New construction plumbing in Knoxville, TN.
Building a custom home, adding on, or gutting a house down to studs? Hard Knox Plumbing handles residential rough-in through trim-out — permitted, inspected, and scheduled around your build so the trades behind us aren’t waiting.
Licensed and insured. Plans reviewed before the slab goes down. Clear pricing, real schedules, and a workmanship warranty on the finished system.
Get it right in the walls
The plumbing decisions you can’t undo later.
Once concrete cures and drywall goes up, plumbing changes get expensive fast. Drain slope, vent routing, fixture locations, water heater placement, and line sizing are all cheap to optimize while the project is still on paper — and painful to revisit afterward.
That’s why we like being in the conversation early. We’ll review the plans, flag the spots that will cause trouble, and lay out a system that will still be quiet, efficient, and serviceable in twenty years. Then we install it to code and stand behind it.
For builders, the value is simpler: we show up on schedule, we pass inspection, and we don’t hold up the trades behind us. For homeowners running their own build, we translate — plainly — what each choice means for cost, performance, and daily life in the finished house.
Planning a tankless water heater? Gas line sizing and venting are far easier to get right during rough-in than as a retrofit. Tell us early and we’ll build for it.
What We Handle
Rough-in through final inspection.
Underground & DWV rough-in
Under-slab drain lines, waste and vent piping, and stack routing laid out for correct slope and long-term serviceability.
Water supply piping
PEX or copper supply lines sized for real simultaneous demand, with accessible shutoffs where a future owner will thank you.
Gas piping
Ranges, fireplaces, tankless heaters, grills, and generators — properly sized, pressure tested, and permitted.
Water heater systems
Tank or tankless, with the venting, condensate, and expansion provisions built in from the start rather than added on.
Fixture trim-out
Faucets, toilets, tubs, showers, sinks, disposals, and hose bibs installed, tested, and walked through at the end.
Permits & inspections
Permits pulled and inspections coordinated with City of Knoxville, Knox County, and surrounding jurisdictions.
How We Work
A build schedule you can plan around.
Plan review & bid
We read the plans, ask the questions that matter, and return a clear scope and price — not a number that changes at rough-in.
Underground & rough-in
Drains, vents, supply, and gas installed and tested, timed to keep framing, HVAC, and electrical moving.
Inspection & close-in
We meet the inspector, pass, and release the walls so drywall isn’t sitting on our schedule.
Trim-out & handoff
Fixtures set, water heater commissioned, everything tested, final inspection passed, and warranty documentation handed over.
Common Questions
New construction questions, answered.
Do you work with builders and general contractors?
Yes. We handle residential new construction plumbing for custom builders, general contractors, and homeowners acting as their own GC. We coordinate around your framing, HVAC, electrical, and inspection schedule — and we show up on the day we said we would, which is most of what a builder actually needs.
What does a plumbing rough-in include?
Rough-in is everything inside the walls and under the slab before drywall: DWV (drain, waste, vent) piping, water supply lines to every fixture location, water heater and laundry connections, gas lines if applicable, and the pressure and inspection testing required before the walls close.
When should I bring a plumber into the project?
At the plan stage, before slab or framing. Fixture locations, drain routing, vent stacks, and water heater placement are inexpensive to optimize on paper and expensive to change once concrete cures or joists are set. Early involvement is the cheapest money in the whole job.
Do you handle permits and inspections?
Yes. We pull the required plumbing permits and coordinate rough-in and final inspections with the local authority, whether the project sits in the City of Knoxville, Knox County, or a surrounding jurisdiction like Farragut, Loudon County, or Blount County.
Can you plumb additions and major remodels too?
Absolutely — additions, garage conversions, basement finishes, primary suite additions, and whole-house renovations. The work is the same discipline as new construction, with the added care of tying into existing systems without disrupting the parts of the house you’re still living in.
What about gas lines for ranges, fireplaces, and outdoor kitchens?
We run and test gas piping for ranges, cooktops, gas fireplaces, tankless water heaters, grills, and generators. Every line is pressure tested and permitted, because a gas line is not a place to be casual.
Do you install the fixtures at the end too?
Yes — trim-out is ours as well. Faucets, toilets, tubs, showers, sinks, disposals, water heaters, and hose bibs installed, tested, and walked through with you or the builder before final inspection.
Recommended by your neighbors.
“My cost was exactly what he told me over the phone. He was on time, cleaned up after the repair and was very courteous. Hard Knox Plumbing will always be my first call.”
“As I expected, my call was answered by someone who actually knew what my problem was. Danny was able to work me in today.”
“It was an amazing service. They were on time, on budget and great to work with. Very knowledgeable, very friendly, and a reasonable price.”
From the blog
Straight answers on maintenance & seasonal tips.
Related Services
Related plumbing services.
Tankless Water Heaters
Endless hot water, lower energy bills, and a 20+ year lifespan.
Learn more →Fixture Repair & Replacement
Faucets, toilets, sinks, and disposals repaired or upgraded cleanly.
Learn more →Water Filtration Systems
Softer, cleaner water at every tap — and less scale in your pipes.
Learn more →Local, Licensed, On Schedule
A plumbing partner for East Tennessee builds.
Hard Knox Plumbing is locally owned, based at 3414 Henson Rd C, Knoxville, TN 37921, and led by Danny Ferris and Jarrett Mohn with a team of 7. We take on new construction, additions, and full remodels across Knoxville, Farragut, Hardin Valley, Lenoir City, Oak Ridge, Loudon, Alcoa, and Maryville.
Call 865.765.8946 — a real person answers 24/7, including nights, weekends, and holidays.
Project on a clock?
Call and get a real answer on availability.
Tell us your rough-in window and we’ll tell you straight whether we can hit it. No hedging, no maybes.