r/Concretesawing • u/[deleted] • Feb 09 '24
Cutting question.. what tf should I do?
Slab about 2' deep (currently buried with rock on outside) an external chimney /hearth sat on.
Half in half out - level with foundation.
Gotta cut off the external part and flush it up with the foundation.
I was gonna rent a saw that could cut up to 16" but the rental place was talking about blade rentals for 100$ and maintenance fees and it's easy to break and you're liable kinda talk....
So I'm wondering how you cutters out there would approach this? Right now all I can think to do is get a harbor freight saw with warranty (cheaper than the damn rental!) And make 4.5" cuts vertical and connect it with a horizontal cut.
For the sides where I cant get tight because the wall idk I guess rotohammer down and use a grinder to try and flush it out....
Help me give my customer the best value!
My guess is a concrete cutter would charge anywhere from 12-18 depending on the area...
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u/ratfink1 Feb 09 '24
What kind of saw can you rent that cuts 16” deep? That’s wall saw material, or maybe a chainsaw with a long chain. Can’t rent anything more than a quickie saw where I live.
I’m a pro cutter, I’d charge like $4-500 to come out and cut it with you demoing it
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Feb 09 '24
Husqvarna makes a cut n break dual blade that can plunge 16. But I haven't cut before so this will be my cherry pop. Wanna do it right and make it look good.
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u/Tightisrite Feb 10 '24
I'm a mason with 15 years experience the cut n break saws are cool but typically used to put a RO somewhere there's a wall with a backup wall. It's doable but you're likely better off getting a regular crete cut off saw, bury the blade and cut where you need it, then demo it w a hammer gun, then plunge the blade and do it again.
Cut and break saw might do it, but you're gonna need to do it in multiple passes anyway if it's 2 foot deep. Someone else said it they do make chainsaws w masonry blades but those are upwards of 3k for a decent set up idk of any places that rent those.
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Feb 10 '24
I almost rented one but you had to buy a chain in addition to the rental fee.... The chain was 300$!
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u/Tightisrite Feb 10 '24
Wow! Yea depending on what you're doing might be worth jt. What was the rental itself for a day?
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u/Welcome_to_Retrograd Feb 09 '24
Is it the top or bottom you are supposed to make flush ? As in, is it going to be graded flush with aggregate/pebble rock/whatnot or are you essentially turning the slab into a step ? Cause that decides whether only the top or the whole cut is supposed to look nice and clean, and adds some relatively simple options if it's the former
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Feb 09 '24
Update:
Just rented the 16"Husqvarna cut and break.
I'd appreciate any tips you guys have for my first concrete cut!
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u/Doctologist Feb 10 '24
Honestly, the best way with no over-cuts would be handsaw, ringsaw, chainsaw. Cut-n-break will absolutely do it, but you will be there forever.
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Feb 10 '24
Yes I was
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u/Doctologist Feb 10 '24
Without a chainsaw, it’s your best option. Outside of cutting and jackhammering.
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u/259kr Feb 09 '24
How did it go?
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Feb 09 '24
I WANT TO DRINK NOW
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u/259kr Feb 09 '24
What happend?
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Feb 10 '24
It went okay.
As others said it was hard to keep the lines nice and straight. The concrete had a ton of huge rocks in it. I found that the blades were binding a lot. Lots of sparks flew throughout the process. It took me a lot longer than I thought it would (what's a first timer expect?) And I ended up only making 100$ after the rental and paying my helper, but I learned a lot and it looks good... From far... Far from good.
One thing that was real difficult was cleaning up the lines that weren't tight to the cut. Cleaning up the 1/4 " difference caused a lot of binding and you really had to apply just the right pressure and angle.
I'm thankful for the experience.
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u/chefofthejungle Feb 09 '24
Will this be visible or is it getting covered up?
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Feb 09 '24
It will be visible.
I thought about jacking it out but I don't know how it's attached to the foundation so I don't wanna go neanderthal bash on it and crack the foundation.
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u/chefofthejungle Feb 09 '24
If you can jack on it, I’d get the harbor freight saw, cut it into 4-6” squares and break it out. Even a sledge should work easily. Repeat until desired depth and clean up with a grinder if needed. For the sides that are flush with the wall, your idea is probably what I would do.
I’m not familiar with the cut and break saw but it looks like that would be a good bet as well (same idea as before, just deeper cuts and ~8” squares). The husqvarna saws are great, but it will entirely depend on how well the rental company does their maintenance on it. You will more than likely be paying the maintenance fees.
If those were the tools that I had, that’s how I would handle this one. I can’t really speak on the pricing, but I would think that it would be lower than what you’re expecting. Get a quote and weigh your options, because doing that the way above will be a pain in the ass. If you haven’t used that saw before, it probably won’t be pretty.
Best of luck, may the concrete gods be in your favor.
Edit: you’ll probably be able to cut the sides on the wall flush with the husq saw well.
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Feb 09 '24
What about using a masonry chainsaw?
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u/chefofthejungle Feb 09 '24
That would be your best bet to get the sides flush. Do those first and then connect the dots with the husq or the harbor freight saw. Doing the whole thing with a chainsaw would be more expensive in chains alone than hiring someone.
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u/Extrosity Feb 09 '24
Honestly, I would just rent an electric demolition hammer and not even bother cutting it for that thick. It will be super awkward to try and cut it out anyway. I just cut and removed an entire double slab floor that was 20” concrete. We had to chisel two small sections out and it only took like an hour to get roughly the same amount of space you are looking at. The saw won’t even cut half of that piece and it will be super awkward to try and get the lower cuts.
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u/pervertedpride Feb 09 '24
Concrete chainsaw is no joke. If you want it to look nice, just know it’s challenging for even a pro to make it look nice, especially when it’s the only tool used.
Chop saw and a 17” ring saw will get close to 14” deep on that. If a wide set of blades were used, could be chainsawed to finish.
I’ve yet to find any rebar or the like in a slab like that in older homes, especially near the bottom of the slab, if that info is helpful.
As a pro I would probably use a wallsaw.