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Based in Carrollton · Serving the DFW Metroplex

Bathroom Remodeling, done right by DFW's remodeling team.

A DFW bathroom remodel starts under the floor — not with tile. Cast iron drain replacement, bonded-membrane shower pans on shifting clay, and every finish under one contract.

n a 1980s DFW home, the bathroom drain lines run through cast iron buried under the slab, the shower pan sits on clay that has been moving for 40 years, and the electrical runs on a single shared circuit that cannot meet current NEC requirements. None of these are cosmetic problems, and none of them can be patched after the tile is in.

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The Starting Point

The 1980s Builder-Grade Starting Point

Granite Guyz has walked hundreds of these bathrooms. The scene is the same in nearly every DFW home built between 1978 and 1995. A 30-inch vanity at countertop height. A one-piece fiberglass tub/shower combo that flexes under weight and has hairline cracks around the drain. A single Hollywood light bar above the mirror. Sheet vinyl on the floor. A 3.5-gallon toilet. A single 15-amp circuit shared with the bedroom and no GFCI protection anywhere in the room.

These materials were the cheapest the builder could spec at the time. The plumbing was the minimum the code required in the early 1980s. That was 40 years ago. None of it was built to last — it was built to close escrow.

A bathroom remodel in DFW does not start by choosing tile. It starts by understanding what that 1980s builder left behind and what needs to be replaced before any finish material goes in. That assessment is what Granite Guyz does on every walkthrough — checking the drain lines, the slab, the electrical, and the plumbing supply before a scope of work is written.

  • 30-inch single-sink vanity at 30-inch height with laminate top and builder-grade chrome faucet

  • One-piece fiberglass tub/shower combo — yellowed, flexes under weight, hairline cracks around the drain

  • Single Hollywood light bar above the mirror. No sconces, no dimmer, no wet-rated shower lighting

  • Exhaust fan undersized, vented into the attic instead of to the exterior, or missing entirely

  • 4×4 ceramic tile in beige, pink, or light blue. Grout re-caulked a dozen times and still leaks at the tub surround

  • Sheet vinyl or carpet on the floor. No uncoupling membrane. No waterproofing under the tub

  • Single 15-amp circuit shared with the bedroom — no GFCI, no AFCI, no dedicated bathroom capacity

  • 3.5-gallon toilet — nearly three times the water of a current code-required 1.28-gallon model

A bathroom remodel in DFW does not start by choosing tile. It starts by understanding what that 1980s builder left behind — and what needs to be replaced before any finish material goes in.

Under the Slab

Cast Iron Drains: What's Down There

In a DFW home built in the 1980s, the bathroom drain lines run through cast iron pipe buried in the soil beneath the slab. That cast iron has been in the ground for 40 years. Granite Guyz strongly recommends a camera scope of drain lines on every pre-1990 DFW project. Scale buildup, root intrusion, and pinhole corrosion are not visible during a standard home inspection — only the camera reveals them. Discovering a corroded drain line after demo is complete is a mid-project change order. Discovering it during pre-construction allows it to be priced as a scope item.

The three failure modes below each appear on Granite Guyz camera scopes regularly. They are not exceptional — they are expected in a 40-year-old cast iron system buried in DFW clay. What makes them structurally important is that each one feeds back into the clay expansion cycle beneath the foundation. A drain that leaks moisture into the soil is not just a plumbing problem. It is accelerating the differential slab movement that makes every other trade in the bathroom fail faster.

The camera scope costs $200–$400. Discovering corroded drain lines during pre-construction versus discovering them mid-demo saves the homeowner the cost of emergency scheduling, slab cutting under a finished floor, and disruption to adjacent work. There is no scenario where skipping the camera scope is the right decision in a pre-1990 DFW home.

Failure Mode 01

Scale Buildup

White and tan mineral deposits narrow the pipe’s interior diameter over decades. Flow slows. Backups become frequent. Visible on camera scope as white/tan buildup narrowing the pipe bore. Not visible on any standard home inspection.

Failure Mode 02

Root Intrusion

Hair-like fiber roots enter at joint cracks, accumulate organic material, and eventually block flow entirely. Roots follow moisture. Cast iron joints in 40-year-old DFW homes are the first place moisture escapes — and the first place roots find it.

Failure Mode 03

Pinhole Corrosion

Thin sections and pinholes in the pipe wall allow moisture into the surrounding soil. That moisture swells the DFW clay, lifts one section of the slab, while the adjacent dry section stays put — creating the differential movement that cracks slabs and widens drain joints further.

