob]

Steel reinforcement rods are spaced out through the concrete. You know if you hit one, the drill goes slowly sideways.
But there are some really, really cheap and nasty chinesium masonry drills out there, which struggle getting through hard cheese.

Buy a known make drill bit (bosch,de walt, etc etc), and if you only get 2" in, move the hole a half inch in any direction.
If the holes end up not in line with the holes in the unit, just use some metal plate and bolt the unit to the plates that are screwed to the ceiling.

 

[Doug B]

From the sounds of it you need an SDS drill & bit, if you are hitting a bit of aggregate in the concrete you’ll struggle to get through it with an ordinary masonry hammer drill & bit.

 

[Steliz]

Are you drilling into steel reinforcement?

That did cross my mind but I have tried 3 of the 4 holes and had a problem with them all and there are no sparks or evidence of rust anywhere. The first hole was a struggle for about 10/15mm through concrete then I hit a void and I had to go upstairs and check I hadn't gone through the living room floor! The next 2 I could get about 20mm in and that was it, progress stopped. I tried new bits but they got destroyed with no more progress.
I put some lighting up last year using fairly short screws and that was tough going too.

 

[Distinterior]

SDS drill.....Job done!

 

[GarF]

That or the Bosch multi-construction bits (the ones with the flutes painted blue) these have worked for me round our house where the bricks are about the hardest I've ever come across. Including with the hammer action turned off for the sake of accuracy. Amazing
G

 

[Aquachiefofficer]

A couple of years ago I bought a tungsten carbide tipped Proteco masonry bit to drill through 100mm concrete. I believe they're available as SDS and standard versions. I would recommend them.
Paul

 

[RobinBHM]

youve probably hit some flint aggregate

thats hard stuff

a Titan SDS would be your friend -or equivalent Chinese cheapie -if they are still in stock, I heard there was a bit of an issue with supply chains these days -I'm not sure what, there's been nothing on the news

 

[Steliz]

OK, thanks for the replies. I did buy an SDS hammer drill a little while ago but as I didn't expect to use it much I didn't want to spend too much so I bought one in Lidl. The chuck cracked in half at the first pull of the trigger!

 

[HappyHacker]

+ 1 for decent drill bits. On a job the customer was helping me by drilling some holes in a concrete panel using his decent battery hammer drill. He was getting nowhere. I loaned him one of my Bosch bits and straight in no problem.

I agree with the posts saying there maybe problems with rebar, the fact that you get in the same distance on all holes indicates there is possibly something there.

An SDS is the answer as they generally make light work of most stuff, note I said generally.

 

[owen]

Either try an sds drill or first it's worth trying the blue bosch multi construction drill bits in a normal drill. They're loads better than cheap bits. Also worth starting with a small bit before the bigger one to make your life easier.

 

[Racers]

Get or hire a SDS its the only thing that will reliably work on concrete.

Pete

 

[Phil Pascoe]

I tried to put holes in walls when we moved. I couldn't find my SDS so I used a Ryobi that I bought cheaply in a charity auction specifically to fit my drill stand. Even on hammer with decent bits it wouldn't cope with blocks full of elvan - the bits were coming out pointed and red hot. I borrowed my bil's Bosch SDS and with decent bits I did the job with no difficulty whatsoever (I found my DeWalt SDS the following day).
Use decent kit. If you emptied my drill case the cost of drill bits, core bits etc. would add up to way more than the drill cost.

 

[Deadeye]

I had a similar problem drilling into the wall for my wood rack. I think the old stable wall has engineering bricks in it. I have a decent hammer drill (Milwaukee) and bought a good bit - but got nowhere.
I invested in a mid-price SDS and it's life changing!

 

[Bm101]

Just for knowledge probably no help to the OP. (Sorry) DIY use but for the price this sds set is bang on. I've knocked them about a bit and not a dent. My house is either a sandstone extension or concrete render that kills normal cheaper bits. Like I say diy use. But I'm well happy with the performance. For the price and size variety it's unreal.
https://www.screwfix.com/p/sds-plus-sha ... eces/8849v

Re: the original op's issue. There is one other possible solution.... check the weight bondings. Seem ok tbh if braced while drying.
https://www.ct1.com/our-products/power-grab-n-bond/

 

[Steliz]

All sorted now, thanks for all the input. I bought a Bosch bit that had a 4 way (cross) tip and borrowed an SDS drill and it went through the concrete like a hot knife through butter. I turned the ceiling into Swiss cheese trying to find a place where I didn't hit any voids, there seemed to be a lot!

Re: the original op's issue. There is one other possible solution.... check the weight bondings. Seem ok tbh if braced while drying.
https://www.ct1.com/our-products/power-grab-n-bond/

Ha! The concrete ceiling has a 10mm layer of render and an uncomfortable amount of voids so I'll give this a miss, thanks Bm101.

 

[Bm101]

All sorted now, thanks for all the input. I bought a Bosch bit that had a 4 way (cross) tip and borrowed an SDS drill and it went through the concrete like a hot knife through butter. I turned the ceiling into Swiss cheese trying to find a place where I didn't hit any voids, there seemed to be a lot!

Re: the original op's issue. There is one other possible solution.... check the weight bondings. Seem ok tbh if braced while drying.
https://www.ct1.com/our-products/power-grab-n-bond/

Ha! The concrete ceiling has a 10mm layer of render and an uncomfortable amount of voids so I'll give this a miss, thanks Bm101.

Tools for the job. Good result in the end Steliz. Job done at any rate.

 

[gregmcateer]

From the sounds of it you need an SDS drill & bit, if you are hitting a bit of aggregate in the concrete you’ll struggle to get through it with an ordinary masonry hammer drill & bit.

I agree. If your not going to need an sds drill again, see if a mate nearby has one. Or hire one if no local mate.
If you're near Stourbridge, you're welcome to borrow mine
HTH