The Kentucky plumbing code requires almost all plumbing work in the state to be done by a licensed journeyman or master plumber, performed under a permit issued by the Department of Housing, Buildings and Construction (HBC), and cleared through staged inspections before it can be concealed or put into use. The Division of Plumbing inside HBC runs the licensing exams, reviews plans, issues permits, and sends inspectors to job sites for both residential and commercial work. Violating any part of the code exposes you to daily fines, jail time, and license action.
Who the Code Covers
The licensing requirement applies to anyone engaged in the plumbing trade.1Kentucky Legislative Research Commission. Kentucky Revised Statutes 318.020 – Apprentices, Maintenance Men, Water Company or District Employees Exempt You cannot work in plumbing without a valid journeyman or master license from HBC.2Department of Housing, Buildings and Construction. Frequently Asked Questions (Plumbing) The narrow exceptions are apprentices working under a licensed journeyman, maintenance workers, and employees of water companies, water districts, or sanitation districts working on their employer’s mains and infrastructure.
A plumbing business can only operate if a licensed master plumber is connected with the company, and the business has to tell HBC who that master plumber is. Employing anyone who isn’t a licensed plumber or a licensed apprentice is illegal.3Kentucky Legislative Research Commission. Kentucky Revised Statutes Chapter 318 – Plumbers and Plumbing
Getting Licensed
Two licenses do the work in Kentucky: journeyman and master. Each has its own experience floor and exam.
Journeyman Plumber
You need at least two consecutive years of experience as an apprentice plumber, or a department-approved plumbing course plus one year of apprentice experience. Either path leads to a written exam covering basic plumbing principles, KRS Chapter 318, and applicable regulations, together with a practical component that involves pipe sizing on a prepared drawing.4Kentucky Legislative Research Commission. 815 KAR 20:030 – Plumbing Licenses
The exam fee is $50 (nonrefundable). The license itself costs $60 after you pass.4Kentucky Legislative Research Commission. 815 KAR 20:030 – Plumbing Licenses
Master Plumber
To sit for the master exam, you must have held a valid journeyman license for at least two of the five years immediately before applying, and worked under a licensed master plumber during that period. The master exam covers the same subject areas as the journeyman exam at an advanced level.4Kentucky Legislative Research Commission. 815 KAR 20:030 – Plumbing Licenses
The master exam fee is $150. The license fee is $250. Master plumbers also have to carry proof of insurance under KRS 318.030.4Kentucky Legislative Research Commission. 815 KAR 20:030 – Plumbing Licenses
Renewal, Lapse, and Inactive Status
Renewal is $250 for a master and $60 for a journeyman, and requires proof of continuing education under 815 KAR 2:010. A lapsed license can be revived by paying the renewal fee plus a revival fee and showing completion of continuing education. If you want to step away for a while, you can place your license in inactive status; while inactive, you cannot pull permits, advertise as a licensed plumber, or perform plumbing work. Reactivation requires the standard renewal steps plus a reactivation fee.4Kentucky Legislative Research Commission. 815 KAR 20:030 – Plumbing Licenses
When You Can Do Your Own Plumbing
The code carves out a few situations where a licensed plumber isn’t required, but the work still has to meet code and be inspected.
Homeowner Exemption
If you own and occupy a home, or are building one for your own use, you can pull the plumbing permit yourself. The work still has to comply with the Kentucky State Plumbing Code and still gets inspected by the Division of Plumbing. What changes is that you don’t need to hire a licensed master plumber to get the permit.5Department of Housing, Buildings and Construction. Division of Plumbing The exemption does not reach rental properties, commercial buildings, or work on someone else’s house.
Farmstead Exemption
Agricultural buildings qualify for a farmstead exemption under KRS 318.015(3). The structure must be a dwelling or a building used in the operation and maintenance of the farm, like a barn or shed, and cannot be a commercial or public building. You file an affidavit with HBC confirming those conditions.6Department of Housing, Buildings and Construction. Affidavit for Farmstead Exemption
Manufactured Homes
Manufactured homes and mobile home parks follow separate installation standards under 815 KAR 25:090, which incorporates federal HUD requirements at 24 C.F.R. Part 3285 for site preparation, ground anchoring, and utility connections. Exterior plumbing connections for manufactured homes must meet the Kentucky Residential Code.7Kentucky Legislative Research Commission. 815 KAR 25:090 – Site Preparation, Installation, and Inspection Requirements
Permits and Plan Review
No one may construct, install, or alter any plumbing without first getting a permit from the Division of Plumbing.5Department of Housing, Buildings and Construction. Division of Plumbing Permits go only to licensed master plumbers or to homeowners working on their own residence. For buildings that serve the public, the Division reviews and approves construction plans before issuing the permit.8Kentucky Legislative Research Commission. 815 KAR 20:050 – Installation Permits Plan review looks at pipe sizing, fixture placement, drainage, and backflow prevention.
