For most residential work that’s within 24″ of slab level, 12-16″ is plenty, assuming that it’s placed accurately. You can always bell out the trench under the slab a bit if needed for a large assembly.

How deep are plumbing pipes under a slab house Australia?

about 600mm deep





Why it’s so hard to repair sewer pipes under slabs. Houses that are built on slabs have a concrete beam around the edge that is usually about 600mm deep.

How do you lay pipes on a concrete floor?

Quote from the video:
Quote from Youtube video: We've got some rebar with a wire harness just sitting across to keep it in place the toilet flange you want to have just above the grade of the concrete. Again you'll be able to cut that out flush.

How do you cut a trench in a concrete slab?

Cut the concrete as based on your guide cut, rotate the depth handle to lessen the blade sharpness if needed. Slowly push the saw forward until the first edge of the trench is cut. Raise the blade then pull the saw back to the end of the trench and cut the second edge similar to what you did with the first edge.

How do you rough water supply lines?

Steps for Roughing in your Plumbing:

  1. Step 1)Mark Key Locations. Determine where all the toilets will be and mark its center on the wall and measure out 13 1/2 inches from that point. …
  2. Step 2) Cut the Drain Hole. …
  3. Step 3) Drain Pipe Installation. …
  4. Step 4) Supply Line Installation.





How do I run a PVC pipe under a concrete slab?

Quote from the video:
Quote from Youtube video: The concrete patio. And smooth out as best as possible. Then go ahead and place your makeshift sphere. Into your little trench area and start getting ready to count away.

How is plumbing run in a slab home?

Quote from the video:
Quote from Youtube video: And so they put the basic plumbing some of the water runs of course go through the walls as well but they get their basic plumbing runs in the ground before the slab is poured.

How do you install plumbing in a slab foundation?

Quote from the video:
Quote from Youtube video: It's going to go down that blue pipe is ultimately where the plumbing. Drain is going. So if you look here. It's three inch pipe that's a standard inside of the house nowadays pvc.

How do you layout under slab plumbing?



Quote from the video:
Quote from Youtube video: I just set up and I level down with a level to make sure I'm with my string.

How do you run a water line under a slab?

Cut a hole through the soil under the slab foundation using a high-pressure washer. Place the hose end to the soil under the slab foundation and turn the washer on. The high-pressure water will cut a hole through the soil through which you can lead the new line under the foundation.

What is considered rough-in plumbing?

A plumbing rough-in means that all water supply and drain pipes have been run through bored holes in the studs and other framing members and that all pipe connections have been made. No sinks, faucets, or other fixtures and end elements have yet been installed at this phase.

How do you build a plumbing layout?



To make a plumbing plan, first draw all fixtures to scale size and make sure they are not too close together. Mark the drain lines and vents for the fixtures, then add the supply lines. Make riser drawings to show vertical pipe runs as well.

How high off the floor should a water supply line be?

Supply line (height): Ideally, the toilet’s water supply line enters the room at 8 1/4 inches above the floor. More broadly, this cold-water-only pipe creates one hole between 5 and 10 inches above the floor.

Can a shower and toilet share the same drain?

The general answer is that the showers and toilets can use the same drain, but they should not be sharing the same waste trap arm. There are other factors to consider as well, such as whether your drains lead to the main sewer line, or if there are septic tanks that are used in your city or town.

How do you rough plumb a new house?

Quote from the video:
Quote from Youtube video: That will help you with getting everything hooked up without having two ends where you can't get a piece of pipe in there so i build off my main trunk and i work back to the bathrooms.

When installing a drain line how many inches should the drain line be installed off the floor?



Supply lines are usually placed high enough from the floor to accommodate a standard sink faucet or toilet. For example, this means that most water supply lines will be installed around sixteen to twenty-one inches from the ground for a sink faucet.

How much slope do I need for a 3 inch sewer pipe?

704.1 Slope of Horizontal Drainage Piping

SIZE (inches) MINIMUM SLOPE (inch per foot)
21/2 or less 1/4a
3 to 6 1/8a
8 or larger 1/16a


Can a toilet and sink share the same drain?

Run the lower sink drainpipe, adding elbows or collar connections as needed to reach the 3-inch drainpipe that runs from the toilet. The configuration depends upon your bathroom layout and the direction of the floor joists, but connect the sink drain to the toilet drain within 6 feet of the toilet, if possible.

What is the fall of a 4 inch sewer pipe?



For 4-inch PVC piping and a building sewer less than 50 feet long, the minimum slope is 1 inch in 8 feet, or 1/8-inch per foot, and the maximum is 1/4-inch per foot. For sewers longer than 50 feet, the slope should be 1/4-inch per foot.

Can you put a 90 in a sewer line?

It’s fine to have a larger-radius (sweep) 90-degree bend at the base of a vertical drainage stack where the wastewater starts to travel horizontally. It’s also a good idea to have a sweep 90-degree fitting where a drain pipe pops out of a wall for a kitchen, vanity or laundry sink.

Can a sewer line be too steep?

A slope that is too steep will cause the liquids to run faster than the solids, leading to clogs. A slope that is too shallow does not create enough velocity for proper drainage.