Cutting Concrete

[Dave]

Anyone ever use a blade that goes on a circular saw for this? I'm thinking that'll give me a nice straight line, to start, and then start pounding out the rest.

Thanks

[Esox_Magnum]

Better off renting a real concrete saw, or plan on destroying your circular saw...

[JohnMickish]

Heck yes, rent a concrete saw. With the blade that you are talking about it will be very difficult to get a truly straight cut and the dust created will make it difficult to see. A rented saw will put down water to keep the dust down and have a larger blade to aid in making a straighter cut.

[Macgyver55]

How long of a cut are you talking Dave?

[Down Deep]

A carpenters saw doesn't have the power to cut concrete efficiently. It will cut the concrete mix, but good luck on any gravel or rebar that you run into. I tried it, go rent a saw.

[crothmeier]

I have an old dinosaur of a makita skillsaw that I have a slotted diamond blade on. I've use it to cut sidewalk and cement out of the basement, mainly shorter cuts. Yes, you'll beat up the saw and not want to use it for wood again, but I take only 1/2" or so at a time and make 3-4 passes going deeper each time and can get a good straight line with it, then bust the rest out with sledge. I hook my shop vac up to it to control the dust a little if need be.

If its a big job rent one.

[311Hemi]

I have used a older heavy duty worm drive skill saw to make smaller cuts in concrete and it worked just fine. The saw I have has done it many times. I had to cut a 24" x 24" hole in my basement floor to pour a new footing....but man does it make a mess. VERY VERY dusty. I don't think I would do it with a standard skill saw. If you are doing this indoors be sure to put up some plastic to try to control the dust.

Gas powered concrete saw with water is much easier and less messy.

[Dave]

I'm thinking a 12" square, to allow for the shower P-trap and then a 3" slot 3' long over to the drain pipe that's stubbed in. Gonna cut and bust up the least amount possible.

[Eric Wettschreck]

Too bad we're not closer, Dave. I have a concrete saw you could borrow.

Personally, I'd go rent one. Yeah, a skill saw with a diamond blade will get the job done, but you'll make one heckuva mess and ruin your saw. The price you'll pay for the blade may be the same as the cost of renting a saw.

[g_anoka]

Sounds like you are getting some good advice. Since I have way too much experience in doing this, let me offer a few hints. Safety glasses, hearing protection, and a dust mask. And this looks like something you are doing inside your home, so with a gas saw add carbon monoxide to the mix. This is an extremly dusty project, I would try to enclose the area in plastic to keep dust from going throughout your house. I agree with going out and renting a saw, there are now electric saws that are fitted with a vacumm that really do control the dust. Otherwise, with a hudson style sprayer, you can spray water on the blade as you are cutting to control dust.

Good luck and hope this helps.

[Macgyver55]

Four 12" cuts and two 3' cuts adds up to 10 feet of cutting. It may not seem like much, but I agree with the others, rent a saw and make your life less stressful!

I called the local Home Depot for you, they are around 100 bucks for 24 hours depending on if you want a gas or electric, and that includes a blade, or you could possibly find one cheaper up there. (maybe in Mora)

PS. I'm pretty sure I'm busy whatever weekend you are cutting and busting concrete.

But....for a hundred bucks and a case of beer you could maybe talk Eric into coming up and doing it for you!

[Eric Wettschreck]

How soon do you need this done? My folks live in Linwood and I really should go pay them a visit. Andover isn't that far away considering I'll be coming from SW MN.

Don't know when I'll be up that way, tho.

[TruthWalleyes]

Diamond blade on a concrete saw is the way to go.

BTW...When ran into your hand they leave a big scar

For cutting small blocks, you can put a diamond blade on a cutoff table saw.

[Dave]

That's why I enjoy this Garage Logic crowd, to help make a logical decision that'll keep my head from spinning. Thanks!

Eric, thanks for the offer but, the concrete's up past Mora at my cabin.

MacGyver, I have more projects for you! Let me know when your garage needs one

[trolloni]

hire a professional they have hydralic saws,they will clean up, and saw all the way through the old floor, there will be no exhaust fumes in the house that will linger!, if you run a gas saw make sure youre furnace is off or it will suck all the fumes in and reek for a long time make sure you run water on the blade or you will have dust for the rest of youre life, also a dust mask, concrete dust does not come out of youre lungs ever!make sure you know where the sewer is so you dont have to cut more than necessary .I have saws , but its cheaper for me to hire a guy in the long run, they get 5.50 a foot with 300 dollar minimun ,well worth it in my book!

[Gordie]

You can rent those saws realitively cheap dave or we have used worm gear saws to do it and even circular saws but it can take for ever with out the right blade.

Depending on what you do I have a few differenty size concrete saw blades that you could use if needed.

[Tom7227]

I think I rented one a long time ago and they measured the blade before and after and I had to pay for the reduction in diameter. Not sure if this is standard or not but it may be another cost in rental. Still would rent anyway and I agree with all the posts. If at all possible you can help the dust problem a bit if you put a window fan blowing out a window as close to the project as possible. Still use the plastic and spend more time putting up the plastic than you think is reasonable.

[Dave]

Thanks for the offer, Gordie! It's appreciated.

BUT, my brother knew a contractor that has a electric concrete saw so, looks like I'll find out tomorrow how messy cutting crete really is Quite a large blade on it so, shouldn't be any problem cutting all the way through.

[311Hemi]

Thanks for the offer, Gordie! It's appreciated.

BUT, my brother knew a contractor that has a electric concrete saw so, looks like I'll find out tomorrow how messy cutting crete really is Quite a large blade on it so, shouldn't be any problem cutting all the way through.

Put it this way, I could barely see my line after a few minutes of cutting the dust was so thick!

[Dave]

Put it this way, I could barely see my line after a few minutes of cutting the dust was so thick!

Sure, NOW you tell me And, when someone says it's a messy job, believe 'em!! Using water did keep the dust down, some, but oh what a muddy mess. I actually cut less than I figured, no 12" square on the end. BUT, I'm still not done! The end cuts do go down about 3.5 inches but, I'm having a heckuva time breaking it up. And that's with three cuts lengthwise and a few cross cuts across the width. I just must not be strong enough any more The end section should be about 12 inches thick, since they poured a 24" wide/12" thick footing for this slab. Still more to do but, we'll git-ir-done....sometime. I think I'll stop on the way next time for a jack-hammer