Drilling Concrete Wall

[seanb02]

Well folks, it would appear that the concrete wall has bested me. Maybe I am doing something wrong, really haven't done much in the way of concrete drilling before. Anyway, the walls in my shop are 8" thick poured concrete ~100 years old.

I am trying to mount a shelf I welded together high up on the wall to install an oil heater for the shop. To mount the shelf I need to install four 1/2" bolts through the wall, due to potential for vibrations I would much rather have a bolt going through the wall rather than a regular anchor.

Then I need to drill another hole for the fuel supply line ~3/4", and a hole for the exhaust vent 3" diameter. For the exhaust vent I do figure on having to rent some kind of tool to bore that somehow, but I figured the rest of the holes I could get through with a regular hammer drill.

Apparently I was wrong, starting with a new Milwaukee 12" long 1/2" bit after well over an hour of drilling I only made it 5-6" deep on one of the holes. Either my technique is all wrong and I burned up the bit, or I just don't know what I'm doing, or maybe this is just plain impossible. Having to drill while standing on a ladder doesn't really help the situation.

What are my options here to get some holes done? Thanks folks!

 

[seanb02]

I should also clarify that I am not trying to do this with a cordless drill that has a "hammer" mode. This is a proper hammer drill, but perhaps it isn't quite a large enough one for the task? Also a picture of the shelf frame that I built that is going to be attached to the wall.

 

[Bert_]

Are you talking a little hammer drill that's mostly just a drill? or a roto hammer?

 

[Brian.Rheeder]

What you have is a hammer drill. What you need is a rotary hammer drill. Night and day difference. Go rent one from Home Depot or similar, and be prepared to be blown away at the difference.

Good luck. Old concrete is hard.

 

[finn]

Bosch or Dewalt SDS plus rotary hammer drill.


I imagine all the major manufacturers have a similar one, even HF.

You’ll be there for months with a conventional hammer drill.

 

[Roundhouse]

Bosch SDS plus demolition hammer drill is what you need

 

[Jlbc212]

What you have is a hammer drill. What you need is a rotary hammer drill. Night and day difference. Go rent one from Home Depot or similar, and be prepared to be blown away at the difference.

Good luck. Old concrete is hard.

^^^^ This! I have a Makita SDS Plus rotary hammer drill. It takes only a few minutes to drill a 3/4" hole through a 10" thick solid concrete wall. I never had need to track the exact time, but it's quick.

 

[Old Man Roger]

The secret with 100 year old concrete is 2 fold.
1-Keep the bit cool
2-Pressure
Concrete gets harder the older it gets.
If you don't position yourself so you can push hard on the drill then you will just heat and dull the bit in less than a minute.

Start with a new bit and dip it in a glass of water every few seconds of drilling. I know that sounds like a lot, but it works quicker than drilling with a dull bit.

This is worth saying twice..You have to position yourself so you can put good pressure on the drill. I like to have my back against something solid, but if you can maybe find something to hold onto with one hand?

 

[Hilltopmasonry]

What you have is a hammer drill. What you need is a rotary hammer drill. Night and day difference. Go rent one from Home Depot or similar, and be prepared to be blown away at the difference.

Good luck. Old concrete is hard.

My sds plus would have that drilled in about 25 seconds

Sds Drills through concrete like a hot knife in butter

Hammer drills are loud, obnoxious, and just annoying and pretty-much worthless



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[gemniii]

I'm sure many others will chime in with "more power".
Rotary hammer, I'd say the minimum would be something like a SDS or SDS plus in the 1-1/8" 11 amp size.
HF has them for $79 w/ coupon frequently.

 

[cderalow]

My sds plus would have that drilled in about 25 seconds

Sds Drills through concrete like a hot knife in butter

Hammer drills are loud, obnoxious, and just annoying and pretty-much worthless



Sent from my iPhone using Tapatalk

Fine for metals though.

SDS is a must for concrete.


Sent from my iPhone using Tapatalk

 

[seanb02]

I thought I had the right tool for the job, but apparently not! Didn't know there was any difference between hammer drill types once they get as large as the Milwaukee one that I have. So lets say I purchase this one:

https://www.harborfreight.com/105-amp-1-916-in-sds-max-type-pro-variable-speed-rotary-hammer-kit-63441.html

Not really going to get regular use, just every once in a while so I don't know about spending a bunch of money for a better quality brand. Would this be capable of doing the 3" hole for the exhaust port or would I still need to rent a different tool?

