Need some expert advice on concrete cutting

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Easy Livin’ 3000

Minister of Fire
Dec 23, 2015
3,018
SEPA
My 1700's vintage house has had many additions. One of the additions was built over an earlier edition concrete slab porch. And, that addition is now the kitchen. Right over the earlier concrete slab. They plumbed around the concrete stab, then they put down the floor, and then the kitchen cabinets.

Now, the plumbing to the kitchen sink has many leaks in the copper pipe, and the old gate valves are completely rotted out.

The only way that I can get the plumbing fixed, is to cut a channel through the concrete slab, and re-route the pipes through that channel. If I can't do that, I"m going to have to take up the cabinets and the floor. UGH.

I have a diamond blade for my circular saw, and I plan to cut some kerfs into the concrete slab to the full depth of the 7 inch circular saw blade. Then chip out the waste. Run the PEX down the new channel, and top it off with something before putting down the finished floor.

What do in need to worry about when cutting the kerfs in the old concrete slab?. They will be 6 feet long (the old porch was 6'.
 
You might want to rent a special saw. Cutting concrete dry will create a huge amount of nasty dust that you don't want to breathe or get in the house. IMO, you should get a saw that will cut the concrete wet, so as to eliminate the dust. The moron I used to cut the concrete in my basement ignored my orders to cut it wet, and cut it dry - while I was at work. They used a vacuum to try to capture the dust, which didn't work at all. The entire house was filled with dust so thick you could barely see across a room. All the doors in the house were closed, but that dust got everywhere. Even inside kitchen cabinets. I was a tad upset...
 
People add pipes in slabs all the time. You can either sawcut it and hammer out the trench or you can just hammer out the trench which is surprisingly easy to do straight. I would suggest that the trench run all the way through the slab so that you can place your pipes below the slab in soil/sand.

You can rent a walk behind sawcutter (Wet) but you'll need to deal with all the water. Jackhammer didn't make much dust but the edges are more ragged.