Method A — Most Common
Interior Access

Slab Cut

Cut the concrete slab along the drain path. Remove the cast iron. Route new PVC drain lines at proper slope to the main waste line. Backfill with clean sand. Patch and finish the slab.

This is the most common method for bathroom remodels where the entire floor is being replaced anyway. The cut is made, the work is done, and the slab patch is hidden under the new tile installation.

Method B — Minimal Disruption
Exterior Access

Tunnel

For isolated failing sections or when preserving the slab surface is critical, a tunneling crew excavates beneath the foundation from the exterior and replaces the pipe without cutting the interior slab.

Costs more than slab cut, but avoids disruption in areas outside the remodel zone. Used when only one section is failing and the homeowner is not replacing the floor in that area.

📷

Camera Scope Before Every Pre-1990 Project

Granite Guyz strongly recommends a camera scope on any DFW home built before 1990. Scale, root intrusion, and pinhole corrosion are not visible during a standard home inspection. Only the camera reveals them. For homes built before 1990, the camera is insurance against a mid-project change order discovered after demo begins.

$200–400
Camera scope cost vs. $15K+ blind drain replacement
Waterproofing System

Shower Pan Engineering on DFW Clay

Traditional mortar-bed shower pans work well on stable substrates. In DFW, the substrate is not stable. The montmorillonite and bentonite clay beneath the slab swells and shrinks with seasonal moisture changes — every wet spring, every dry summer. That movement transfers through the slab into the mortar bed. Over time, the mortar cracks at the curb, at the drain flange, and at the wall-to-floor transition. Water finds those cracks. Not in a catastrophic leak visible on the ceiling below — but as a slow seep that migrates into the clay beneath the slab and feeds the expansion cycle all over again.

Granite Guyz installs bonded waterproof membrane systems on every shower in the DFW Metroplex. Because the membrane is bonded to the substrate rather than floating over it, it moves with the substrate instead of bridging over cracks and tearing. That is the entire engineering argument: bonded vs. floating is the difference between a shower pan that lasts 25 years and one that fails in 5.

The flood test is not optional. Every shower installed by Granite Guyz is flood-tested — dam plugged, filled to the curb height for a minimum of 24 hours — before a single tile is set. If the membrane leaks at any transition point, it is fixed before the tile covers it. There is no alternative workflow.

  • Schluter KERDI

  • Laticrete Hydro Ban

  • TCNA Standards

  • 72″ min wall coverage

  • Flood test on every install

Top Layer
Tile & Grout

The finish layer. Installed over the membrane, not the substrate. TCNA Handbook setting standards throughout — large-format tile on a level, properly waterproofed surface.

Layer 5
Wall Membrane

Bonded membrane extends up shower walls to minimum 72 inches. Applied over cement board (Hardiebacker or Durock) — not drywall, not greenboard.

Layer 4
Curb Wrap

Shower curb wrapped on top and both sides, lapped onto floor and wall membrane. Every seam sealed. The curb is where most DFW shower pan failures originate.

Layer 3
Drain Flange Integration

Membrane ties into a bonding-flange drain — watertight connection at the lowest point where most mortar-bed systems fail first.

Layer 2
Bonded Membrane

Moves with the DFW slab instead of bridging over cracks. The key advantage on expansive clay — bonded vs. floating is the entire engineering argument for why Granite Guyz uses it on every DFW shower.

Base
Pre-Slope

Slab or mortar bed sloped at ¼ inch per foot toward drain. Water that reaches the membrane surface flows to the drain instead of pooling under it.

Trade Details

Tile & Plumbing Supply

The Finish That Depends on Everything Below It

Tile on a DFW Slab

On a DFW slab that has been leveled and waterproofed properly, tile performs well for decades. On a slab that was not leveled, large-format tiles crack at the edges and grout lines open within the first year. Granite Guyz follows TCNA Handbook standards for every installation — starting with the substrate survey before any tile is ordered.

On bathroom floors where slab movement is a concern, Granite Guyz installs an uncoupling membrane (Schluter DITRA or equivalent) between the slab and the tile. The membrane absorbs minor substrate movement without transferring it into the tile. This is standard practice on DFW clay — not an upsell.

Thin-set selection is also critical. Modified thin-set for bonding tile to the uncoupling membrane. Unmodified thin-set between the uncoupling membrane and the substrate. Using the wrong thin-set on the wrong layer is one of the most common — and most preventable — tile failures in the industry.

