Question about drilling holes in concrete/brick for conduit

[lukerah123]

Hey everyone,

I am new here and recently discovered this forum. I was wondering if I can get opinions about drilling holes through concrete/brick in buildings.

I have noticed that on some jobs, they use coring drills with diamond wet bits to core large holes in concrete for conduit runs. I understand that they are probably more effective for going through rebar and larger holes.

If I wanted to a run 3/4" conduit through a concrete wall to reach the other side, what options do I have? I was thinking a regular sds plus hammer/rotary drill can accomplish this due to needing a smaller hole.

What size hole, drill, bit, and strategy do you recommend for this? (if possible)

Thank you

 

[tom baker]

Welcome to the forum.
A rotohammer will work, but will blow out a big chunk on the other side. About 20 years ago we started using hand held core drills, faster than a rotor hammer. Larger holes we used a stand with core drill
If no rebar and yon can patch the blowout, use a 1 1/2” rotorhammer

 

[Hv&Lv]

Welcome to the forum.
A rotohammer will work, but will blow out a big chunk on the other side. About 20 years ago we started using hand held core drills, faster than a rotor hammer. Larger holes we used a stand with core drill
If no rebar and yon can patch the blowout, use a 1 1/2” rotorhammer

I stop blowout by using a long 1/4 SDS bit in my drill.
My bits are 24” long..
Start drilling with the 3/4” or 1” bit, stop about 3” from the edge of the wall.
Change to 1/4 bit, drill through easy. Don’t push it through with all your strength.
Go to other side with the original bit and finish the hole

 

[Strathead]

I stop blowout by using a long 1/4 SDS bit in my drill.
My bits are 24” long..
Start drilling with the 3/4” or 1” bit, stop about 3” from the edge of the wall.
Change to 1/4 bit, drill through easy. Don’t push it through with all your strength.
Go to other side with the original bit and finish the hole

In my experience, that minimizes the blowout, not eliminates It all depends on the concrete, and luck. For example, it the is a rock near the end, you can still blow out a plug much bigger than a 3/4" conduit hole.

 

[Hv&Lv]

In my experience, that minimizes the blowout, not eliminates It all depends on the concrete, and luck. For example, it the is a rock near the end, you can still blow out a plug much bigger than a 3/4" conduit hole.

True. If there is a rock and you center it, not much you can do but patch. Granite or river rock aggregate would be the worst IMO..
Around here they use a slate aggregate
But that method eliminates it most of the time.

 

[Jpflex]

I

Hey everyone,

I am new here and recently discovered this forum. I was wondering if I can get opinions about drilling holes through concrete/brick in buildings.

I have noticed that on some jobs, they use coring drills with diamond wet bits to core large holes in concrete for conduit runs. I understand that they are probably more effective for going through rebar and larger holes.

If I wanted to a run 3/4" conduit through a concrete wall to reach the other side, what options do I have? I was thinking a regular sds plus hammer/rotary drill can accomplish this due to needing a smaller hole.

What size hole, drill, bit, and strategy do you recommend for this? (if possible)

Thank you

never had to drill into concrete yet but I was always wondering if I wanted to run EMT along concrete and secure with hole straps would I use a masonry bit to concrete then insert a plastic anchor in hole to support bolt and hole strap similar to Sheetrock or drywall? Or how is this done proper? Thanks

 

[retirede]

I

never had to drill into concrete yet but I was always wondering if I wanted to run EMT along concrete and secure with hole straps would I use a masonry bit to concrete then insert a plastic anchor in hole to support bolt and hole strap similar to Sheetrock or drywall? Or how is this done proper? Thanks

Lots of options. Lead anchors, RedHeads, TapCons……Much comes down to personal preference. Anchors for strapping to a wall aren’t nearly as critical as strapping to a ceiling because he forces are shear rather than pull-out.

 

[cadpoint]

My best thing I've ever seen was a concrete service show up and walk out of the truck with a 4" hole saw
(probably diamond blade) and proceed to start and finish a coring through a red brick wall with only gloves on.

It was crazy to watch that he was so cavalier about it but did the job!

 

[mtnelect]

This is what I use.

 

[Hv&Lv]

My best thing I've ever seen was a concrete service show up and walk out of the truck with a 4" hole saw
(probably diamond blade) and proceed to start and finish a coring through a red brick wall with only gloves on.

It was crazy to watch that he was so cavalier about it but did the job!

I bet that was a sight to quickly turn away from if all he had on was gloves…



I have all sizes dry core bits that fit on a grinder
from 1 1/4 to 4.5”
Got a large box at an auction years ago for $200 probably 20 bits total

Dry Diamond Core Drill Bits

Dry diamond core drill bits designed for drilling soft brick, masonry, and concrete block. 5/8" - 11 Arbor, 9.5" drilling depth, can be used both wet and dry

www.ediamondtools.com

 

[tom baker]

I stop blowout by using a long 1/4 SDS bit in my drill.
My bits are 24” long..
Start drilling with the 3/4” or 1” bit, stop about 3” from the edge of the wall.
Change to 1/4 bit, drill through easy. Don’t push it through with all your strength.
Go to other side with the original bit and finish the hole

I found my larger bit would get stuck in the smaller hole. But not all bits are equal for drilling, the Hilti bits with the X bit drill best and can sometimes go thru rebar

 

[LarryFine]

My best thing I've ever seen was a concrete service show up and walk out of the truck with a 4" hole saw
(probably diamond blade) and proceed to start and finish a coring through a red brick wall with only gloves on.

It was crazy to watch that he was so cavalier about it but did the job!

I did a 6" hole for an exhaust duct through four courses of old, old red brick with my Bosch SDS-Max rotary hammer turning a rented core bit. It left the hole surprisingly smooth.

 

[Hv&Lv]

I found my larger bit would get stuck in the smaller hole. But not all bits are equal for drilling, the Hilti bits with the X bit drill best and can sometimes go thru rebar

Exactly!
that’s what mine are.
Yes, they are a little higher, but I’ve had mine for 15 years and they have drilled many holes

 

[Hv&Lv]

I did a 6" hole for an exhaust duct through four courses of old, old red brick with my Bosch SDS-Max rotary hammer turning a rented core bit. It left the hole surprisingly smooth.

That’s the way..

I despise to see an HVAC guy using a star bit on a brick home beating a hole out. Then they have to fab up a cover big enough to cover their crappy hole