To those considering a career in industry, first of all, congratulations! You're looking for high earning potential, the ability to someday run your business, and enjoy the tangible results of a hard day's work. As a plumber, I want you to walk my way. To help you understand what a plumber's job is like, let me walk you through how plumbing is done.
Table of contents
- Arrive early when doing pipe laying
- Failure to plan is planning to fail
- bathroom first
- Watch out for the floor joists!
- measuring toilet
- Drains and Vents
- Glued PVC connection for rough plumbing drains
- Water lines and more boreholes
- Add recirculation line
- Handle lap joints for pipe roughing
- 3" Vent Chimney
- kitchen details
- ending
- don't be so fast my friend
- Basic engineering
- return valve
- Complete pipe roughing work
Arrive early when doing pipe laying
Usually, my apprentice and I arrive at the job site brightly in the early morning. The first thing we did was curse the cold weather, because nobody likes the cold. Hey, we're in Canada, not Central Florida like Clint DeBoer and Kenny Koehler. The first thing you do on any new job is check the power supply. If you have it, you'll be rolling out the extension cords needed to cover your area. If not, you will pull our generator and start her.
Pro Tip: If you must use a generator, make sure you have enough fuel for you to use. Breaks to run out of gas or other items not on site take time – and time is money.
However, in the last year I decided to switch all my tools to cordless so that I could leave the generator in the van to collect dust, spend less time on the job, and never have my corded tools go down when I get to the top of a ladder. Automatically unplugged because it got stuck on something while climbing up. Cordless tools are more expensive because of the batteries, but I haven't used a generator in over a year.
Failure to plan is planning to fail
The first part, and sometimes the more annoying part, is the planning phase. From here, you can draw a blueprint, walk around the house and mark where you want drainage and ventilation.
Pro tip: Visually marking each hole will help ensure you don't miss any when you go back for your last drill.
bathroom first
Next is setting up the tub. First, you'll need to actually set up and level each tub, and mark where the drain goes to the waste section. Once you've done this enough times, you'll memorize your measurements and be able to cut the holes you need without first placing the tub. The best tool for creating holes is a high torque drill such as a Hole Hawg or Stud & Joist Drill.

Watch out for the floor joists!
Pro tip: Before drilling, check to make sure you're not directly over a joist. Your boss won't be unhappy with an unpaid bill for installing new joists.
If you happen to be on the floor joists of the tub drain, all you need to do is offset the waste and spills next to the joists. But if there's a joist in the center of your shower drain, it's time to recall the framers to do their job right! But not before you check the rest of the house for framing issues.
Once the holes are cut, you can put the tub back in place, relevel it, and secure it with at least 2 inches of screws.
I'm sure every plumber has their own system, but what I like to do, once the tub/shower is in place, is to mark and drill the hole for the toilet bowl (toilet hole in the US). Believe me, if you see the joists under the toilet, you'll be uttering choice words that may or may not be for the people who built the house.
Pro tip: It's important to know what kind of toilet is being installed for plumbing. You can then check the manufacturer's shop drawings to make sure you are drilling the holes in the correct locations.
measuring toilet
If no finish is selected, I usually measure 13" from the back wall. Then, if the fixture is straight out of the tub, I would measure 15 inches. That being said, sometimes the home builder you work with will specify specific measurements. Then you have to verify and copy it. Usually, a 4-1/2-inch hole saw will do the trick when drilling a hole for a toilet drain.
Drains and Vents

