How to Cut Basement Floor (And Stop Concrete Dust)

In this video I show you how to cut a basement floor and control the concrete dust.
0:00 How to Cut a Basement Floor
0:50 Two Ways the Project Can Go Wrong
2:58 Skilsaw Medusaw
3:31 What Blades to Use to Cut Concrete
3:57 Bauer Demo Hammer
4:50 Why Cut Concrete First?
5:30 Trenching Shovel
5:40 What to Use For Drain Pipe (Sink, Toilet, Shower)
6:16 What Fittings to Use
8:08 How to Lay Out Basement Bathroom
9:13 How to Patch Basement Floor Concrete
The main tools I used:
Skilsaw Medusaw: amzn.to/37ybchV
Bosch Segmented Diamond Blade: amzn.to/3ohLjIR
Ridgid Wet Vac: amzn.to/34oqqEe
Bauer Demo Hammer: amzn.to/2TjhKbW
Ridgid Concrete Mixer: amzn.to/3kqAH8c
For more photos from this project check out:
notwaitingtolive.com/how-to-c...
#basementbathroom #howtocutconcreteslab #notwaitingtolive

[@jwb1227]

Thank you for this video. I have watched dozens of "How to" and other plumbing design/layout videos and very few of them start off or even discuss at all the importance of *Assessing the current state of existing plumbing* prior to busting up concrete. The part about *how much room is there for the 1/4" drop per foot* at the beginning of your video is SO CRITICAL and not a lot of DIY people know this (or realize in the middle of the project).

[@lisajohnson6351]

I’ve found this video very helpful on several aspects. Thank you! 😊

[@sambrant1573]

Great video man!! Keep this up, brother!!

[@Dani-ladyy]

great vid thank you some tips i didnt think of before i start my project

[@richardbowman8193]

Ive been mixing with a milwaukee Hole-Hog for about 25 years for concrete and drywall mud mixing. It will not die

[@southparklion]

I used a saw and there are cross-marks on the end of the cut. How should I fill them?

[@user-iu1pw7dh3z]

How much dust did the demo hammer create? Did you soak the floor or do you have any advice for reducing dust with the demo hammer? Would a lighter duty demo hammer create less dust due to less power or would lighter duty hammer create more dust because it would be smaller fragments? Also, I'm trying to remove 100 sq ft from my my basement slab which is about 4 inches thick, if I only score the area 2 inches with the medusaw, do you suspect the demo hammer might cause cracks beyond the scored demo area?

[@laurenharper1510]

This helped me so much! Did you cut the concrete completely all the way down to the dirt or did you kind of score it in the shape of a square?

[@mgherter]

A 7 inch saw blade likely won't go through the entire slab. You score it and it makes the jack hammer mich easier. A sledge is also an option but that SUCKS. Rent a jackhammer.

[@garycarnivale4706]

Do you think that saw could be used to make a vertical cut? I need to cut a 1/2" x 1/2" slot in a concrete door opening.

[@notwaitingtolive]

Yes absolutely. It has great precision and a mechanical arm that can swing out in front of the saw to help you with leading lines.. Cuts up to 2” deep. Guys use it to cut expansion joints in concrete.

[@Matt-hw6tm]

Do you mind sharing what this would cost to hire out? I have a broken pipe from the basement shower/sink to the main line (3' away from shower). Thought of renting the equipment and DIYing, but curious what someone would charge. I'd probably do the concrete finishing and haul away on my own to save some cost

[@Mj-th7md]

It will cost you about $2000 - $5000 USD

[@3613jeremy]

Another option I've been seeing for existing pipe repair is some kinda snake sock they can shove in the pipe that lines the inner wall and hardens creating a new pipe definitely looks interesting

[@MikeHewitt]

6 1/2" bathroom?