I would imagine that renting a tool would likely cost me $80 or so for a day, so if I can buy a decent one at twice that cost, then I would say it is worth it. So lets say under $200 what is the best bang for my dollar?

Also I see that DeWalt has 20v versions of SDS plus drills, and I am a sucker for cordless expanding my current DeWalt platform and would be willing to pay a bit more for one of those. Would that be enough of a drill or do I need to focus strictly on a corded unit? Thanks!

 

[Slowgsr]

3" core bit on a sds max will cut the wall, and any rebar. I actually just bought a 4" for my hilti drill last week

Other then that a sds plus drill and bits will cut the other holes, bits with 4 cutters work much much better then ones with 3 cutters.

 

[matt_i]

My sds plus would have that drilled in about 25 seconds

Sds Drills through concrete like a hot knife in butter

Hammer drills are loud, obnoxious, and just annoying and pretty-much worthless

Could not have stated this better

 

[seanb02]

Well, it appears that this Makita model is available for rental at my local Home Depot for $45 for the 4 hour minimum, or $64 for a day. Looks as though this particular drill goes for around $500 depending on where it is sourced from. Likely would get the job done better than purchasing a different tool for under $200?

https://www.homedepot.com/tool-truck-rental/Roto-Hammer-1-1-2/HR4010C/index.html

I would assume they have bits to rent as well at an additional cost, hopefully including the 3" hole saw. Perhaps this time around I should just go the rental route and see how it goes rather than purchase one?

Definitely not going to shell out $500 for a tool right now, and if a ~$200 tool won't be capable enough for this job and future things here and there as they come up then is renting this one my best bet?

Or do you folks know of something good in my price range that will definitely get the job done and last for a few other random projects here and there?

 

[dogdog]

you can try find a used one...
that link is for SDS-Max drills... other companies also sell them... If your current bits are not sds-max ones, you'll have to either buy new, or buy sds-max to chuck adapter.

If you burn your drill bit's probably you have let it get hot too much... trying to push too hard, spin too fast, forcing it trying to go faster... maybe you should try pull out more often and water it a lot more often. Even if you get those rotary drills, you'll still have the problem if you do that. except it is more forgiving.

I used a $10 HDX homedepot garden sprayer when I drill harder stuff like boulders...with my sds max

 

[MushCreek]

Unless you see yourself doing more of this in the future, just rent what you need. I bought one at HF because I was building a new house out of concrete. The HF one works great, and I still use it from time to time. Although my concrete is new, the aggregate is very hard stone. Tap-Cons often snap off when I try to drive them. The SDS drill goes right through it, though.

 

[Jlbc212]

I bought a Makita SDS Plus rotary hammer several years ago to replace an older Milwaukee rotary hammer I had. I was retired when I bought it. I never thought when I bought it that I would use it as much as I have. If I had just rented one from Home Depot I would have given them at least 10 times the amount I paid for the Makita. I did rent an Italian made drill to drill a couple of 4" holes through 10" concrete.

https://www.amazon.com/dp/B00134BOYS/?tag=atomicindus08-20

 

[drivesitfar]

ALL: I love my Milwaukee hammer drill and with concrete bits up to an inch I can drill through almost any old foundation or cement wall. at least I haven't found one yet that it can't put a hole in and i live in a concrete block house.

While i'm here and SEAN is trying to attach a heater anybody have a good attachment bolt or something to attach to concrete block that they like if you can't reach the back of the block to put a bolt thru it?

 

[Roundhouse]

I thought I had the right tool for the job, but apparently not! Didn't know there was any difference between hammer drill types once they get as large as the Milwaukee one that I have. So lets say I purchase this one:

https://www.harborfreight.com/105-a...o-variable-speed-rotary-hammer-kit-63441.html

Not really going to get regular use, just every once in a while so I don't know about spending a bunch of money for a better quality brand. Would this be capable of doing the 3" hole for the exhaust port or would I still need to rent a different tool?

