# What is the Best Way to Cut a Concrete Block Wall?



## princelake (Feb 19, 2012)

i was going to say chain saw, score with the an angle grinder with a diamond wheel and a sledge hammer?


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## joecaption (Nov 30, 2011)

An angle grinder will not cut deep enough.
Rent a Cut off saw with a diamond blade.
http://www.stihlusa.com/products/cut-off-machines/accessories/diamond-wheels/

Have you checked the Home Depot rental desk for a chainsaw?

PS There is no easy, dust free way to do this job.


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## BeachBum2 (Aug 16, 2011)

I've used one of those, but don't want to wrestle with it.
Haven't checked Home Depot - good idea.

How about a Sawzall? Am I crazy to think about one of those?


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## joecaption (Nov 30, 2011)

Not going to happen, A carbide blade might last a min. cutting concrete.


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## sixeightten (Feb 10, 2009)

A grinder can work if you have access to both sides. It is much slower, and still dusty though. Never heard of a sawzall doing that.


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## bassheadjohn (Aug 12, 2012)

*Diamond blade*

I have cut a few blocks on limited resources. Diamond blades seem to be the only answer. Sawzall isn't going to cut it. For the amount of money you put in blades you would be better off buying a saw. I picked up a 7 1/4 diamond blade at a big box store for around 20-30 bucks a few years back. Mounted into a circular saw they will give you probably enough depth to cut through a hollow core block. Make multiple passes, making shallow cuts. Most concrete will break once scored. Not safely, but the same 7 1/4 blade can mount to most angle grinders too. If you do that you have been warned. They are unstable and you won't be using any guards. Regardless whatever diamond blade you use you will have a dust mess for sure. If you are concerned about dust put up some plastic to minimize the area dust travels. Maybe even a box fan in a window. I recently cut through brick veneer and left the interior wall intact prior to cutting. This cut back a lot of the dust the accumulated inside the house.

Lastly. When I cut that brick veneer I used a 12 saw. The depth of the cut was only about 3.5-4 inches. If you do get your hands on one take it slow. Those saws have a lot of power and a little twist and that saw will want to kick and jump back at you.


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## BeachBum2 (Aug 16, 2011)

I have watched several videos on the internet where they were demonstrating the use of a water cooled chain saw. It worked great, but so far, I haven't found one I can rent. That's where I thought of the Sawzall - as I own one of them. 

I've used a 12" circular saw one a brick wall once... not the best as it doesn't go deep enough to make a clean cut.


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## md2lgyk (Jan 6, 2009)

I once had to remove a non-load-bearing CMU wall in the basement of a 1950's house I owned. Very strange situation - the wall had to be original because the bottom course was embedded in the concrete floor. But it ran parallel to the floor joists and obviously wasn't supporting anything.

I got it down quite easily without any kind of saw. All I used was a brick chisel and a driller's hammer. I had to break just one block to get it out. After that, with space to move, I rapped on the mortar joints a few times to loosen them and all the other blocks came out whole.


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## BeachBum2 (Aug 16, 2011)

That's a good point, although I have one small section that I do need to "cut" so it looks clean... the rest could fall if it would. In that area, a chainsaw would be the best, I think.


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## BeachBum2 (Aug 16, 2011)

Ok... I found a rental ICS 680GC chainsaw with diamond blade. Same unit as the videos on YouTube.

Has anyone any experience using one of these water cooled chain saws on cinder block? Any "tips" would be greatly appreciated!


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## Canarywood1 (May 5, 2012)

I have 2 headers to cut that are about 5' wide and one header about 3'wide.

When you say "headers" do you mean lintels?


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## BeachBum2 (Aug 16, 2011)

I guess you could call them lintels, although they are not solid filled blocks.

The 5' ones are above the windows.
The 3' one is above a door.
Each is one block deep.


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## Evstarr (Nov 15, 2011)

You are adding windows and a door to this wall? You need to cut the openings for above items? 

You need to add the appropriate lintels after you make the holes. 

Be careful, when you cut out the lower blocks, the single row of block that you intend to leave in place may choose not to cooperate with your plan.


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## BeachBum2 (Aug 16, 2011)

Thanks very much.
I'm taking everything out and installing a steel I beam, then a 15' sliding door system. I'll take everything out, down to the foundation and then pour a new 2.5" sill. I thought it would be better to remove all the CMU (not leave 2.5") as the last 2.5" might not be as solid as I'd like. It's easy to frame and pour this 2.5".

I have one larger area to remove, between one of the 5' windows and the 3' door. That wall section is about 7.5' tall and 8-10' wide. I'n not sure how many cuts it will need to get out of there. It looks like these saw chains are good for 40-80' of cutting. There is a big difference between 40 & 80' though!


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## Canarywood1 (May 5, 2012)

BeachBum2 said:


> I guess you could call them lintels, although they are not solid filled blocks.
> 
> The 5' ones are above the windows.
> The 3' one is above a door.
> ...


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## BeachBum2 (Aug 16, 2011)

They were poured in place (cinder blocks. I drilled a number of holes in them and never hit what would feel like poured concrete, so I'm not sure if they are even poured at all. The place was built in 1964, before all the earthquake codes.


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## Canarywood1 (May 5, 2012)

BeachBum2 said:


> They were poured in place (cinder blocks. I drilled a number of holes in them and never hit what would feel like poured concrete, so I'm not sure if they are even poured at all. The place was built in 1964, before all the earthquake codes.


 
I don't think we're on the same page here,you would be able to tell a poured in place lintel,as opposed to a precast one and you say they are cmu's,at any rate be very careful when you start cutting,and have a planned escape route in mind. Good luck.


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## princelake (Feb 19, 2012)

when you use the chainsaw and hooked it up to the garden hose wear a rain suit, let the saw do the cutting and dont jam the chain, they are pricey.


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## bassheadjohn (Aug 12, 2012)

*Using the big saw*

Just a little suggestion to get you mental prepared. If you rent that and have a run at that wall, as I mentioned before, that saw is a wild beast to tame. Once that blade gets moving it can be compared to a gyroscope. It will spin true and steady. If you turn the saw while the blade is spinning the saw will want to twist on you. If you turn a little during a cut look out for a kickback. I would suggest going at it tapping on the trigger as you cut until you get comfortable. Just take your time. Those videos are mostly experienced users and they make it look easy. Those saws are heavy and cumbersome but in this case the right tool for the job.


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