Cutting concrete

[Marc Britten]

For a medium sized job is it worth purchasing a moderately priced diamond concrete blade vs an abrasive blade for cutting old concrete slab up?

There are a number of concrete blocks on my property, a few fairly long that I need to break up.

I removed one of the smaller ones with an abrasive blade on my circular saw. Scored it and then split it with a hammer/chisel. However that wasn't very large and ate up the entire blade to slit it in enough places to make the chunks manageable.

I guess I'm wondering how the life of a diamond blade is, and is segmented better than continuous for old concrete.

[Bob M.]

If this is a one-time deal, why buy? Check out the local rental shop. They'll have the industrial strength stuff you need.

[BobK207]

Marc-

Need more info.......how many inches (feet?) of cuts will you need to make?

How thick are these blocks?

If it's just demolition why even bother with scoring.....just use a repeated series of moderately heavy blows along the desired line of fracture. Unreinforced concrete doens't stand up well to repeated hammer blows & can be encouraged to crack.

I've broken more than my share of concrete slabs (patios, sidewalks) without cutting.

If you insist on scoring & the amount doesn't justify renting, get a Hilti, Bosch or DeWalt blade for your circular saw but be warned that the mess & dust isn't too good for you or the saw.

I bought a 6" diamond blade YEARS ago when they were quite expensive, I've bought others (4" & 4.5") since then. I've scored or cut

100's of feet with the 6" over the years.

The segmented ones clear the cut better but do not cut as chipfree as continuous rim but for demo segmented is fine......

.btw wet is better than dry.................. less heat & dust but still pretty messy.

cheers Bob

[Jim Elbrecht]

-snip-

-snip-

Second that. The 6" will outlast your circular saw unless you hit some rebar.

OTOH- check to see what it would cost to rent a gas powered 12-14" wet saw for a day.

Or if straight edges aren't important, use a 20 lb sledge & sweat. Get a bar under a corner of the slab & raise it a bit- slide a 2x4 under - and break away the overhanging pieces. Easier than you think- especially if you have a helper- but I've done 6" thick 10' x

10' pieces of air-entrained concrete in a day- and I'm an old fart with a bad back & weak heart.

Jim

[HeyBub]

Break the concrete, don't saw. Cutting will take DAYS.

[EXT]

I have found it best to dig a hole under the slab and put a scissor type or hydraulic car jack under it and lift an edge up, wedge something under it and pound away. Even with re-bars concrete will break-up when it is unsupported from underneath.

[hallerb]

rent or buy a electric jackhammer, pretty cheap at harbr freight

[barry]

What are you calling a "concrete block"? How long is "fairly long"?

Diamond blade for demolition? Hardly, if rental jackhammer available.

J

[Phisherman]

If both are used properly your circular saw will likely end its life before the diamond blade. Sawing concrete produces a lot of fine dust and grit--not good for your saw and lungs. A jack hammer is the best way to go.

[Homer]

I rented an electric jackhammer for about $30 and took out my patio slab and kitchen slab. Had it back at the rental place in 4 hours.

[Marc Britten]

Probably 50-60 feet (2 10' runs, and 3 feet runs every couple feet along that)

3 to 4 inches. I didn't measure the one that I broke up but fairly thick without being basement slag/garage thick.

This is probably a case of, cause that's what I got in my head.

The suggestions of lift and wack seems to be pretty good and I'll see what I can work up in that area.

A chunk of my deck sits on part of one of the pieces I want to break up, so I'll probably need to score that area, but I still have a abrasive disk or 2 left over.

Thanks for the input.