# Method and cost to core a dryer vent in concrete?



## bgrimes (Aug 31, 2009)

Hi. I'm new to this forum, but am a seasoned DIY renovator. After 18 months of gutting and rebuilding our house, I'm stumped by one thing right now: Installing a dryer vent. 

Are there tips on how to handle coring out the hole? I'm looking at needing to core through about 10 inches of concrete for this vent, and I'm not sure what to get to do it. I'm seriously lost on the proper tools for this one. I don't need a jack hammer...but some serious hammer drill I suppose? I've seen bits online that are 4" coring bits going for $150. Any chance those can be rented? This has to be a fairly standard need, my problem is that this isn't some wood sided house, we live in an old row house in Philadelphia and the front is poured concrete.

Any tips would be greatly appreciated.

- Bryan


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## Thurman (Feb 9, 2009)

bgrimes- -Please read an understand this carefully, as I am trying to help you and to prevent you from getting hurt. Basically your are asking if a 4" core drill and drilling machine can be rented? YES, is the answer, in my area at least. Therein lies the problem, they will rent the equipment to anyone with now questions asked if the renter has any knowledge of how to use this equipment. I, Me, have used core drills in my years of Industrial Maintenance to drill holes in concrete floors up to 12" thick and walls up to 12" thick. Does that make me an expert- -NO. Just experienced. Using a core drill to drill a 4" hole through a 10" wall is NOT a job for a DIY or novice to say the least. This euipment is heavy and requires experience to drill vertically. I would suggest to you, that you find a good hammer drill, and a 3/8" x twelve inch (12") long masonry bit to rent for this. Mark the hole where you need it to be and start drilling holes around the perimeter of the hole you marked as close together as you can. It's going to be a long tedious job, invite some friends to help. Once you have all of these holes drilled it should be just a matter of hitting the plug of concrete with a good sized sledge hammer a few time to knock it out. BUT- then again, it would not surprise me if there were re-bar in the concrete wall to deal with. If you can bust out the concrete you can cut the re-bar with a hacksaw. Not a good solution, but a safer one. Good Luck, David


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## bgrimes (Aug 31, 2009)

Thurman, thanks for the reply. I share your safety concerns, which is why this has been a project I've been trying to research for a month or so before doing anything. Obviously one would like to avoid having to drill 8+ holes and then chiseling/smashing out the middle, but I'm thinking that might be what does it. We've debated calling a couple of concrete contractors for estimates, but I was curious about the possibility of just coring out the hole and being done with it.

Thanks again. I just might have to call up some buddies and supply the beer...

- Bryan


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## Aggie67 (Dec 20, 2008)

If we're in a chemical plant with 12" of brick, we use one of our Hilti TE-56's with a cupped core bit. When you bottom out, we whack the plug out with a small sledge, then keep going. But it tends to be a sloppy hole (chips around the edge). 

If we're coring through concrete walls for piping and what not and we want a quick clean hole, there really is no other choice. We have a wet coring rig that we anchor to the wall. Do a Google image search for that term, and you'll see what you need. I don't like freehanding it because a lot of times the hole doesn't get cored straight when you do that. Most rigs have outriggers that you anchor to the wall when doing horizontal holes. 

Someone may tell you that a hammer drill core bit will get you through rebar with a rebar cutting bit, but you'll destroy the bit. A new bit should last for 30 holes or so.

In this case you may want to hire a coring guy. I have a guy we go to that all he does is coring and cutting. Pretty reasonable. The last job he did for us was 82 holes, and it worked out to be about $28 a hole. I'm sure for just one hole you'll probably get banged for a few hours, but no one is going to travel for just one hole for $28. But it might be cheaper than buying a bit and renting a coring rig. You'd have to check and compare. Also, most places in NJ rent rigs with bits, but they measure the teeth before and after and charge you for what you take off the teeth.


