DIY Plumbing Vent
This is a toilet drain pipe. The smaller pipe that connects on the right side is a vent pipe. It looks like it’s installed correctly until you look what happens on the other side of the wood beam! Copyright 2025 Tim Carter
DIY Plumbing Vent and Other Mistakes - Use My Phone Coaching Service
I did an in-person inspection consultation several days ago. A man purchased a 50-year-old home next to a ski resort. He and his family are avid snow skiers and were tired of renting expensive condominiums. He wanted my opinion about the condition of the house, and how to schedule remodeling work that might span two or three years.
CLICK HERE to set up a DIY Plumbing Vent phone coaching call.
Part of my coaching service is to mark up photos you send me. I will show you exactly how to install the pipes. LOOK AT THIS ONE:
I’m not sure of how much money he has, and it’s none of my business. That said, I know he’s going to need at least $500,000, or more, to remodel both the inside and outside of the home based on the plans he showed me. This tired home requires a full facelift both inside and outside.
Radiant Heating System on One Zone!
I discovered the radiant heating system and most of the plumbing drains and vents are installed incorrectly. It turns out the previous owner was an avid DIYr. He knew just enough about building and remodeling to be very dangerous.
The first thing I noticed upon entering the house was the 3-inch toilet drain pipe visible between two ceiling joists above my head. This pipe had an oversized 2-inch vent pipe. A 1 1/2-inch vent would have been sufficient and code-compliant.
The DIYr had to flat-vent the drain pipe because it was in a narrow joist space. He did the right thing by rotating his fitting. This prevents toilet water from back flowing into the vent pipe. Unfortunately, he used a tee fitting instead of a wye. A tee fitting allows two pipes to connect at a 90-degree angle. A wye fitting makes the connection at a 45-degree angle. Wyes mimic Mother Nature. Many streams tend to merge into rivers much like you merge into high-speed traffic on highways.
Using the tee fitting wasn’t his most grievous error. He extended his vent pipe about 30 inches and then went down four inches. He was extending the pipe to a place where he could turn it up into a wall. This horizontal length of pipe is no different than the p-trap under your fixtures. My guess is after all these years, that horizontal pipe had filled with water rendering the vent useless.
Vent pipes need to be sloped at all times like drain pipes. This allows the condensation inside the pipes to drain by gravity to the sewer or septic tank.
This DIYr also made a serious mistake on all his soldered copper water lines. I could see the green remnants of the liquid flux that had flowed down over the tubing as he soldered. He didn’t clean the flux off the pipe. This excess flux can lead to corrosion in the future. Old towels cut up into rags do a great job of removing this soft flux once the copper pipe is cool enough to touch.
Water Lines Must Be Big
You might make a serious mistake sizing water lines. I’m discovering more and more that folks who install a luxury shower are disappointed when water dribbles from the body sprays and shower head. Luxury showers can gulp 10 or 11 gallons of water per minute when you transform your shower area into a car wash. One-half-inch-diameter water lines will not suffice. In some cases, 3/4-inch-diameter water lines may not work. Keep in mind that PEX water lines often have a smaller inner diameter than copper!
There's water flowing from the large shower head. However, as soon as you turn on the three body sprays water dribbles out of every orifice in this luxury shower. The East Coast plumber was a dunce. Copyright 2025 Tim Carter
The current craze of luxury vinyl plank (LVP) flooring may cause a water leak in your home. It happened to a friend of mine. You, or the flooring installer, may remove a toilet in a bathroom allowing the LVP to be placed under the commode. If the toilet was installed with a time-tested wax ring, you automatically break the seal when you lift it up.
A secondary problem can occur because the top of the toilet flange is now flush or below the new finished surface of the LVP. Toilets are designed such that the toilet flange should sit on top of the finished flooring. You may have to stack two wax rings on top of one another to get a water and gas-tight seal.
Teflon tape can cause you to pull out your hair. I’ve never been a big fan of it. I prefer to use gloppy thread-sealant compound brushed onto the male threads of a pipe. DIYrs often don’t wrap the teflon tape onto the threads tight enough, or they wrap it on the wrong direction. Teflon tape needs to be wrapped in a clockwise fashion as you look at the end of the threaded end of a pipe.
Are you thinking about installing a new garden hose faucet? Most plumbers and almost all DIYrs pipe hose faucets with a 1/2-inch-diameter supply line. You’ll be astonished how much more water you get out of a garden hose by feeding the hose bib with a 3/4-inch pipe.
If this new hose faucet is going to be inside a garage, consider installing a hot/cold hose bib like I have at my own home. These hose faucets work just like your kitchen sink. You can have all hot water, all cold, or mix them for warm water. Washing dogs, cars, or any other item in chilly weather is so much nicer when you have hot or warm water.
Column 1614