[jayp]

I want to vent my electric clothes dryer through a cinder block foundation wall. What's the best way/tool to cut a nice round hole in it? I thought about using a 4" hole bit but I don't think it will cut concrete very well -- plus burning up the teeth on a $30 bit kinda sucks. How do you guys do it?

 

[wrangler]

this is the type of saw I like to use for cinder block. Then just pretty up the hole with trim.

 

[jayp]

hmmm

Is there some kind of a chisel or something to make it prettier? I mean, I'm all for busting a hole but I don't want some jagged-looking mess. I can always pack in new concrete around it after I'm done.

 

[Jim Hart]

You can use a 1/4" or 3/8" X 12" masonry drill bit to drill a series of holes in a 4" circle and then break out the middle with a hammer. Patch with morter after the vent pipe is installed.

 

[jayp]

yes

I was thinking of that -- sounds like the perfect solution. Thanks!

 

[woodlake]

this is the type of saw I like to use for cinder block. Then just pretty up the hole with trim.

Nice! :thumbup:

And here's the best trim available for the job. (no cutting/nailing required)

 

[Thurman]

I'm with Jim on that one. It's not that hard at all to drill, say a dozen or so holes and then knock out the chunk. I actually make my holes somewhat tight, pass through the aluminum sheet metal dryer vent and then use silicone caulk to seal it.

 

[jomama45]

Jay, how old are the block. If you have older block that are 3 core, your probaly going to hit a web, which is a pain. If newer 2 core, you should have about 6" to get your pipe thru without a web. I would recommend the mortar to patch it too, it will last forever, & nothing says "I don't care" like Great stuff. :whistling2:

 

[jayp]

haha

Totally... that's true. Yeah, I was planning on using cement patch just to give it a nice smooth look. The blocks are about 60 years old.

 

[jomama45]

Totally... that's true. Yeah, I was planning on using cement patch just to give it a nice smooth look. The blocks are about 60 years old.

Then they are probably 3 cores, which only have maybe 3-4" between the webs. You can usually verify by looking at the top of the foundation wall, assuming it's still open.

 

[Chemist1961]

Jay, as stated above examine your block and find the holllow center dimension between webs if you can. I drill 2" central vac tube acceses in these frequently and charge by the hole due to risk of core bit damage and cost of future replacement bits.

Older 3" block that I have done has tighter webs and is much harder material than the current stuff,....not fun to do by hand.:furious:

I would rent a core bit and large hammer drill or find a plumber/ electrician /HVAC guy and let him have the headache for 15 minutes of his time (with the right tools) and your cash.

Is it too big a hole to pass code if you go through the rim joist instead?