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## PaliBob (Jun 11, 2008)

Bryan, I'm with Thurman on not going the rental route. I always called our local Concrete Coring outfit here on the LA West side. I have found very few concrete contractors here that core their own jobs at those large sizes

How about calling Americore, they are over in Lansdown, only 10 miles from you. They could zip over and finish the job in an hour, at least the way that I see it.

http://maps.google.com/maps?hl=en&r...L-uCUDg&sa=X&oi=local_group&ct=image&resnum=1

my wife grew up in Olney and we still have family in the NE


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## stadry (Jun 20, 2009)

kind of difficult to dri-core thru 12" especially if you hit steel,,, wet coring's ok BUT you need to anchor the base to the wall,,, if brick, its best to ' thru-bolt ' altho attaching a surface plate w/anchors then using a vac base works ok.

ag, we did some coring yrs ago in ny-nj-ct-pa - holes, inc, of paterson - might've even done some work for you.

don't bother w/carbide bits on steel,,, had 10K+ 1 1/8" holes to drill down at colts neck,,, they ruined many MANY bits before we set up a 3drill-3 speed rig,,, segment useage charge's normal - if none, they've built it into the rental $


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## Scuba_Dave (Jan 16, 2009)

I had to cut thru a cement wall for a drainage pipe for my sump when the addition went in
There was dirt on both sides, & once completed the pipe would be covered with dirt
So I wasn't concerned with looks
I used a pick, hammer drill, sledge hammer & a chisel "gun" (?) powered by air compressor
It wasn't as bad as I thought, But still a royal PIA


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## paul100 (Aug 29, 2009)

bgrimes said:


> Hi. I'm new to this forum, but am a seasoned DIY renovator. After 18 months of gutting and rebuilding our house, I'm stumped by one thing right now: Installing a dryer vent.
> 
> Are there tips on how to handle coring out the hole? I'm looking at needing to core through about 10 inches of concrete for this vent, and I'm not sure what to get to do it. I'm seriously lost on the proper tools for this one. I don't need a jack hammer...but some serious hammer drill I suppose? I've seen bits online that are 4" coring bits going for $150. Any chance those can be rented? This has to be a fairly standard need, my problem is that this isn't some wood sided house, we live in an old row house in Philadelphia and the front is poured concrete.
> 
> ...


 
I live in Philly and i know the type of house. It should be brink on top of the concrete. Is there no way to get the vent to the brick portion. Its a lot easier to work with brick then concrete.. Is there no way to get the vent to a window?


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## bgrimes (Aug 31, 2009)

paul100 said:


> I live in Philly and i know the type of house. It should be brink on top of the concrete. Is there no way to get the vent to the brick portion. Its a lot easier to work with brick then concrete.. Is there no way to get the vent to a window?


So what we have is a two story bay on the front of our house..and I'm looking to go to the side of it. From basement side it's parged concrete, and from the outside it looks like concrete...but it may well be a couple layers of stucco over brick which would make sense actually. I know when Comcast was out a couple years ago for cable, the guy had no problem drilling the hole he needed, but this is a different story.

I've added a picture of the front for you to get an idea. I'm looking to do this on the other side of the bay, but that's not here nor there.









if the pic doesn't show: http://bp2.blogger.com/_SuxBapT3pv8/SEM9n4ASY2I/AAAAAAAAAE8/vAt11IQHZI0/s1600-h/Door2.jpg

It may be that the entire bay is brick throughout (which I can't believe I haven't looked into yet...doh!), but I'm pretty sure they reinforced the inside with concrete about 40 years ago.

If it is all brick, does this make the task easier? I've drilled into brick many times, but nothing this big.

Thanks for all of the replies.
- Bryan


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## jogr (Jul 24, 2007)

Is there a wood rim joist supporting that bay? Rim joists are great locations to put dryer ducts.


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## Paragon (Jun 14, 2009)

Yeah I too am wondering if the dryer vent will go through a rim joist right about there but on the other side lol

Good luck let us know how it goes!

Be safe!


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## Gary in WA (Mar 11, 2009)

Before you cut your hole, you may want to check your local Building Department. If under the IRC, it's no problem. Any other code may not work. Duct termination: Minimum 3' from other building openings....{504.5} 

You probably know to support it every 10', needs to be smooth metal inside, no screws, foil tape works fine (on each segment of elbow too), 25' max. - 2' per 45*, 5' per 90*, back-draft damper, no screens. 

Be safe, G


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## Scuba_Dave (Jan 16, 2009)

My vent goes OUT an existing window :laughing:


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## bgrimes (Aug 31, 2009)

Paragon said:


> View attachment 13170
> 
> 
> Yeah I too am wondering if the dryer vent will go through a rim joist right about there but on the other side lol
> ...


Interesting idea on the rim joist, hadn't thought of it. Tonight I'll look closer in the basement and take a couple of pictures. I'm not sure that the framing in that bay is quite like that, but hey, who knows.

Cheers!
Bryan


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