I would imagine that renting a tool would likely cost me $80 or so for a day, so if I can buy a decent one at twice that cost, then I would say it is worth it. So lets say under $200 what is the best bang for my dollar?

Also I see that DeWalt has 20v versions of SDS plus drills, and I am a sucker for cordless expanding my current DeWalt platform and would be willing to pay a bit more for one of those. Would that be enough of a drill or do I need to focus strictly on a corded unit? Thanks!

You won’t be drilling much concrete with a battery powered drill

 

[finn]

You won’t be drilling much concrete with a battery powered drill

Dewalt SDS plus with a Flexvolt battery did just fine drilling the anchor bolt holes for my lift installation.

 

[ConCretin]

I don't disagree with most of the comments but wanted to clarify a couple points;

SDS, SDS plus, spline drive, etc refer to the configuration of the bit and 'chuck' not the operation or power of the drill although drills using larger bits will tend to be more powerful.

A hammer drill or rotary hammer operated by hammering/pulverizing the concrete as the bit turns not actually cutting or drilling the concrete. The harder the hit the more powerful the drill.

You'll need a core bit to drill your 3" hole. This type of bit uses imbedded diamonds to abrade the concrete. You don't want any hammering action with this bit and you'll need water to cool the bit.

Finally, are you sure you aren't hitting a piece of rebar? Even the smallest drills should do better than you describe unless something is amiss.

Sorry if I've missed similar comments in previous posts.

 

[JoeMcGov]

I don't disagree with most of the comments but wanted to clarify a couple points;

SDS, SDS plus, spline drive, etc refer to the configuration of the bit and 'chuck' not the operation or power of the drill although drills using larger bits will tend to be more powerful.

A hammer drill or rotary hammer operated by hammering the concrete as the bit turns not actually cutting or drilling the concrete. The harder the hit the more powerful the drill.

You'll need a core bit to drill your 3" hole. This type of bit uses imbedded diamonds to abrade the concrete. You don't want any hammering action with this bit and you'll need water to cool the bit.

Finally, are you sure you aren't hitting a piece of rebar? Even the smallest drills should do better than you describe unless something is amiss.

Sorry if I've missed similar comments in previous posts.

Thank you Sir for getting that clarification out there. Sometimes those of us "in the know" take it for granted while our less initiated brothers here on GJ are likely saying "SDS? Super Duper Super?".

Again, SDS is how the drill bit shank is made and then held by the hammer drill so that it stays positively locked to the rotating tool.

 

[dfiler2]

Are you sure you didn't just hit a piece of rebar. A piece of steel can ruin a bit. The drill you have should do the job, IMO.

 

[Lynden]

Do you need to go through the wall with the exhaust vent? Can you run the vent up and out through the rim joist, through rafter blocking or through the roof?

 

[Farmall450]

Well, it appears that this Makita model is available for rental at my local Home Depot for $45 for the 4 hour minimum, or $64 for a day. Looks as though this particular drill goes for around $500 depending on where it is sourced from. Likely would get the job done better than purchasing a different tool for under $200?

https://www.homedepot.com/tool-truck-rental/Roto-Hammer-1-1-2/HR4010C/index.html

I would assume they have bits to rent as well at an additional cost, hopefully including the 3" hole saw. Perhaps this time around I should just go the rental route and see how it goes rather than purchase one?

Definitely not going to shell out $500 for a tool right now, and if a ~$200 tool won't be capable enough for this job and future things here and there as they come up then is renting this one my best bet?

Or do you folks know of something good in my price range that will definitely get the job done and last for a few other random projects here and there?

I would just buy the $75 HF Bauer that looks like a sawzall. Pretty good reviews, have a similar Makita that works well.

 

[Hilltopmasonry]

Dewalt SDS plus with a Flexvolt battery did just fine drilling the anchor bolt holes for my lift installation.

Yea you can probably drill 45 holes with that on battery


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[manwithtools]

You won’t be drilling much concrete with a battery powered drill

You might be surprised

I hear similar all the time about battery powered tools, but my experience is much different.

 

[Roundhouse]

You might be surprised



I hear similar all the time about battery powered tools, but my experience is much different.

