Is PVC Shiplap Waterproof? The Complete Expert Guide to Using PVC Shiplap in Bathrooms

As a home improvement expert with over 15 years of experience in bathroom renovations and upgrades, I‘m often asked if PVC shiplap is a suitable option for bathrooms. With its affordable price point and ease of installation, it‘s understandable why many homeowners are drawn to PVC shiplap for their bathrooms. However, its water-resistance capabilities raise some valid concerns.

In this comprehensive guide, I‘ll share my professional insight on using PVC shiplap in bathroom installations. I‘ll cover everything from its advantages and disadvantages compared to other materials to step-by-step installation tips and creative ways to incorporate shiplap into shower surrounds. My goal is to provide homeowners like you with expert guidance to make informed decisions about PVC shiplap in bathrooms.

What is PVC Shiplap?

For those unfamiliar, PVC shiplap consists of tongue-and-groove panels made from polyvinyl chloride rather than solid wood. It provides the look of classic shiplap cladding in a lightweight, low-maintenance plastic material.

Here are the key features and benefits of PVC shiplap:

• Cost-effective – PVC shiplap panels cost 25-50% less than wood shiplap. This makes it an affordable option for many budgets.

• Easy installation – The lightweight panels are quick and straightforward for DIY installation. No special tools needed.

• Dimensional stability – The plastic material resists swelling, shrinking, cracking and warping. It maintains its form well.

• Range of finishes – From smooth to embossed wood grain textures. Stains and paints well for different looks.

• Moisture-resistance – PVC contains water-repelling properties that make it suitable for damp environments.

• Low maintenance – Unlike wood, it doesn‘t require sanding, staining or regular repainting. Just occasional cleaning.

Those benefits make PVC shiplap an appealing choice for bathrooms. However, there are some downsides to consider:

• Not as durable as wood – PVC is susceptible to dents, scratches and damage from impacts.

• Less authentic than real wood – The appearance, while nice, is clearly synthetic upon close inspection.

• Not inherently waterproof – Requires additional sealing for adequate water protection.

• Can show seams – Joints between panels are often more visible than with wood shiplap.

• Prone to expansion/contraction – Dimensional changes with temperature fluctuations can worsen seams.

• Can discolor over time – Prolonged sun/moisture exposure can cause fading or yellowing.

While PVC shiplap has many favorable attributes, its limitations are important to factor when deciding if it’s the right choice for your particular bathroom application.

Is PVC Shiplap Waterproof?

One of the most common questions surrounding PVC shiplap is whether or not it is truly waterproof. The short answer is no – PVC shiplap is water-resistant but not 100% waterproof.

The plastic material itself has water-repelling properties. However, PVC shiplap panels connect via tongue-and-groove channels that leave slight gaps along seams. Over time, these can loosen or separate entirely, allowing moisture seepage.

Constant humidity and condensation in bathrooms can eventually take its toll. Prolonged moisture exposure can cause PVC shiplap to swell, warp, discolor or delaminate. Mold and mildew growth is also a possibility.

Therefore, while PVC shiplap has decent natural moisture resistance, it requires supplemental protection to be considered waterproof. This is especially important for shower areas.

How to Waterproof PVC Shiplap for Bathroom Use

Based on my professional experience, here are my top recommendations for waterproofing PVC shiplap in bathroom installations:

1. Seal All Joints and Seams

Caulking provides the first line of defense against moisture. Be sure to:

• Seal all shiplap seams and corners with a flexible, mildew-resistant silicone caulk.

• Also caulk around windows, doors, plumbing fixtures, light fixtures, or any gaps.

• Apply caulk beads thick enough to fill the joints fully.

• Smooth the caulk with a finger or tool to evenly seal gaps.

2. Apply Waterproofing Membrane or Sealer

For added protection:

• Coat all shiplap with a waterproofing paint or membrane, like RedGard.

• Liquid sealers soak into seams to waterproof from the inside out.

• 2 full coats are recommended, allowing proper drying time between coats.

