Need to remove a few Cinder blocks from foundation wall

[couch67]

I've got a home project coming up where I need to remove a few blocks from my basement wall. It is an inside wall, and not load bearing. Standard 10" blocks, hollow and not reinforced.

What would be the easiest way to bust out a few blocks in the middle of the wall (not near the top)? Cutting the opening is probably overkill, and I'll need to mortar the opening edges anyway.

I was going to start with a few masonry chisels and a 2 lb hammer, maybe start by drilling a few holes through the hollow parts but not sure if this is redundant.

(Sorry I dont have any photos - this is for a top-secret project )

 

[pcmeiners]

I was going to start with a few masonry chisels and a 2 lb hammer

One chisel, one hammer, way to go. Hammer alone would remove 80% of the block. Don't make it a major engineering project out of it, 15 minutes per block maximum.

 

[tncatadjuster]

It was way easier than I thought when I did the same type job. Eye protection and I found the third time I hit my thumb was the worst, I would stop at two.

 

[cgrutt]

I'd probably score the cut line with an angle grinder and diamond blade first. Do you have access to both sides or only one? Angle grinder will generate a ton of dust so respirator and some sort of containment strategy if you decide to go this route. A shop vac with bag and filter may help.

 

[OccupantRJ]

Air hammer chisel will eat it alive. I once rented an electric jack hammer to remove a set of brick steps. Heavy as hell. Next time I used an air hammer with a chisel tip and peeled it off layer by layer. My vote was for the latter method while sitting on a stool. Short bursts worked well. I later cut an access hole in a brick foundation with the air chisel and it worked well once again.

 

[gahrajmahal]

I'd probably score the cut line with an angle grinder and diamond blade first. Do you have access to both sides or only one? Angle grinder will generate a ton of dust so respirator and some sort of containment strategy if you decide to go this route. A shop vac with bag and filter may help.

This is probably the way I would go about it too as the cut line will be nice and straight. Two other ways to get a score line would be to use a Diamond blade in your ultrasonic saw. Will take a long time, but less dust for sure. The other is to use a hammer drill and make a series of holes in a line. You never know how hard those blocks or mortar lines will be.

 

[OccupantRJ]

I would definitely score cut the overall opening shape with a blade, then remove the center with the air chisel to retain clean edges. You can deburr sharp cut edges by rubbing with a scrap piece of the block if needed.

 

[pcmeiners]

Eye protection and I found the third time I hit my thumb was the worst, I would stop at two.

Personally I would not plan on hitting my thumb the first time.

 

[CraigStu]

I like the idea of drilling rows of holes. Since you are inside the foundation I think drilling will create less dust especially since most drills have easily controlled speed. You can experiment w/ how close they need to be to get an edge finish you can mortar over.

 

[mike93lx]

Great reason to buy an sds. No thumbs in the line of fire.

I like the grinder idea, but probably wouldn't do it myself. I'd start at the middle of the block and work my way our, using a chisel on my sds or demo hammer, depending on clearance and positioning, and have a vacuum on hand

 

[larry4406]

Masonry blade in an old skil saw. Pump sprayer to dampen wall periodically and a shop vac.

I have an old saw for this purpose I use to cut basement slabs.

 

[The Cobbler]

if you're going to the mortar joints, a 5lb sledge with several good whacks in the center of the block will get some cracks going. then work away at it . won't need a chisel , maybe just to clean any residual mortar left .
I wouldn't use a saw or anything else if that was my job

 

[finn]

I used a 14” gas Makita demo saw with a diamond blade. Didn’t use the water dust suppressor, but I should have.

The new demo saws are mostly electric, which is an improvement. I think even HF has one. Box stores rent them.

Hammer and masonry chisel will work, but it’s not as much fun as buying a new tool that you’ll use once in your lifetime.

 

[Pen & Wrench]

Another vote for an air chisel. I did that and it worked like a charm when I had to take a few blocks out of a block basement wall.

 

[couch67]

Thanks for all the replies. Hope to get to this later in the weekend (after some front end work on the DD). Will post results

 

[Old tool guy]

If the opening is going to be fairly wide, after you remove the mortar slip a piece of 1/4” angle iron in the gap to act as a lintel.

 

[BurtEggley]

interesting question. I would think the answer would be dependent on whether they are really hollow or filled in part or full with concrete and rebar

 

[pcmeiners]

I wouldn't use a saw or anything else if that was my job

Some people love making work and dust, great for silicosis of the lungs and for those who have a fetish for vacuum cleaning.

 

[mike93lx]

Some people love making work and dust, great for silicosis of the lungs and for those how have a fetish for vacuum cleaning.

You know the rules on kink shaming

 

[pcmeiners]

You know the rules on kink shaming

Was not shaming anyone just encouraging them.

 

[couch67]

Well that was easy.... much easier than I had built up the job in my head!

The hammer did about 95% of the job in about 30 minutes. A chisel to clean up some of the edges and remove mortar joints left in the opening. Didnt hit my thumb once (was thinking about your post @tncatadjuster !)

Took longer to clean up the mess afterwards. Now to find a place to get rid of a rubbermaid full of concrete chunks.

Thanks all for the great tips, was putting this job off for too long because I wasnt sure what I was getting into.

 

[mike93lx]

Took longer to clean up the mess afterwards. Now to find a place to get rid of a rubbermaid full of concrete chunks.

The highway?

 

[NUTTSGT]

Did you take out 2 blocks that are end to end, like a 8"x32" hole ? If so, I hope these are at the top of the wall under the floor joists and nothing else above them.

If they are in the middle of the wall, you going to need something to support the block above the hole.


As far as getting rid of the broken out block, make sure the pieces are broken in smaller pieces to make it easier, depending on what you have for trash pick up. I'd put some in a cardboard box every week and get it go out to the curb. Like I said, depends what you have for trash service.

 

[couch67]

Thanks @NUTTSGT. The hole is two courses down from the top of the wall. The hole ended up being about 22" wide and 16" high.
I do have some angle that I'll install when patching up the opening to finish size.