What Permits Cost
Fees depend on building type and the number of fixtures involved.8Kentucky Legislative Research Commission. 815 KAR 20:050 – Installation Permits
- One- and two-family residential: $50 base fee plus $14 per plumbing fixture, appliance, opening in the waste pipe system, domestic water heater, or separately metered water and sewer service.
- All other buildings (commercial, industrial, multi-family): $50 base fee plus $20 per fixture, appliance, opening in the waste pipe system, domestic water heater, conductor opening, or separately metered water and sewer service.
A small residential bathroom remodel with three fixtures runs about $92; a commercial restaurant kitchen with ten fixtures comes out around $250. The permit must be posted on site throughout construction.
Inspections
The Division inspects installations at multiple stages, and whoever pulled the permit is responsible for calling in each inspection. Concealing plumbing before it has been approved is one of the quickest ways to get shut down.9Legal Information Institute. Kentucky Code 815 KAR 20:150 – Inspection and Tests
The rough-in inspection happens before anything gets closed up inside walls or floors. Inspectors check pipe materials, connections, venting, drainage slopes, and water supply sizing, and pressure tests confirm the system holds without leaks. Deficiencies must be corrected and re-inspected before you cover the work.9Legal Information Institute. Kentucky Code 815 KAR 20:150 – Inspection and Tests Once installation is complete, you request a final inspection and air test, where inspectors verify drainage, water pressure, and backflow prevention, sometimes using dye or smoke tests to find hidden leaks or venting problems.
Common Failures
A few issues turn up again and again:
- Bathtub and shower valves without an access panel, so the inspector cannot reach the valve without cutting into a wall.
- Missing individual shut-off valves at sinks and toilets, which means a single fixture can’t be isolated from the rest of the building.
- S-traps used where P-traps are required. S-traps can siphon dry and admit sewer gas.
- Incorrect drainage slope, whether too flat (waste sits) or too steep (liquids outrun solids).
Backflow, Lead, and Accessibility
Three installation requirements deserve their own attention because they cut across most projects.
Backflow Prevention
Kentucky classifies cross-connections by hazard level and requires a matching device.10Kentucky Legislative Research Commission. 815 KAR 20:120 – Backflow Prevention
- Severe hazard (toxic substances or disease-causing organisms), such as hospitals, laboratories, cooling towers, and sewage treatment connections: a reduced pressure principle backflow preventer.
- Moderate hazard (nontoxic but objectionable substances), such as small boilers and dairy equipment: a backflow preventer with an intermediate atmospheric vent.
- Low hazard (generally nontoxic substances), such as commercial pools and food processing tanks: a double check valve assembly.
An air gap between the outlet and the flood-level rim is the preferred protection whenever it’s physically possible. Residential systems typically use simpler devices like vacuum breakers for irrigation and hose bibb connections.
Federal Lead-Free Rule
Every pipe, fitting, and fixture installed in Kentucky has to meet the Safe Drinking Water Act’s lead-free standard. Under Section 1417, wetted surfaces cannot exceed a weighted average of 0.25% lead, and solder and flux are capped at 0.2% lead.11Office of the Law Revision Counsel. 42 USC 300g-6 – Prohibition on Use of Lead Pipes, Solder, and Flux In practice that means keeping the manufacturer’s lead-free certification for the materials you install. Using non-compliant materials violates both Kentucky code and federal law.
ADA in Commercial Restrooms
Commercial restrooms have to comply with the Americans with Disabilities Act. Wheelchair-accessible stalls must be at least 60 inches wide, with the toilet centerline 16 to 18 inches from the side wall. Accessible sinks must have a rim no higher than 34 inches above the floor, at least 27 inches of knee clearance underneath, and a 30-by-48-inch clear floor space for wheelchair approach. Fixtures set at the wrong height or spacing fail inspection.
Penalties
Under KRS 318.990, violating any provision of Chapter 318, the administrative regulations, or the State Plumbing Code carries a fine of $10 to $100, up to 90 days in jail, or both. Each day the violation continues is a separate offense.12Justia. Kentucky Revised Statutes 318.990 – Penalties A two-week job run without a license can generate 14 separate violations.
HBC can also suspend or revoke a license through administrative action, and a business that employs unlicensed workers faces penalties under KRS 318.120.3Kentucky Legislative Research Commission. Kentucky Revised Statutes Chapter 318 – Plumbers and Plumbing Repeat offenders can lose the ability to pull permits at all.
Appealing a License Action
If HBC suspends or revokes your license, you’re entitled to a hearing under KRS Chapter 13B, the general administrative hearing statute. You can also ask the Division of Plumbing to reconsider before a formal hearing, backing the request with evidence like engineering reports or photographs showing code compliance.13Justia. Kentucky Revised Statutes 318.066 – Hearing, Appeal
If the department’s final order goes against you, appeal runs to the circuit court in the county where your principal office is located, following the procedures in KRS Chapter 13B.13Justia. Kentucky Revised Statutes 318.066 – Hearing, Appeal Documentation of alternative compliance methods or a professional engineering assessment strengthens the record at any stage.