PVC vent pipe holes through concrete block + brick

[FastKat]

I am contemplating installing a high efficiency gas water heater (I currently have an electric tank) and I have no idea how to make a nice clean hole through my basement wall. It is concrete block + there is brick on the outside. I am sure this is a very regular thing... How do you do it?

 

[MFolks]

How big in diameter,how deep? Ask around for concrete drilling,or the rental places,water cooled drills might do it,but I've no idea how much. Like a giant hole saw,with either carbide or diamond cutting edges.

 

[Ric in Richmond]

I used hammer and masonry chisel.....tap tap tap tap tap...one like this....

 

[Gummi Bear]

Either core it yourself (rent the tool and bit) or hire it out.

I think the minimum charge from the coring company I use is $250

A clean hole is worth the expense. You can seal up the penetration once you get the pipe through.



I went to the woods because I wished to live deliberately...

Henry David Thoreau

 

[ddawg16]

I am contemplating installing a high efficiency gas water heater (I currently have an electric tank) and I have no idea how to make a nice clean hole through my basement wall. It is concrete block + there is brick on the outside. I am sure this is a very regular thing... How do you do it?

The brick on the outside is going to be your biggest issue.

I really doubt you will find a masonry hole saw that big.

You need to find out what the requirements are for venting. If it's a high eff. water heater, it's most likely the condensing type which means you can get by with PVC for the vent. But...if it was me, I'd plan for worse case....assume 4" B-vent (double walled). B-Vent can be within 1" of combustionable materials. Cinder block is NOT combustionable.....so it can be a snug fit.

But if it was me...I'd make it a 6" hole...line it with a PVC or steel sleeve and use fireproof insulation to fill in the void between the pipe and sleeve.

For the hole...Start small and use something like what Ric suggested to enlarge it to size. Your are going to end up with a fairly rough hole...especially on the brick side. You can hide the rough edges with a flange to make it look 'pretty'.

 

[fasteddie]

Cement block and brick are both fairly soft material. Rotary hammer or 1/2" hammer drill with a quality, long masonry bit will go through easily. Drill a series of holes around the circle perimeter and break the web out with a chisel.

 

[FastKat]

Thanks for the info guys. I don't know the hole size yet as I have not settled on a unit. The ones I am looking at use either two regular PVC pipes or a single concentric pipe setup which I imagine would be around 4 to 5".

I don't think I want to hire it out. The chisel looks merciful... I don't think I've ever seen one with a hand guard! I thought maybe I could just buy a special hole saw but drilling the perimeter and tapping out the center seems like a good idea, too. I can also look to rent a machine.

 

[The Cobbler]

find out the hole size(s) you need, go to a rental yard & rent a core drill and rotary drill .
send a pilot hole thru the wall from inside so you don't hit any floor joists ( I use a long 3/8 carbide bit for this)
use the core drill from outside . as the bit hits bottom, remove it and break out the core so you can drill deeper. repeat till thru . don't try to match the size exact as wandering will probably occur with the bit and the hole wont be perfect, it will cause for a tight or impossible fit , go at least 1/4" larger on the hole.

 

[yeldogt]

Typically you would use a masonry bit and make a series of holes after drilling one (larger) in the center to get the placement. Mark out the vent hole size using the first as a guide outside -- as you drill the brick will crack away. The whole point is to try and lay it out correctly so it falls on the brick correctly and is tight to the pipe outside. Inside will not matter.

The concentric kits are a nice way to go as only one pipe -- unfortunately, they don't have any type of trim ring to hide the hole. You would most likely need to cover the gap with some mortar to make it all pretty. Mortar the interior .

some the WH's are very small

 

[FastKat]

Thanks for the info guys. I watched some YouTube videos and I think renting the core drill is the way to go. I can use either two 3" PVC vents or a single 5" (I think) concentric vent. I'm not sure if there is a benefit to either besides price and number of holes to drill. The unit is tankless so it has a pretty substantial demand for gas and therefore ventilation.

 

[75gmck25]

I've done both (drilling multiple holes and using a core drill), and I would definitely rent a core drill for large holes. The large drills are heavy, so you may need help keeping it level at first, but it makes extremely quick work of going through the brick.

I also had to put a couple holes for 2" conduit (needed about a 2 3/8" hole) through the brick and block of my garage, and I just bought a coring bit and arbor from Home Depot and used my corded hammer drill. It actually worked almost as well as the larger drill I had rented.

Bruce

 

[Jackfre]

If it is the new Rinnai Sensei your choice is the two pvc lines or the 2/4" concentric. I'd go with the concentric. Only one hole and it trims out much better. renting a core drill would be the cleanest, fastest, best. Make sure the damned thing is tied down. Otherwise, get a root-hammer and drill the circumference of the hole and drive out the core. It is joyful work.

 

[bobbyjean]

Cement block and brick are both fairly soft material. Rotary hammer or 1/2" hammer drill with a quality, long masonry bit will go through easily. Drill a series of holes around the circle perimeter and break the web out with a chisel.

i have done it this way many time's...take's awhile but it gives good results,the coring bit works well to.....but i wouldnt use it to work a hole above my shoulders....may need aflac

 

[yeldogt]

Drilling a big hole with a core drill is not the easiest -- be careful with the tool as it can pull your arm off. Going through brick with simple impact bits is easy -- the block can be more difficult depending on type and if filled with concrete.

I have a large hitachi max impact -- two of my places are block and bring .. so it's had some use. Around me it's $400 for a core driller to show up