Do I need a permit for a full bathroom remodel in
Collierville, Tennessee?

Collierville full bathroom remodel permits — the key details

Collierville Building Department requires a permit for any bathroom remodel that involves fixture relocation, electrical work, ventilation changes, or structural alterations. The threshold is straightforward: if you're moving a toilet, sink, shower, or tub to a different location, that triggers a plumbing permit because you must verify trap-arm slope (IRC P3005.1 limits trap arm length based on the trap size and vent distance—typically 3 feet for a 1.5-inch line), re-vent the fixture properly, and ensure the new drain line meets the 18-inch frost-depth requirement for Collierville's zone (frost line matters for any below-grade or exterior penetrations). If you're adding a new circuit for heated flooring, a GFCI-protected outlet, or a bathroom exhaust fan, that's an electrical permit. If you're converting a tub to a shower (or vice versa), that requires a separate waterproofing plan review because the assembly changes—you'll need to submit specs for the shower pan membrane, cement-board substrate, and grout/sealant system per IRC R702.4.2, and inspectors will verify compliance before drywall closure. Even if you're just replacing tile and a vanity in the same footprint, you don't need a permit, but you do need to understand that any structural work—removing a wall, relocating the vent stack, raising the ceiling—requires framing and ventilation permits. Collierville's online portal lets you upload a scope summary before formal submission; use that free pre-screening step to clarify what you must permit and what you can DIY without review.

Plumbing code in Collierville follows the International Plumbing Code as adopted by Tennessee. The most common rejection point is improper vent design: if you're relocating a toilet, sink, or shower drain, the vent must be sized per IRC Table P3101.1 (typically 1.5 inches for a toilet, 1.25 inches for a sink or shower), and it must be pitched upward at no less than 1/4 inch per foot to prevent trap seal loss. The vent must also terminate above the roof (minimum 12 inches above the highest point within 10 feet horizontally per IRC P3103.2), which in Collierville often means coordinating with roofers or ensuring you don't trap moisture in an attic space—karst limestone areas are prone to humid basements and attics, and improper venting will cause mold and warranty callbacks. Second-most-common rejection: trap-arm slope. If you're relocating a bathroom sink or shower drain, the distance from the trap weir to the vent cannot exceed 3 feet (for 1.5-inch line) or 5 feet (for 2-inch line); if it does, you'll need to add a separate vent or re-vent the fixture, which adds cost and complexity. Inspectors in Collierville specifically ask to see trap-arm length on the plumbing plan, so measure and mark it clearly. Third issue: backwater valves. If your bathroom is on a basement floor or near grade (common in Collierville due to expansive soils and poor drainage), the city may require a backwater valve on the main drain to prevent sewer gas intrusion and sewage backup; factor in a $400–$800 cost if this applies.

Electrical code requires GFCI protection on all 20-amp receptacles in bathrooms per NEC 210.8(B), and AFCI protection on bedroom circuits if the bathroom is part of a master suite. If you're adding any new circuit—for a heated floor, an outlet, a light fixture, or the exhaust fan—that's a separate electrical permit. Your electrician must submit a one-line diagram showing the new circuit, breaker size, wire gauge, and GFCI/AFCI protection. Collierville inspectors will verify that 14 AWG or 12 AWG wire is used (no smaller) and that junction boxes are accessible. The exhaust fan is a frequent issue: if you're installing a new fan or relocating an existing one, you must show the duct routing on your electrical or mechanical plan—specifically, that it terminates outdoors (not into the attic, not into a soffit), with a damper to prevent backflow, and at least 6 inches clear of any soffit or fascia per IRC M1505.2. Duct diameter must match the fan rating (typically 4 or 6 inches); undersized ducts reduce airflow and cause condensation. If the ductwork runs through an unconditioned attic, you must insulate it to prevent condensation pooling. Collierville's humid subtropical climate (4A/3A zones) means bathroom moisture is a major issue—improper exhaust ducting leads to attic rot and mold, and inspectors take ventilation seriously.

