Completing a roughed-in basement bathroom requires lots of work. Placing a bath in the basement can boost the value of a finished cellar. To help you complete this job fast, we have written this how to finish a roughed in basement bathroom guide. By doing the plumbing on your own, you will be able to save around $1,000 on costing.
Steps on How to Finish a Basement Bathroom
Some people think that finishing a basement bathroom is a tough task. The truth is, it is a significant and complicated project. But it does not mean that you cannot do it. Lots of people were able to complete the job successfully on their own, and so can you.
This guide focus on installing the DWV system or the drain, waste, and vent. It is the hardest part of plumbing a basement bathroom. This task requires some hard labor, such as breaking up concrete, and enough knowledge in constructing to complete the job without any issues.
You will provide the labor and the basement bathroom ideas. The materials for drain, waste, and vent system usually cost around $250. The plumbers’ labor rates differ in each region, but the cost to finish a roughed in basement bathroom would be between $1,200 to $2,000 for a quality job.
Step #1 Look for the Main Drain Line
The first thing you need to do is to find the main drain line to connect new drain lines to the current one in the basement. Find the main stack. It is the large vertical pipe that measures around 3 or 4 inches and runs on the basement floor.
This pipe is attached to the line running under the floor and to the sewage system underneath the street. Instead of running straight, it may be angled out to the road. Check if you can find a cleanout plug in the street-facing wall of the basement. That is the spot where the line in your home is attached. And it runs directly from the main stack to the cleanout.
For those with a private septic system, the mainline will run straight on the drain field. If you are not sure where the line is, you can try other options. Create a hole where you think it could be possibly located.
You might need to widen that hole or break another exploratory one. You don’t have to worry about the cost as only the time is wasted and some money for the added bags of concrete mix you need to purchase.
Your other option is to hire a plumber. In some areas, the price may range from $75 to $150. If you are looking for a plumber with access to high-tech tools that can locate lines fast, you can find one but expect to pay $200 for his service.
Step #2 Create a Plan
Now that you have located the line, the next thing you need to do is to make sure that it is deep enough so you could create a downward slope for the new drain lines that you will use for your future bathroom.
Get a pencil and mark the entire bathroom in the basement, including the sink, walls, shower, toilet, and the drain lines. It is the best method to check out various basement bathroom plumbing layout ideas for your basement bathroom.
At this point, it is all a pre plumbed basement bathroom. You might need to do some modifications as the plan progresses. To foresee the entire project, you can create mock-up sections of the system and position them on the basement floor using some pipe and fittings.
Now that you have a clear plan on the whole system, you mark it out on the basement floor. You can use bold lines for that and spray paint for drain lines.
Step# 3 Trench the Floor
The best tool to dig up the basement floor is by using a sledgehammer. Breaking the ground can be done by whacking the floor several times. Your job gets easier once you have a starter hole since it has a space to crack and break off. Next, work on the area for the trench line.
Deal with the chunks of concrete first. Generally, the trench is big enough for your spade. As you dig around, separate the larger pieces of cement to the pile of dirt. You can use some of the soil for backfill.
Step#4 Build the Drain System
First, cut into the mainline and then splice in a Y-fitting. You can use no-hub Y-Fitting cast iron to tie the mainline. Plastic Y-fitting is also a good alternative if you need to attach short sections of pipe into the Y-fitting for the rubber couplers. You can use the same process to connect into a plastic main.
We recommend you use ABS plastic or PVC for your DWV system. These two materials are easy to cut and connect. Building branches is the most challenging part if you are working on an underground pipe. You want these branches in the right position, maintaining a constant slope of around ¼ inches per running foot.
Tips on How to Build Branches Properly
- Purchase as many fittings as you think you will need and some types that are required in your opinion. After completing this part, return the leftovers.
- Buy a torpedo level if you don’t have one. It is the handiest equipment that you can use for assessing the slope of pipes.
- Once you are done with the tube, place the dirt around so it will not move as you do the rest.
- Determine the rough-in of your basement toilet, the usual distance from the wall to the center of the drain is around 12 inches. Consider the thickness of the drywall and framing.
- Carefully backfill the trenches. Pack the soil tightly so it won’t settle later, but make sure the pipes will not move as you tamp the ground.
Step #5 Building the Vent System
As compared to building the drain system, the vent one is much simpler. You can position the vent line underneath the floor joists and do the framing in a lower ceiling. If you choose to preserve the ceiling height by putting the pipes through the beams, you will need to create some large holes, which might weaken the joists.
You can connect the new vent system into the laundry sink vent. It is best to install extra metal strapping to provide support to the pipe while cutting.
If you are not knowledgeable enough on how to finish a roughed in a basement bathroom, you should hire an expert to help you in finishing bathroom plumbing and other things. But you should prepare yourself for more expenses then.