I have a bunch of Ryobi tools and the batteries don’t last long at all

 

[ItsNemo]

You might be surprised

I hear similar all the time about battery powered tools, but my experience is much different.

Agreed. The bigger flexvolt stuff has shockingly good run time for cordless. I almost always grab my Dewalt cordless grinders these days when doing welding projects. I can usually go all day with a single battery on a single charge but I also don't make a mess where I have to grind boogers off for hours.

You also don't necessarily need a 3-4" core bit, you can just drill a bunch of small holes in a circle and knock out the middle. I have done this a few times to put vents through brick walls and it works well. Usually the flange will clean up any messy look but you can also just use non-shrink grout to smooth things out.

 

[rayra]

recently used a borrowed rotary hammer and was amazed at what quick work it made of an old walkway slab. Seconding keeping the bit(s) as cool as you can.

Tree roots had elevated a concrete walkway slab, raising brick pavers into a tripping hazard. I wanted to remove as little of the slab as necessary to re-level things (and excise the root), so I drilled a bunch of holes around the periphery of the portion I wanted to remove and when I hammered the exposed slab it broke to and along those holes, like a perforation. Worked well.

Drilled a lot of holes fairly quickly, with the proper tool and techniques.

 

[gemniii]

Well, it appears that this Makita model is available for rental at my local Home Depot for $45 for the 4 hour minimum, or $64 for a day. Looks as though this particular drill goes for around $500 depending on where it is sourced from. Likely would get the job done better than purchasing a different tool for under $200?

https://www.homedepot.com/tool-truck-rental/Roto-Hammer-1-1-2/HR4010C/index.html

I would assume they have bits to rent as well at an additional cost, hopefully including the 3" hole saw. Perhaps this time around I should just go the rental route and see how it goes rather than purchase one?

Definitely not going to shell out $500 for a tool right now, and if a ~$200 tool won't be capable enough for this job and future things here and there as they come up then is renting this one my best bet?

Or do you folks know of something good in my price range that will definitely get the job done and last for a few other random projects here and there?

I can rent a 15 amp "core drill" (Hilti DD130 or similar, good for a 5" hole) for $80 and the Husky diamond 3" bit for $80 from my local Sunbelt rental. Those are "1 day charges" but I can also pick up Friday afternoon, drop off Monday morning.

I can buy that same bit for about $200.

For your purposes, if rental is easy to get to and it is a one time thing, I would recommend renting the core drill/bit.

For my purposes rental is not very easy to get to and I'm needing them several times a year. I've bought a 1 9/16 SDS Max Bosch which resides with my son, a 1 1/8 SDS Bauer, which resides in Mississippi, and I'm probably going to buy a 15 amp full blown pro breaker hammer for repair of my 80' concrete driveway.

 

[seanb02]

Went to Home Depot this morning and rented a good drill. The thing was absolutely massive, a real beast to handle. I couldn't do it due to my issues with ladders and heights, I would have ended up on the floor. Just a bit heavier and more awkward than I can do when my feet are not firmly on the ground.

Anyway had another guy do the drilling part with the tool and it was all done within 20 minutes. Blew through the concrete like it wasn't even there. Rental was $86... $20 of that being the rental for the core bit, and $7 for the rental of the regular concrete bit. Nothing to complain about for sure.

Out of curiosity I looked up that model online, and it sells for $999!

https://www.homedepot.com/p/Makita-15-Amp-2-in-Corded-SDS-MAX-Concrete-Masonry-Advanced-AVT-Anti-Vibration-Technology-Rotary-Hammer-Drill-with-Hard-Case-HR5212C/205650381?cm_mmc=Shopping%7CG%7CBase%7CD25T%7C25-9_PORTABLE+POWER%7CNA%7CPLA%7C71700000034127218%7C58700003933021540%7C92700039007273729&gclid=EAIaIQobChMI-umSp6rp4AIVdSCtBh1oTAd_EAQYAiABEgJFdPD_BwE&gclsrc=aw.ds

Anyway, the shelf is up and the heater is in place. Just need to finish setting up the fuel tank outside and run the oil line and the shop should be warm again.

 

[seanb02]

And just to mention it before someone notices that my shelf appears to be not level, it is the lines in the concrete from the different levels of pours that are not level. The shelf itself actually is just about perfect.