ANSI A108.02 Flatness Standard

No more than ⅛ inch of variation over 10 feet for tiles with any edge longer than 15 inches. A 40-year DFW slab will not meet this standard without a floor elevation survey and leveling intervention. Granite Guyz runs the survey before any tile is ordered.

What's Inside the Walls

Supply Line Replacement

The drain lines get the most attention, but supply lines in a 1980s DFW bathroom need evaluation too. Homes built mid-1980s through mid-1990s commonly have polybutylene supply lines — gray plastic pipe marketed as the future of residential plumbing that turned out to react with oxidants in the water supply and degrade from the inside out.

Polybutylene looks fine on the exterior while interior walls are flaking apart. It fails without warning at a fitting or joint behind the wall. If the walls are open for a remodel, that is the time to replace them. Waiting until after the tile is installed means tearing into finished walls to fix a known problem that could have been addressed for a fraction of the cost while the demo was already done.

Replace
Polybutylene
  • ✗
    Degrades from inside out
  • ✗
    Fails without visible warning
  • ✗
    Common in 1984–1995 DFW builds
  • ✗
    Class action history; insurer flags
Install
PEX
  • ✓
    Flexible, resists scale buildup
  • ✓
    Handles freeze-thaw cycles
  • ✓
    25+ year track record in DFW
  • ✓
    Installed while walls are open

Shower valves get upgraded at the same time. Original 1980s pressure-balance valves have no temperature limit stop. Modern pressure-balance valves include anti-scald protection. Thermostatic valves offer precise temperature control — required for any shower with multiple outlets such as body sprays, rain head, and handheld.

Code Compliance

Electrical & Ventilation

A 1980s DFW bathroom typically runs on a single 15-amp circuit shared with the adjacent bedroom. No GFCI. No AFCI. No dedicated bathroom capacity. Granite Guyz upgrades every bathroom to current NEC and IRC standards as part of a full remodel — not as an optional add-on. The cost of doing this electrical work is built into the scope from the beginning, because the alternative is doing it later at significantly higher cost after tile is in.

The single most neglected issue in 1980s DFW bathrooms is the exhaust fan — or more accurately, the way it was installed. Standard practice in 1980s DFW construction was to duct the exhaust fan into the attic. This was code-acceptable at the time. What it does is dump humid bathroom air directly onto the roof sheathing and blown insulation. Over years of DFW’s humid spring seasons, this creates the conditions for mold growth behind the drywall and rot in the roof sheathing. Granite Guyz ducts every exhaust fan to the exterior as a standard scope item, not an upgrade.

20A
Dedicated GFCI circuit required by current NEC
50+
CFM minimum exhaust fan (IRC)

Venting the exhaust fan into the attic — common in 1980s DFW builds — dumps humid air onto the roof sheathing and blown insulation. Granite Guyz ducts every exhaust fan to the exterior. In DFW’s humid spring months, that exhaust fan is the difference between a bathroom that dries out and one that grows mold behind the drywall within 5 to 8 years.

✓

At least one dedicated 20-amp GFCI-protected circuit for bathroom receptacles

✓

Wet-rated, IC-rated recessed lighting in the shower area — required for any fixture within the shower zone

✓

AFCI protection on bathroom branch circuits per current NEC cycle

✓

A dedicated or shared circuit for the exhaust fan — properly sized and ducted to exterior, not attic

✓

Dedicated circuit for electric heated floor mat if included in scope — pre-wired during rough-in

✓

Minimum 50 CFM intermittent or 20 CFM continuous ventilation (IRC) — ducted to exterior

✓

All rough-in inspected before walls close — plumbing pressure test, electrical rough-in, framing

After the Infrastructure

Vanities, Fixtures, & Layout

Once plumbing, electrical, waterproofing, and tile substrate work is complete and inspected, the finish phase defines the room. Every item below is an upgrade from the 1980s builder-grade baseline — not a cosmetic choice, but a functional and code-compliant improvement that reflects how the room will actually be used for the next 20 to 30 years.

Millwork
Vanity

30-inch single-sink at 30 inches replaced with 48–72 inch double-sink at 36-inch comfort height. Quartz tops for durability and low maintenance. Undermount sinks with single-hole faucets. Floating vanities gaining ground for a cleaner look and easier floor cleaning around the base.