Waterproofing is the gating item for any tub-to-shower conversion or new-shower installation. IRC R702.4.2 requires a vapor-permeable membrane under the tile and over the framing, plus a waterproof or water-resistant backing board (cement board, specialty boards like Durock or Schluter, or mortar-bed assembly). You must submit a section detail showing the assembly: subfloor, rough plumbing (if under-floor drain), substrate (cement board with minimum 1/4-inch thickness), membrane (liquid-applied or sheet membrane with sealed joints and penetrations), tile, and grout/sealant. Collierville inspectors will ask you to specify which membrane product you're using (e.g., Redgard, Hydro Ban, Schluter-Kerdi)—generic 'waterproof tape' is rejected. If you're installing a pre-fabricated shower pan, you must detail how the pan connects to the waste outlet, how the pan lip is integrated with the wall framing, and how the transition from pan to tile is sealed. Failure to detail waterproofing leads to a mandatory re-submit; plan an extra 1–2 weeks if this is your first time. One pro tip: have your tile contractor or a waterproofing supplier pre-stamp or initial the waterproofing detail on your plan; that gives inspectors confidence the assembly is actually achievable.

Timeline and practical next steps: Collierville accepts online submissions via its permit portal; you'll upload your scope summary, architectural/plumbing/electrical plans, and contractor info. Plan review takes 3–4 weeks for a standard full bathroom remodel (non-expedited). If you have a rejected detail, resubmit takes another 1–2 weeks. Once your permit is issued (fee: $300–$700 depending on project valuation, typically 1–1.5% of the remodel cost), you'll schedule rough plumbing and rough electrical inspections before drywall closure, then framing inspection (if walls moved), then drywall/waterproofing inspection (for shower pan and membrane), and final inspection once fixtures are installed and caulked. Budget 4–6 weeks total from permit issuance to final approval if you have no rejections. If you're an owner-builder (owner-occupied property only), you can pull the permit yourself and hire licensed plumbers/electricians for those portions; you must be present at each inspection. Collierville requires a current Tennessee license for any plumber or electrician doing permitted work, so verify your contractor's license before signing the contract—the city will reject the permit if the contractor is not properly licensed.

Three Collierville bathroom remodel (full) scenarios

Collierville's aggressive moisture control standard and why your exhaust fan matters

Collierville sits at the border between IECC climate zones 3A (humid subtropical, east side) and 4A (mixed humid, west side), and both zones experience high humidity and frequent moisture intrusion. The city's underlying karst limestone geology and expansive-clay soil profile mean that groundwater and vapor drive into basements and crawl spaces readily, and any bathroom that isn't properly vented will contribute to attic rot, mold, and structural damage. IRC M1505.2 requires bathroom exhaust fans to run continuously during bathing and for at least 20 minutes after (many builders use timers or motion sensors), and the duct must terminate outdoors—not in the attic, not in a soffit, not through a ridge vent. Collierville inspectors are strict about this because they've seen too many homes with black mold in attics caused by improper fan venting.

If you're installing a new exhaust fan or relocating an existing one, plan for 4-inch or 6-inch rigid ductwork (not flex duct, which collapses and traps moisture), properly insulated if it runs through unconditioned space, and a damper at the exterior termination to prevent backflow from wind. Soffit vents are not acceptable—duct must exit through the roof or gable wall. Many Collierville homes built in the 1990s–2000s have flex ducts vented into attics, which is why those attics now have mold; don't replicate that mistake. The permit plan must show duct size, routing, insulation, and exterior termination point; inspectors will verify this during rough-in and before any drywall closure.

Waterproofing specs and why Collierville doesn't accept shortcuts

Collierville Building Department requires explicit waterproofing design for any new or relocated shower or tub installation, and the spec must name a product and detail the assembly. Generic 'waterproof drywall' or 'cement board and caulk' gets rejected because those materials alone don't meet IRC R702.4.2, which calls for a continuous, sealed membrane over a water-resistant backing board. The approved approach is: (1) framing with blocking for grab bars and fixtures, (2) cement board or specialty board (Durock, Schluter, HardieBacker, or equivalent) fastened with corrosion-resistant fasteners at 8-inch centers, (3) a liquid-applied membrane (Redgard, Hydro Ban, Schluter Kerdi) or sheet membrane (Schluter Kerdi sheet, Wedi Waterproofing) applied per manufacturer specs with sealed corners and penetrations, (4) tile and grout, and (5) caulk or sealant at all movement joints.

The detail must be drawn to scale on your plan, showing the cross-section from subfloor through tile, and you must specify the membrane product by name. Many first-time remodelers assume that mortar-bed or mud-bed assembly (old-school thick mud over lath) is still acceptable—it is, per code, but Collierville doesn't see it often and inspectors want to verify the mud depth (minimum 1.5 inches) and slope (1/4 inch per foot to drain). If you're uncertain, use a modern liquid-applied membrane; it's easier to detail and faster to inspect. Cost difference is minimal (membrane adds $2–$5 per square foot, negligible in a total bathroom budget), and you'll pass inspection on the first submission instead of being rejected for vague specs.

Common questions