[@danceman23]

Can I ask about venting? Where did that go? I'm looking at doing a similar project

[@bradwhitham4115]

The rule is condensed to "Always allow for air behind the water". A 3" common drain of less than five points of use is well served by a 1-1/2" common vent stack in most circumstances (2" if a 1-1/2" clothes washing machine drain will also be served by the intended branch). Most local codes require the vent to be located upstream from the first drain connection in the common branch line (in this case, that looks to be the the corner shower). In the above video it looks as though he cheated the vertical vent line downstream a bit to between the corner shower and the other drain connections. This would not a big deal to me as a DIY project in my own house. Depending on how strict an inspector is, that type of vent stack placement could possibly cause compliance problems down the road. Note, just as important for proper venting is an adequate slope in all the branch and main drain lines. This helps prevent backwash from high volume dosing (toilets, washing machines, etc.) causing temporary hydraulic damming of the vent or other drains and also possible sludge buildup over time. Effluent needs to move without being slowed down to keep the lines clear and clean

[@andrewprocyk]

What is the depth of the score line you made? The medusa can cut up to 2 inches deep so just wondering what the blade depth was at? Thanks

[@notwaitingtolive]

The full 2". I've also used this saw since making this video to bust open another concrete floor. It works great. If you give the area a good strong whack with a sledgehammer you can break up the concrete faster than with the demo hammer. But you may still need the demo hammer at times.

[@theobserver9131]

6 1/2" x 6 1/2" bathroom, that's absolutely cavernous if you are a mouse! Lol.

[@abdulelkhatib2674]

I did a little trench in my shop about 6ft long 2 inches wide and scoring the concrete is completely worth it. And it still chipped out on the edges so be careful.

[@notwaitingtolive]

For the trenches I’ve done since this video I still use the concrete saw to score the edge but I also use a 12 lb sledge to break up the concrete. I find that a good hard whack with the sledge works faster than the hammer drill at breaking up the slab. Although I still use the hammer drill as needed for small parts of the job.

[@andrewclark7686]

Did you have to do any treatment to the edges of the trench before pouring concrete?

[@notwaitingtolive]

No. Is your concern separation of the new pour from the existing slab? After the patch which had some thicker aggregate I did use a fine leveling compound to smooth over the joint between the existing floor and patch.

[@andrewclark7686]

Ah ok. Yeah my concern is separation as I have a trench spanning 2/3 of my basement where I'm replacing the cast iron. I've been looking at a few different how-to guides as I've never worked with concrete.

[@notwaitingtolive]

@@andrewclark7686 the concrete slab in the basement is most commonly ~2”. You can use a hammer drill (like this amzn.to/3qfS7Ig) to drill a few inches into the center of the existing slab. Then pound in 3/8 inch rebar into the hole you just drilled out (using a 4lb hammer amzn.to/3fSJjmF) such that the remaining length of the rebar covers your open trench. You can then cover that exposed rebar with a wire mesh and pour your patch (you can commonly buy the rebar and mesh at Home Depot). This will bond the new pour with the old. I’ve used this technique to pour a new driveway extension to an old driveway and keep the slabs bonded and level to each other.

[@andrewclark7686]

@@notwaitingtolive I've read about that technique as well but was kinda thinking it was overkill. My slab is 2" and that doesn't leave me a ton of meat for inserting any rebar/mesh. Also, I'm kinda thinking that since it's below grade it won't be subject to the temp swings that say a driveway would. My basement is usually 55ish in the winter and maaybe 65-70 in the summer.

[@notwaitingtolive]

@@andrewclark7686I agree. Probably overkill. The slab in this video was 2” as well. I feel confident leaving the patch on its own. If you decide to paint the floor to hide the patch I strongly recommend oil based paint which will last much longer than water based paint (even if it says it’s water based floor paint, it’s just not as resilient as oil based paint).

[@ianmiddleton1877]

6 1/2 inch bathroom is pretty small, 6 1/2 feet I guess.

[@PARKERBROTHERSPLUMBING]

2" of concrete?

[@notwaitingtolive]

Yep 2”. I’ve done a couple basements in the same area ranging from 50-100 years old now with the same slab thickness. Once scored it breaks up easy with a good whack of a 20 lb sledgehammer.

[@PARKERBROTHERSPLUMBING]

Ok gotcha, so cut 2" then jack hammer? Would you say that's easier and faster than just jackhammering it all?

[@notwaitingtolive]

@@PARKERBROTHERSPLUMBING yes. It cuts quick and keeps the demo clean and under control. I think the fastest way (if the concrete is 2" think) is to cut and whack with a sledgehammer. The cut line give the concrete a place to break.

[@laurenharper1510]

@@notwaitingtolivewhat if the concrete is thicker than 2”?

[@christophercrager1925]

So the answer to the question is just to buy a multi hundred dollar saw? Cool.