From 30″ single to 72″ double
Enclosure
Walk-In Shower

Fiberglass tub/shower combo replaced with a tiled walk-in shower with frameless glass enclosure — the most requested upgrade in DFW master bath remodels. Curbless (zero-threshold) option where drain placement and floor slope allow. Meets ADA guidelines for aging-in-place, which adds resale value on top of daily usability.

Fiberglass combo out, tiled shower in
Optional
Freestanding Tub

Some master bath layouts include a freestanding soaking tub in addition to the walk-in shower. Requires a dedicated drain and supply rough-in at the tub location — Granite Guyz roughs this in during the plumbing phase, before the slab is patched. Attempting to add this after the slab is closed requires cutting the slab again.

Roughed in before slab patch
Fixtures
Toilet & Hardware

Original 3.5-gallon toilet replaced with a 1.28-gallon high-efficiency model — code requirement for new installations in most DFW municipalities. Same performance, less than half the water per flush. Towel bars, paper holders, and accessories spec’d during pre-construction so finish selections arrive before the relevant trade needs them.

3.5 GPF → 1.28 GPF (code required)
Lighting
Lighting Plan

Recessed LED cans (wet-rated in shower zone) replace the single Hollywood light bar. Vanity sconces on each side of the mirror provide even facial lighting that eliminates the shadow problems a single overhead bar creates. Every lighting circuit on a dimmer. Task, ambient, and shower lighting on separate switches for independent control.

Hollywood bar out, layered lighting in
Contract
One Scope

Every trade above — drain scope, demo, drain replacement, rough-in, waterproofing, tile, vanity, fixtures, and lighting — coordinated under the same project manager and schedule. The tile setter is not waiting on the plumber. The vanity installer is not waiting on the electrician.

Infrastructure through punch list
Transparent Pricing

What a DFW Bathroom Remodel Costs

Bathroom remodel pricing depends on scope. Labor accounts for 40% to 65% of the total project cost in DFW — skilled tile setters, licensed plumbers, and licensed electricians drive bathroom remodel pricing. Granite Guyz does not reduce trade quality because the trades are the project. The tile is what you see at the end, but what keeps it performing for 25 years is everything that was done before it was set.

Granite Guyz does not quote a bathroom from a photo. We scope it from the infrastructure up — elevation check on the slab, circuit test on the electrical, and for any home built before 1990, a camera scope of the cast iron drains. Then we price it in writing.

1
Cosmetic Refresh

New vanity top, faucet, mirror, lighting, paint, and hardware on the existing layout. No plumbing or electrical changes. Surfaces only. Best for bathrooms with sound infrastructure that simply need updated finishes.

$8K–$16K+
Existing layout stays
1
Midrange Full Remodel

Full demo, new tile floor and walls, new vanity, bonded-membrane shower with waterproofing, plumbing fixture upgrades including anti-scald valve, dedicated GFCI electrical circuit, and exterior-ducted exhaust fan. Same layout.

$28K–$45K+
Full scope — existing footprint
1
High-End Gut Remodel

Everything above plus cast iron drain replacement, plumbing relocation for new fixture positions, curbless shower with frameless glass, freestanding tub, heated floors, custom vanity, and premium finishes throughout.

$45K–$75K+
New layout + new infrastructure

Cast iron drain replacement (add-on): When the camera scope reveals corroded drains, replacement is added to the remodel scope — not discovered as a change order mid-demo. Cost depends on scope and method (slab cut vs. tunnel) and how many drain lines are affected.

$9K–$28K
Add-on cost

Every project carries a 10% to 15% contingency. In a 40-year-old DFW bathroom, the demo always reveals something. Rotted subfloor around the toilet flange. A drain section the camera could not fully scope. Mold behind the fiberglass tub surround. Wiring that does not match the panel schedule. Granite Guyz documents every discovery and requires written authorization before additional work begins — nothing is added to scope verbally.

10–15%
The Renovation Sequence

The Bathroom Remodel Sequence

A bathroom remodel runs in a specific order. Each step depends on the one before it. Granite Guyz coordinates every trade so the plumber is not waiting on the electrician and the tile setter is not waiting on the plumber. This is the sequence on every project — and every inspection point is a non-negotiable gate before the next phase begins.

  • Pre-Construction

    Drain camera scope (required on all pre-1990 homes), scope of work, permit applications, material selections, and fixture orders. All decisions locked before demo starts. Lead times for custom vanities and specialty tile are confirmed at this stage.

