Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Tamko Bathroom Remodeling: The Orange County Owner’s Guide
If you’re looking for Tamko bathroom remodeling in Orange County, the typical installed project runs $9,000 – $28,000 depending on the scope, the condition of your existing walls and subfloor, and whether you’re doing a like-for-like refresh or moving plumbing. We stock Tamko waterproofing and backer materials on our trucks for most standard applications, so we can usually start the tear-out within a week of your written estimate. Most Orange County homeowners call us after they’ve spotted cracked grout lines, a soft spot in the shower floor, or water staining on the ceiling below an upstairs bathroom, and by then the waterproofing layer behind the tile has already been compromised.
Let’s talk about what Tamko actually is in a bathroom, because there’s some confusion out there. Tamko is best known as a roofing manufacturer, but their composite waterproofing membranes and shower pan liners show up in a lot of bathrooms built in Orange County during the 1990s and early 2000s, especially in tract home developments across Irvine, Mission Viejo, Lake Forest, and Yorba Linda. When you’re remodeling one of those bathrooms, the first thing we check is whether the original Tamko pan is still doing its job or whether it’s been quietly leaking into the subfloor for years.
Which Tamko Bathroom Products This Applies To
In practice, when we talk about Tamko in a bathroom remodel, we’re talking about two main product categories: Tamko shower pan liners and Tamko waterproofing membranes used behind tile and under flooring. The shower pan liner is the flexible PVC sheet that sits under your mortar bed and directs any water that seeps through the grout down into the drain, rather than into your floor joists. The waterproofing membrane is the roll-on or sheet-applied barrier on walls and floors that keeps moisture out of the framing.
Here’s the compatibility gotcha most Orange County homeowners don’t know: Tamko shower pan liners come in 20-mil and 40-mil thicknesses, and the drain clamping ring has to match the liner thickness. If a previous installer paired a 40-mil liner with a drain assembly designed for 20-mil, the clamping ring won’t seat properly and water finds its way around it. We see this regularly in older Irvine homes near the Spectrum, where 1980s and 90s builds are hitting their second or third bathroom renovation. On OEM versus aftermarket: Tamko still sells their waterproofing products through plumbing supply houses in Southern California, but many quality aftermarket systems, like Schluter Kerdi and Wedi, exceed the original spec. For a remodel, we’ll match the better system to your situation and give you the reason in writing.
Styles & brands we work with
Signs Your Tamko Shower Pan or Waterproofing Is Failing
- Staining on the ceiling of the room below. This is the most common first sign in two-story Orange County homes. Water has breached the pan or the membrane and is pooling on the subfloor. The stain usually shows up near the drain or along the edge of the tub surround.
- A persistent musty smell you can’t locate. That’s water sitting behind tile, soaking into drywall or wood. The Tamko membrane has failed in a spot that isn’t visible, and the framed wall is staying damp.
- Cracked grout lines at the shower floor corners. Grout cracks where the floor meets the wall because the mortar bed underneath is shifting, which usually means the pan liner under the mortar has failed and the bed is no longer draining properly.
- Soft or spongy spots in the bathroom floor. If the subfloor around the toilet, tub, or shower flexes when you step on it, water has been soaking into the wood. By the time you feel it, the rot is usually worse than it looks.
- Efflorescence on the slab or floor below grade. White mineral deposits on concrete suggest water has been moving through it for a while. In slab-on-grade homes in Orange County, a failed shower pan is often the culprit.
Any one of these is worth a professional look. If you’re seeing two or more, the waterproofing has almost certainly failed and the repair is a remodel, not a patch.