Now is the time to drill out the drainage and ventilation holes. If you're not already using a Hole Hawg style drill, you'll really want one at this stage. Usually what I do upstairs is open up all the vents to the ceiling. After doing all of this, I got up and went into the attic to hook up the appropriate vents and then hook them up to outside air by using a roof booster.
One very important thing in the plumbing industry is the following words: Drainage must be graded. The slope must be set at ¼ inch per foot for pipe up to 3 inches and 1/8 inch per foot for 4 inch pipe.
Pro tip: Be thoughtful and aware when other tradesmen are setting up around your work. For example, in a ceiling, the HVAC needs to tink up through the same area, so stay high or low in the joist space. Giving them space is not only considerate, but it makes you look like a professional.
Glued PVC connection for rough plumbing drains
When it comes to gluing drainpipe pieces together in new construction, there isn't much like glue. With your application brush, apply a generous amount of glue to the hub of the pipe and fitting, then when it's time to put on your fitting and grade it, push and turn left then right before setting your grade. The reason we do this is to make sure there are no bare spots inside the glued seams. Then, once the fitting is in place, wipe off any excess glue.
Water lines and more boreholes
Now that we've finished draining and venting the basement, what's the next step? If you have an apprentice, you might have him or her focus on plumbing the upstairs fixtures. In new construction the only type of PEX (cross-linked polyethylene) my company uses is PEX A (specifically Uponor) and the connections are made with expanded PEX.
Be sure to check out our article on what is PEX pipe to learn more about the three types of PEX pipe.
In my opinion, the best way to run water lines for residential plumbing is to run 3/4 inch pipes close to where you have bathroom groups or other fixtures that require them. This includes refrigerator lines, washing machines, or kitchen sinks.
Then, erect a header and reduce the 3/4" waterline to 1/2" for each individual fixture. Target? Keep these 1/2" wires as short and straight as possible for your plumbing. This reduces wasted water. Never accidentally kink any waterline. However, with PEX A, you can simply use a heat gun or flashlight to remove kinks.
Add recirculation line
You can run the recirculation line to the main farthest from the hot water tank. This connects to a pump mounted on the hot water tank. It circulates hot water throughout the house. This allows you to enjoy near instant hot water when you turn on the tap. Under Canada's new heating codes, the entire hot wire needs to be insulated throughout the home. Because of this, recirculation lines have waned in popularity in new build homes.
While your apprentices are working on plumbing thick lines (or after you've finished them), go outside and drill holes in the hose spigots. You'll also need to drill holes for the sump pump, hot water tank, and anything else that needs external ventilation (as shown in the blueprints). In northern Canada we have to use frost free hose spigots and mount them with an upward slope. This ensures that the lines do not freeze in winter.
If you have an apprentice running the plumbing, now is the time to check them out.
Handle lap joints for pipe roughing
Once you're in the basement, it's time to start matching. This typically includes several key tasks:
- tie any half bath together
- Drain the emergency floor drain in the upstairs laundry room into the mechanical room and plug it to make sure it doesn't get covered
- Preparing vents for rough double ducting (a fancy word for basement bathroom vents)
- Depending on how your upstairs drain system works, the chances of dropping your main 3" chimney as well as another chimney
3" Vent Chimney
Regarding those 3" vent chimneys – the easiest and neatest way to put these down is to tie them together where local codes allow. To do this, run to the structural beams. Next, drop to the top of it and run the tie at the lowest slope level. Strap down anything you come across along the way, like another pile or the kitchen sink. When using this method, use a Y-joint with a 45° or a joint 45° elbow for horizontal connections.
Pro Tip: For my plumbing installations, I also usually put a 3" joint cleanout at the farthest Y-joint on the horizontal branch. It's not required for the code, but it's good plumbing practice. It helps if something is clogging the horizontal ductwork. Instead of feeding a drain cleaning tool from one of the above floors, all you have to do is carefully unscrew the cleaning unit and let your snake run a few feet.

kitchen details
The type of fit you use for your kitchen sink depends on the location of the sink. Is the sink on an island where you can fully walk around? If so, then you can simply angle the drain up 45° and run it about 8 inches through the floor. You don't have to do anything else here, as you'll be using an air admittance valve (aka cheat vent).
If the sink is installed on an island that is attached to the wall, an island vent must be used. Yes, I know how much we love these puppy pipes, but they are a necessary evil!
Finally, if installing the gutter on an exterior wall (where the pipes might freeze), install a flat vent in the gutter. But what are flat vents?
Flat vents are horizontal sections of drying vents that connect to soil or waste pipes. The basically flat vents are located mainly on the exterior walls, fearing that the drains would freeze. The vent goes into the cabinet, connects to the drain, and goes down through the floor.
ending
During plumbing, collocation also involves running water lines in the basement. Do this and you'll be almost homeless! Just run your 3/4″ PEX into the mechanical room, adding joints along the way. This takes care of any main floor or basement fixtures you roughed in. Finally, terminate the hot and cold water lines around where the hot water tank is.
don't be so fast my friend
Once you're rough in the house and down into the basement, look around and admire your work. Make sure you have bound everything correctly according to the code. Head upstairs with your apprentice and start plugging and connecting pipes in place. Use protective boards wherever drainage runs over studs or the bottom of walls. These protective plates ensure that drywall workers cannot accidentally drive screws into your gutter system.
Basic engineering
After finishing the interior of the house, start the foundation work. It's tempting to ask your apprentices to solve the problem of digging sewers. You'll want to help him if you want to get home in time for kickoff. Once you get to the bottom of the main building sewer, see how much room you need for the slope. Compare this to how deep your sewer goes into your house.
This is a simple math problem. Use a tape measure to measure the distance from the bottom of the drain to the furthest chimney. Next, figure out how big of a drain you'll be running. This helps determine which grade you need to use. Using these two numbers, you can calculate the rise of the pipe using the following formula:
Ascent (or descent) = run x rank
Once you figure out how much space your gutter needs, you can decide if you need to roll the drain.
return valve
The next step for Alberta is to install a device called a normally open backwater valve. Its role is to protect the house if the sewer becomes clogged for any reason. If this happens, a flap is opened, sealing the house away from any potential hazards.
Backwater valves generally come in two types: normally open and normally closed. You can use a normally closed backwater valve on a branch drain that needs protection for the fixture it serves. An example includes a basement laundry room that needs to be tied down before the main backwater valve can be installed. The reason we typically use open backwater valves is because houses are used to drain the city plumbing system. They need a constant flow of fresh air to keep everything running.
Complete pipe roughing work
Once the groundwork is complete, the final step is to run the water service to where the print requires and shut off the water supply. You can then water test the house to make sure there are no leaks before the drywall starts to rise.
Rough machining in the plumbing industry is a labor-intensive job that is physically taxing, but at the same time very rewarding. Now that you know how to do plumbing roughing, maybe you can help if that's the route you've chosen in your career as a tradesman.
Of course, we understand that you may be doing things differently in your territory. If so, be sure to leave a comment below to let us know how you work in the workplace.