  • Demolition

    Remove all fixtures, tile, vanity, tub/shower, flooring, and drywall as needed. Expose framing, plumbing, and electrical for inspection. Demo reveals what the walls were hiding — and what the camera scope may not have captured fully.

  • Drain Replacement

    Cut slab or tunnel for cast iron replacement if camera scope indicates failing pipe. Route new PVC drains at proper slope. Backfill with clean sand. Patch and finish slab.

  • MEP Rough-In

    Plumbing supply lines (PEX replacement, new valve locations, freestanding tub rough-in if applicable), Electrical (20-amp GFCI circuit, recessed lighting, exhaust fan to exterior, heated floor mat pre-wire), and structural framing for niche or layout changes.

  • Inspections

    Plumbing rough-in (pressure test), electrical rough-in, and framing inspection. Walls do not close until all three pass. The permit record is the permanent documentation of what is inside the walls — and what will be disclosed at resale.

  • Substrate & Waterproofing

    Cement board on walls. Slab leveling on floors. Shower pre-slope, bonded waterproof membrane, drain flange integration, curb wrap. Flood test at 24 hours minimum before any tile is installed.

  • Tile

    Floor tile on uncoupling membrane. Wall tile on bonded membrane. TCNA Handbook setting standards throughout. Grout and seal after inspection of tile layout, coverage, and lippage.

  • Vanity & Fixtures

    Set vanity, countertop, sinks, faucets, toilet, shower glass, mirrors, and accessories. Every fixture trimmed and tested — water run, valves checked, fan confirmed to exterior — before final walkthrough is scheduled.

  • Final Inspection & Punch List

    Municipal final inspections passed. Homeowner walkthrough with project manager. Punch list documented and closed out before the project is considered complete.

A midrange full remodel typically runs 4 to 8 weeks from permit pull to punch list. High-end gut remodels with cast iron replacement and layout changes run 8 to 14 weeks. Pre-construction selections and permit review add 2 to 4 weeks before construction begins.

Where We Work

DFW Bathroom Service Areas

Granite Guyz remodels bathrooms across six DFW municipalities. Each city has its own building department, permit timeline, and housing stock profile. Each guide below adds city-specific context to the scope covered on this page.

Carrollton
Building Inspections — 24–48 hr permits

Dense concentration of 1970s–90s homes with original cast iron drain lines. Polybutylene supply lines common. High demand for full infrastructure-up remodels.

  • Prestonwood

  • Old Town

  • Josey Ranch

Dallas
Dallas Development Services — 3–5 day review

Wide range from 1940s post-war builds to 1980s Far North Dallas. Older homes often have galvanized supply lines in addition to polybutylene. Historic overlay districts add review steps.

  • East Dallas

  • Lake Highlands

  • Preston Hollow

Plano
Plano Building Inspections — 2–3 day permits

Predominantly 1980s–90s suburban housing. Master bath additions and luxury upgrades are the most common scope. HOA review required in most planned communities.

  • West Plano

  • Haggard Estates

  • Legacy

Frisco
Frisco Development Services — 2–4 day review

Newer construction (1995–2010) with active HOAs and strong demand for spa-style master bath upgrades. Polybutylene less common but PVC drain systems still age. HOA approvals required.

  • Stonebriar

  • Panther Creek

  • The Hills

Richardson
Richardson Building Services — 24–48 hr permits

Heavy concentration of 1960s–80s homes near the Telecom Corridor. Original galvanized and cast iron plumbing common in pre-1975 builds. Slab settlement requires elevation survey before every project.

  • Canyon Creek

  • Northrich

  • Spring Creek

Addison
Addison Building Dept. — 1–2 day permits

Dense residential pockets with 1970s–80s housing stock. Small lot sizes and compact bathroom footprints. Full remodels stay within existing footprint in most cases.

  • North Addison

  • Quorum District

Granite Guyz does not quote a bathroom remodel from a photo. We scope it from the infrastructure up — elevation check on the slab, circuit test on the electrical, and for any home built before 1990, a camera scope of the cast iron drains. Call (214) 808-4829 to schedule a bathroom walkthrough.

Frequently Asked Questions

Bathroom Remodel Questions DFW Homeowners Ask

Get a Real Answer

We scope bathrooms from the infrastructure up — slab elevation, electrical circuit check, and camera scope on pre-1990 drain lines. What we find determines what the project costs.