Replacement Cost & What’s Included in Orange County
A full bathroom remodel involving Tamko waterproofing replacement runs $9,000 – $28,000 in Orange County. A smaller guest bath with a like-for-like layout and stock tile can land around $9,000 – $12,000. A master bath where you’re moving plumbing, adding a walk-in shower, and using full-height porcelain or natural stone can push toward $28,000. The table below gives you the main line items as we bid them.
| Scope | Typical Installed Range |
|---|---|
| Full bathroom remodel (labor, materials, waterproofing) | $9,000 – $28,000 |
| Small bathroom remodel (guest bath, standard finishes) | $5,000 – $12,000 |
| Walk-in shower installation (incl. new waterproofing system) | $4,500 – $12,000 |
| Tub-to-shower conversion | $3,500 – $10,000 |
| Shower replacement (pan and tile only) | $3,000 – $8,500 |
| Bathroom vanity installation | $800 – $3,000 |
What drives the range? Tile choice is the biggest swing. A porcelain tile from Emser or Daltile that costs $4 a square foot finishes very differently from a $20-per-foot marble. Then comes layout changes: keeping the toilet and shower where they are is way cheaper than moving a drain line. We use cement board substrate (the moisture-resistant layer behind your tile) on every wet wall, and we install a written waterproofing spec whether it’s a Tamko-compatible replacement or a newer membrane system. Every bid includes a written price before work starts, so the number on day one is the number on the invoice. And every project carries our 365-Day Done Right Promise in writing: if the work fails inside the guarantee period, we come back and fix it at no charge.
See the difference
Before
After
Before
After
Before
AfterDIY or Call Us?
Here’s the honest split. You can check a few things safely: look for ceiling stains under the bathroom, press on the floor around the toilet and tub for softness, and run a bead of water along the shower floor edges to see if grout soaks it up quickly. That tells you whether you have a problem. What we’d caution against is cutting into the pan or pulling tile to “see how bad it is” without a moisture assessment, because once you open a failed waterproofing layer, you’ve exposed the subfloor and the clock starts on permanent damage. Working with tile, mortar, and shower pan liners is physically demanding and easy to get wrong in ways that leak silently for years. If you’ve already found signs of water damage, call us at (424) 541-1701. We’ll give you the number first, then pick up the tool.
FAQs
A properly installed Tamko shower pan liner typically lasts 15 to 25 years in Orange County, though hard water and high humidity can shorten that. If your pan was installed before 2005 and the grout has been re-sealed a few times, it’s worth having the pan and membrane checked even if the tile still looks fine.
In almost every case, no. The pan liner sits under the mortar bed, so repairing it means removing the tile, the mortar, and the liner itself, then reinstalling the full waterproofing assembly. Patching grout or caulking seams is a temporary cosmetic fix, not a waterproofing repair. Call us at (424) 541-1701 and we’ll tell you honestly whether a patch will buy you time or whether a rebuild is the right call.
A standard guest bath in Orange County usually runs 2 to 3 weeks in our schedule. A master bath with custom tile work, heated floors, or plumbing moves can run 4 to 6 weeks. We’ll give you a written timeline with the written price, and we’ll tell you before we start if materials lead times affect it.
We stock Tamko shower pan liners and standard waterproofing membrane products commonly used in Orange County bathrooms, along with professional systems like Schluter and Wedi. We also source materials from recognized trade brands including KraftMaid for cabinetry, Cambria and Silestone for countertops, and Kohler and Moen for fixtures. If you want a specific brand or product, we’ll price it out and put it in the written estimate before you commit.
Ready to Fix the Bathroom the Right Way?
If your Tamko waterproofing has failed or you’re planning a bathroom remodel in Orange County, call Penhallow Remodeling Orange County at (424) 541-1701 for a free estimate. A live person answers 24/7, so you won’t get a voicemail maze. We’ll schedule a walkthrough, give you a written price before any work starts, and put the guarantee in writing. Background-checked, uniformed technicians on every job, and a defined arrival window you can plan around. Give us a call and we’ll make sure your bathroom is done right, from the waterproofing up.
Written by Trevor Nash, Owner, Penhallow Remodeling Orange County at Penhallow Remodeling Orange County, serving Orange County and nearby areas.
