LAUNDRY ROOM PLUMBING ADDITIONS IN SEATTLE

Laundry room plumbing, washer relocations & additions done to code

Same-day appointments · ★★★★★ 5-Star Google Reviews
Licensed • Bonded • Insured • Residential & Commercial

Call us now for any and all plumbing needs!

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ADDING OR MOVING A LAUNDRY ROOM?

We handle the plumbing for new laundry rooms, washer relocations and laundry sinks, done to code and ready for inspection.

Washer box & supply lines installed or relocated
Drain & vent rough-in for new laundry spaces
Laundry sinks and utility tubs
Gas lines for dryers
Permits handled, with clear, upfront pricing

Prefer to talk? Call or text (206) 858-2211

EXPERT PLUMBING FOR LAUNDRY ROOM REMODELS & ADDITIONS

Adding a new laundry area or upgrading your existing setup? Knockout Plumbing & Mechanical offers expert plumbing support for laundry room additions across the Seattle area. Whether you’re converting a basement, adding a second-floor washer, or designing a full utility space, we make sure your plumbing is done right the first time.

Our licensed plumbers handle everything from new water and drain lines to venting and valve installation. We ensure all work is code-compliant, leak-free, and ready for inspection—saving you time, stress, and rework.

We collaborate with homeowners and contractors to keep your project on schedule, and we offer guidance on fixture placement, water-saving appliances, and smart shut-off valves.

Our Laundry Room Plumbing Services Include:

✅ Hot & Cold Water Supply Lines
✅ Drain Line Installation & Venting
✅ Washing Machine Hookups
✅ Utility Sink Installation
✅ Pressure Regulating Valve Setup
✅ Code-Compliant Plumbing Fixtures
✅ Flood Prevention Solutions

FAQ – Laundry Room Plumbing

How long does laundry room plumbing take to install?
Most laundry room additions take 1–2 days depending on how far the space is from existing water and drain lines, and whether any rerouting is needed.

Can you install a washer and dryer in a new location?
Yes! We specialize in relocating laundry hookups, and can add the necessary water supply, drain lines, and proper venting for new washer/dryer setups.

Do I need a permit to add a laundry room?
In most cases, yes—especially if plumbing or electrical is being added or moved. Knockout Plumbing handles all necessary permits and ensures everything is code-compliant and inspection-ready.

What kind of drain is needed for a washer?
A standpipe drain connected to your home’s main drainage system is most common. We’ll make sure it’s properly sized and vented to avoid backups.

Can you install a utility sink along with the washer and dryer?
Absolutely. We often install utility sinks as part of laundry room upgrades, which can be handy for rinsing or pre-soaking items.

👉 Planning a laundry room remodel? Contact Knockout Plumbing today for a custom estimate or help with your permit process!

    
 
 
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    Justin Gerardy 
 
 
 
 Trustindex verifies that the original source of the review is Google. As a restaurant owner in Seattle, I tend to find it infuriating when tradespeople over charge. It’s a real problem in this city. Knockout was fair and fast. Can’t say how much I appreciate it. I’ll be back for sure.
  
 
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    Margot Potts 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zack and his crew were able to come within a couple days of calling and resolved my issue within minutes. They were very friendly and generous - highly recommend!
  
 
      Posted on Google  
    Veronica Seifner 
 
 
 
 Trustindex verifies that the original source of the review is Google. Knockout was great to work with - very courteous, responsive, and fair pricing. Zach came out to cap off a gas line for an appliance we switched to electric. The option was to do it from the inside or from the outside and remove the dedicated pipe altogether. Zach gave reasonable pricing (checked with two other companies) and was able to get the job done right away with expertise and professionalism. Knockout will be our top-choice, first-call for any future pluming needs in our home.
  
 
      Posted on Google  
    Mindy Martin 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent experience. I was considering replacing my water heater back in the spring and Knockout was one of the companies I shortlisted to talk to. Ultimately I decided to wait on replacement, but Knockout was definitely at the top of my list. When my water heater started leaking the other day, I immediately reached out to Knockout, and they were able to get me scheduled the next day! I was given the choice between Bradford White and AOS. Zach came out and did a fantastic job. Friendly but professional; quick and efficient but thorough. Knockout respected the quote I was given a few months back which was very competitive. I strongly recommend this company!
  
 
      Posted on Google  
    rozap _ 
 
 
 
 Trustindex verifies that the original source of the review is Google. I asked these guys about hydrojetting our old sewer line that would occasionally get clogged. Zach showed up and looked at the situation, and after chatting for a bit he figured I could DIY it so I would know how to do it rather than paying every time it happeened. So he showed me a fitting for my pressure washer I could get, and described what to do. I did all that and it worked great, and I saved $850 that it would have cost, and then I knew how to do it going forward. They didn't even charge me. They're super honest guys with a lot of integrity. Definitely recommend them.
  
 
      Posted on Google  
    Jason Franklin 
 
 
 
 Trustindex verifies that the original source of the review is Google. Colin and his team have completed 2 projects for us and is always very helpful and informative in his diagnosis and explaining his course of action. I highly recommend him and Knock out Plumbing for all your plumbing needs.
  
 
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    Michael Johnson 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zach has done a number of plumbing jobs for us over the years ranging from large bathroom additions to smaller repairs, every time they've been top quality. I highly recommend Knockout!
  
 
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    Simone 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zach is a consummate professional. He was thorough, timely, efficient, personable, and diligent. He returned the next day after the job to place a cover on a part, which is something my partner & I wouldn’t have known. Clearly, he has integrity, which in my book is paramount. We emphatically would not recommend anyone else, but him and his team for plumbing jobs. We were beyond pleased with Zach’s skill and caliber. 20/10 ⭐️
  
 
      Posted on Google  
    Evan Wiederspan 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zack and his crew replaced my kitchen sink drain after it started leaking. I was really happy with the price, and the speed and quality of their work. It was also easy to get a quote and schedule over the phone. I would definitely hire Knockout Plumbing again in the future!