cutting my basement floor

jeffm2

hi, new here and need some advice.
i need to replace all my cast iron sewer lines under my basement floor.
my question is, will cutting my floor basically in two or pieces wise?
is this going to cause me problems years later, with shifting and getting
uneven ?
could it be done with leaving sections together. like small bridges, if you know
what i mean.

thanks, jeffm

HooKooDooKu

As an educated guess, if there were pressures that were going to cause shifting and unevenness, I doubt "small bridges" would make a difference.

Having never done anything like this myself, if I was doing it as a DIY project, I would try to first cut a skinny trench just to open the concrete. Then, where I wanted the final openings, cut only the 1st 1" or so, and use a sledge hammer to bust open the rest of the concreate. That way, you'll have some subterainian rough edges for the new concrete to bite to tie it all back together, yet still have a strait looking cut on the surface.

plumberinlaw

what makes you think all the ci pipe has to be replaced? Have you thought about just replacing the failed section?

oh'mike

A circular saw with a diamond blade will make the cuts--they don't need to go all the way through the slab.--Concrete cutting machines are available to rent also.

Rent an electric jack hammer to break out the concrete.

Forget the 'bridge' idea--You could not get the gravel under the 'bridges' after your new drains are installed.
--Mike--

AllanJ

If the floor wanted to get uneven then leaving bridges will not keep it together.

I suggest the straightforward approach, cutting a strip above the path of the drain pipe.

I think that it is preferable to jackhammer both edges of the trench compared with jackhammering just one line and sledgehammering out to the desired trench width. The latter is more likely to result in undercutting where the concrete patch may fall down a little as opposed to sit atop or be locked into the sides of the trench.

While the trench is open, check for (rare) signs of the floor wanting to get uneven such as underground water flows (called underground springs if large) and consequent undermining of the floor slab. In extreme cases the sewer pipe can be suspended to maintain pitch using hangers embedded in the poured concrete patch covering the trench.

Been there done that.

__________________
The average homeowner who lost his house in the Oklahoma tornadoes should move for good and not rebuild. Too much complexity watchdogging the contractor. Too much a chance to be defrauded.

Creteexpert

If your basement floor hasn't cracked and shifted already it's not going to just by cutting a strip out of it. I would hire a professional concrete cutting company. The basement floor is probably around 4 inches thick. That's a lot of cutting, dust, and jack-hammering for a DIY kind of project. Not to mention the silica in the cement dust is very bad for you. A professional Sawing company will cut completely through the concrete making you a trench where you need it and the concrete can be taken out in rectangular pieces. They will use water so there is no dust and have saws that run on compressed air, so no fumes from a motor. They will have it cut very quickly and save you a lot of time and hard work.

Patching the trenches back in after can be done with redi-mix concrete from a Concrete company or bag mix like quikcrete. This depends on how much you need to do and how you want it to look after. The redi-mix will match closer to what you have there now after it dries.

http://www.everything-about-concrete.com