How to Run a Water Line to a Detached Garage?

Garage Storage Lab is reader-supported. When you buy through links on our site, we may earn an affiliate commission.

When you have a detached garage, you can use it for parking, guest room, and additional storage. However, if you don’t have a water line in your detached garage, you’re depriving yourself of other garage benefits.

For example, when you have a water line in your detached garage, you can use the space for a washing machine or even a shower area for your guests. 

If you’re wondering how to run a water line to a detached garage, you’re in the right place. 

How to Run a Water Line to a Detached Garage

How to Run a Water Line to a Detached Garage?

The process of running a water line from the house to the shed or a detached garage can be cost-effective or expensive, depending on how you run the plumbing project.

4 Factors that Affect the Cost to Run Water Line to Garage

Before starting the project, you need to consider the following factors to calculate the garage plumbing cost:

1. Cost of the Materials

The first thing you’ll have to consider while calculating the garage plumbing cost is the material cost. Material costs include the price of valves and pipes.

There are several options for garage pipes. For example, you can PVC pipe, PEX pipe, ABS pipe, etc. While selecting the pipe, you should consult with a professional technician.

Again, if the depth of the main sewer line is deeper than the average depth, you’ll need more pipes and additional materials, which will eventually increase the cost of garage plumbing.

2.  Garage Ventilation

Before installing a water line in your detached garage, you’ll have to ensure that your garage is ventilated properly.

Because when your garage isn’t ventilated, you’ll have condensation and moisture issues, which will make your stay in the garage uncomfortable. That’s why if you haven’t added ventilation in your detached garage, you’ll have to consider the garage ventilation cost.

While adding ventilation in your garage, you’ll have to install a plumbing vent on your garage roof.

3.  Garage Insulation

If you want a hot water supply in your detached garage, you’ll have to insulate your garage. When you have an insulated detached garage, you can install water heaters inside of your garage. You won’t require a hot water supply from outside.

For higher efficiency and cost savings, you can install a tankless water heater inside your detached garage.

4. Garage Foundation

Usually, most garage foundations are made of concrete. But when you have a concrete garage foundation, the plumber will drill the concrete floor, requiring more time and increasing the cost.

How to Run Water Lines to a Garage: Step by Step

While attaching water lines to your detached garage, you’ll have to remember that each garage plumbing project is different, and the cost will vary from one to another.

If you want to do garage plumbing at a minimum cost, consult with an experienced plumber and implement the tips he provides. Besides, before starting the garage plumbing project, check the plumbing regulations and building code guidelines to avoid unwanted situations.

Step 1: Plan the Plumbing Connection

Before starting the project, you’ll require a solid design plan to make your garage plumbing successful. To design a plan for garage plumbing, you should hire a plumbing team or plumber.

A plumber will help you decide where to install the sink, shower, bathroom, etc. If you want to reduce the overall cost, you need correct placement, and only a professional plumber can help you do that.

Apart from this, a plumber will help you in connecting the drains and pipes.

After finalizing the garage plumbing design, you’ll have to find out the existing closest plumbing to your detached garage. Then you’ll require drainage pipes to make your slope function properly.

If you’re doing this garage plumbing with the help of a plumber, you can ask the plumber to do all these for you.

Step 2: Dig Out

After deciding how to connect the existing plumbing to the detached garage, it’s time for digging out. Unless you know every aspect of plumbing and drain lines, you should hire a plumber or plumbing team.

If you have a concrete garage floor, plumbers will require more time than usual. Again, while digging, plumbers may have to dig holes both outside and inside of the house.   

Step 3: Install the Plumbing

When digging is done, it’s time to install all the plumbing, fixtures, and ventilation. If you’re doing the garage plumbing yourself, you can easily install the bathroom, toilet, and sinks. However, for pipe and drain line installation, you’ll require help from a professional plumber.

Step 4: Inspection

When you’re done with all the plumbing work, your detached garage needs to be inspected by the city authority. If the city inspection suggests any change, you should do it as soon as possible.

FAQs about Running a Water Line to the Detached Garage

1.     Which pipe should I use for garage plumbing?

You can use copper, PVC, or CPVC pipes for your garage plumbing. If budget isn’t the issue, you should use copper pipes. Otherwise, you should use PVC pipes in your garage. However, before using PVC pipes in the garage, make sure it’s authorized in your area.

2.     What should be the diameter of the plumbing pipes?

It entirely depends on your required flow. If your house is fed by smaller pipes, there is no advantage to using pipes with a larger diameter.

3.     Do I need city permission to run a water line to my garage?

Yes, you must need a city before doing any plumbing work in your work. Besides, when the plumbing is done, it needs to be inspected by the authority.

4.     Does garage flooring affect the overall plumbing cost?

Yes. If your garage is made of concrete, it’ll require more time for digging, which increases the overall cost of plumbing.


Attaching water lines to the detached garage sometimes can be challenging. That’s why it’s better to hire a plumbing team or plumber for this home project. 

Helpful Products For Your Garage

Thank you for reading this article. I hope you found it helpful. Here are a couple of websites I’ve found that have some helpful products I have personally used to organize, maintain, and help add some style to my garage over the years.

These are affiliate links, so if you do decide to use any of them, I’ll earn a commission. But in all honesty, these are the exact products that I use and recommend to everyone, even my own family. – does have everything you need to create the most attractive and organized garage on your block. I purchased Garage Basics Diamond garage floor tiles for my new garage floor and I couldn’t be happier with the result.

Click the Garage Basics website link above to find everything from storage racks to garage workbenches and see why this is my go-to site when looking for products to improve my garage. – sells a large selection of replacement garage door opener remotes, keypads, and receivers all in one place! When my LiftMaster remote failed last year, came to my rescue.

I was really surprised at the number of brands they carried and their prices were lower than I could find anywhere else. If you need replacement parts for your garage door remote, keypad, or receiver, click the link above. Plus, shipping is free on orders in the United States!

If you need replacement parts for your garage door remote, keypad, or receiver; click the link above to see why they’re the best.

Hi, I am Brent Hartman. I am a DIY enthusiast and love to improve and organize the garage in the most innovative way. I created this website out of my passion for helping people organize their garages.

As an Amazon Associate I earn from qualifying purchases.