PLASTIC PIPES 101 Choose size according to your project
used as a vertical stack for a kitchen sink.
A 3-inch pipe is what’s used in homes to pipe toilets. The 4-inch pipe is used as the building drain under floors or in crawlspaces to transport all the wastewater from a home out to the septic tank or sewer. The 4-inch pipe may also be used in a home if it’s capturing two or more bathrooms. Plumbers and inspectors use pipe-sizing tables to tell them what size pipe needs to be used where.
The wall thickness of the pipes is different as well as the inner structure of the PVC. Many years ago, all I would use would be schedule 40 PVC pipe for house plumbing. You can now buy a schedule 40 PVC pipe that has the same dimensions as traditional PVC but is lighter weight. It’s called cellular PVC. It passes most codes and may work for you in your new room addition bathroom. Be sure to clear this first with your local plumbing inspector.
Give SDR-35 PVC a good look for the outside drain lines you want to install. It’s a strong pipe, and the sidewalls are thinner than the schedule 40 pipe. I’ve used the SDR-35 pipe for decades with fantastic success. The last house I built for my family had over 120 feet of 6-inch SDR-35 pipe that connected my house to the city sewer.
Lighter-weight plastic pipe with holes in it will work fine for that buried linear French drain. Be sure the two rows of holes aim down. Don’t make the mistake and point them up to the sky as they may get plugged with small stones as you cover the pipe with washed gravel.
This is the packing nut. Use an adjustable wrench and get a nice tight grip on the two faces of the nut. Turn it clockwise just a very small amount while facing it. You might only have to turn it of a turn or less to get the dripping to stop. Do not over tighten packing nuts.
To prevent a catastrophic flood should something go wrong while making the repair, be sure to locate your main water line shutoff valve. Understand how it works and have a wrench handy should you have to turn it off in a jiffy.