Blog > Solid from the Start: How to Prep Your Shower Subfloor for Long-Lasting Tile in PA

Solid from the Start: How to Prep Your Shower Subfloor for Long-Lasting Tile in PA

Monday, August 04, 2025

Start Your Shower Right—From the Ground Up

When it comes to building a beautiful, long-lasting tile shower, it’s easy to get excited about the design—tile patterns, grout colors, and hardware finishes. But at Nolt’s Floor Covering, we know the real secret to a shower that holds up for years: a properly prepped subfloor with solid waterproofing and a level foundation.

Homeowners from Ephrata to Myerstown trust us because we don’t cut corners, especially when it comes to what’s underneath. That’s where durability starts.

Let’s walk through how to make sure your tile shower doesn’t just look amazing, it’s functional and watertight.

Why Subfloor Prep Is So Important

Moisture is the enemy of long-term tile success—especially in a shower. If your floor isn’t level or properly sealed, water will find its way through grout lines, around drains, and into the subfloor. Once that happens, you’re at risk for:

• Mold and mildew
• Soft or sagging spots
• Cracked or popping tiles
• Expensive repairs down the road

We once worked on a home in Mohnton where a DIY shower install had been done just two years earlier. The tile looked fine on the surface, but water had crept into the seams, and the plywood underneath was saturated and starting to buckle. Our crew had to tear everything out, bring in a framing contractor then re-level the floor, install a waterproof membrane, and then re-tile—costing the homeowner far more than it should have.

Step 1: Check Your Subfloor Surface

Before we install any tile, we always start with a close inspection of the subfloor:

• Is it dry and free of mold or damage?
• Are there any dips, humps, or uneven seams?
• Is the surface clean and free of debris or construction dust?

If it’s a wood subfloor, we make sure it’s solid and free of movement, but we don’t rely on that wood alone to protect against water. That we will cover later.

Step 2: Get That Floor Flat

Why Leveling Matters for Tile Showers

Tile is rigid—so even a small dip or slope in your floor can cause lippage (uneven tile edges), cracking, or drainage issues. In a shower, we always ensure proper slope toward the drain, but the surrounding subfloor must also be level and stable.

How We Ensure a Level Surface:

• Self-leveling compound: We use this to fill low spots and create a smooth base for the shower pan or tile underlayment.
• Sanding or feathering high spots: To prevent any ridges from showing through the tile.
• Pre-sloped shower trays or mud pans: These ensure water flows directly to the drain without pooling.

For customers in areas like Denver, PA where we’ve worked in older homes with settled floors, this step is especially important. Even if things look flat to the eye, our estimators and installers use lasers and levels to double-check everything.

Step 3: Moisture Protection Is a Must

Why Just Cement Board Isn’t Enough

Many homeowners assume cement board is waterproof. It’s not! It’s moisture-resistant—but water can still seep through seams and screw holes if it’s not sealed properly.

At Nolt’s, we build every tiled shower with full waterproofing protection—because the best tile job in the world won’t last long without it.

Our Go-To Waterproofing Systems:

• Schluter Kerdi– Foam board or membrane systems that are fully waterproof and lightweight
• RedGard or liquid waterproofing membranes – Applied over cement board to create a seamless moisture barrier
• Seam tape and sealant – All joints, screw holes, and corners get sealed before tile goes down

We once had a customer in Myerstown who wanted to update their shower with porcelain tile but had concerns about mold from a past leak. We used a full Schluter Kerdi system on their new build and walked them through each layer of protection. They told us later, “I finally feel like I don’t have to worry every time someone showers!”

Step 4: Build on the Right Backer

Under the tile, we always install a tile backer board or foam board that’s built for wet areas.

Tile-Ready Backer Options:

• Cement board (like Durock or HardieBacker): Installed over the subfloor, then coated with waterproofing
• Schluter Ditra uncoupling membranes: Installed over the subfloor.
• Foam boards (like Kerdi-Board): Lightweight and already waterproof
• Waterproof sheet membranes: For use over cement board or mud pans

No matter what the system, our goal is the same: Keep water away from your wood subfloor at all costs.

Step 5: Seal the Deal

After waterproofing is complete and before tile goes in, we take extra care to:

• Double-check for pinholes, missed seams, or thin areas in the membrane
• Confirm proper slope toward the drain (especially in custom pans)
• Ensure corners and edges are fully sealed

This is the final step before the beautiful part—the tile itself.

Can You Do It Yourself? Maybe. But Here’s the Catch…

We love when homeowners want to be hands-on. But we’ve seen too many shower projects in Central PA go sideways because of skipped prep steps.

If you're even a little unsure about leveling, waterproofing, or using membranes—it's worth having a pro handle it. A small mistake can lead to thousands in damage.

Why Homeowners Trust Nolt’s Floor Covering

We’re a local, family-owned flooring and tile installer serving Ephrata, Myerstown, and surrounding Lancaster and Lebanon County communities. We treat your home like it’s our own and never take shortcuts, especially where water is involved.

When you work with Nolt’s, you get:

• A team that shows up on time and cleans up every day
• Expert craftsmanship and premium materials
• Honest advice with no pressure
• A bathroom that’s as functional as it is beautiful

Because at the end of the day, we’re all about “Making your flooring dreams come true!”

Ready to Start Your Shower Project? Let’s Talk.

We’d love to help you design and build a shower that’s solid from the ground up—and waterproof for years to come.

➡️ Stop by our showrooms in Ephrata or Myerstown to see all these options in person

📍 Ephrata, PA– 609 North State St., Ephrata PA 17522 (717) 733-5503

📍 Myerstown, PA– 400 West Lincoln Ave., Myerstown PA 17067 (717) 866-6186

➡️ Or schedule a free consultation — we’ll bring the samples to you!

Happy flooring – Nolt’s Floor Covering

Making your flooring dreams come true!