3. Use Moisture-Resistant Substrate

Instead of drywall, install panels over:

• Cementboard, Fiberock Aqua-Tough, or other bathroom-grade substrate.

• Water-resistant surfaces won‘t mold if moisture sneaks through seams.

4. Leave Room for Ventilation

Prevent moisture buildup by allowing airflow:

• Leave a 1/4" gap along ceiling and baseboards.

• Consider drilling weep holes along bottom panel edges.

• Install a bathroom ventilation fan if the room lacks windows.

Proper prep and installation techniques make all the difference in waterproofing PVC shiplap bathrooms. Be sure to closely follow the manufacturer’s instructions for your specific product.

Step-by-Step: Installing PVC Shiplap in Bathrooms

Here is an overview of the installation process based on techniques I use for bathroom shiplap projects:

1. Prep the Walls

• Remove existing finishes down to studs or masonry surface.
• Inspect for leaks – repair plumbing, seal concrete cracks, etc.
• Install cementboard, Fiberock, DensShield tile backer, or other suitable substrate.

2. Waterproof the Walls

• Apply waterproofing membrane like RedGard over entire surface and seams.
• Or use a vapor-barrier paint primer for moisture protection.

3. Plan Your Layout

• Map stud locations for securing panels.
• Measure and calculate panels needed based on room size.
• Sketch panel layout for optimal arrangement and appearance.

4. Prime and Paint

• Fill any gouges or imperfections with spackle; sand smooth.
• Prime walls and back-sides of panels with quality primer.
• Paint walls and panels with bathroom enamel paint.

5. Install the Shiplap

• Start in a corner and work outward in rows.
• Use finish nails or screws to hit studs or masonry anchors.
• Leave 1/4" gaps between panel edges.
• Use painter‘s tape along ceilings/floors for clean edges.

6. Seal the Shiplap

• Caulk all seams and gaps with flexible silicone caulk.
• Apply final waterproof coating like RedGard over panels.
• Seal around fixtures, outlets, pipes, etc.

7. Finish Details

• Install trim, baseboards, fixtures.
• Caulk along countertops, tub, and high humidity areas.
• Consider adding tile backsplashes.

Installing shiplap well takes precision – but the results are worth it. Be sure to inspect periodically for any moisture issues. Address them promptly to prevent costly damage.

Caulking Tips for Waterproof PVC Shiplap

Proper caulking deserves special mention, as it‘s crucial for waterproofing. Here are my top professional tips:

• Always use flexible silicone caulk in bathrooms – it withstands movement and wetness.

• Only apply caulk to clean, dry surfaces – use denatured alcohol to prep.

• Cut nozzle at 45° angle to around 1/8" – this allows smooth caulk flow.

• Apply caulk in continuous straight beads without gaps or stops.

• Smooth the beads with a putty knife or finger dipped in water. Blend and flatten.

• Make sure caulk fully fills gaps and makes contact with both sides.

• Allow caulk to cure fully (typically 24-48 hours) before exposure to water.

• Reapply fresh caulk every 1-2 years to maintain waterproof seals.

Maintenance Tips for PVC Shiplap in Bathrooms

To keep your bathroom PVC shiplap looking beautiful, make sure to:

• Use a mild cleaner and soft cloth. Avoid harsh chemicals or scrubbing.

• Re-caulk seams every 1-2 years to maintain waterproof seals.

• Repaint periodically with bathroom enamel paint for added moisture protection.

• Inspect for moisture issues like bubbling, peeling, discoloration, or mold. Address immediately.

• Avoid direct water contact as much as possible by using shower curtains and wiping up spills promptly.

• Consider resealing with waterproofing finish every 3-5 years for optimal longevity.

With proper installation and routine care, PVC shiplap can last for many years in bathroom environments. But issues can occur if moisture seals fail. Inspect regularly and address promptly.

Creative Uses of PVC Shiplap in Showers

While direct water contact should be avoided, PVC shiplap can be incorporated creatively into shower surrounds with a few precautions:

• As an accent wall opposite the showerhead to limit water exposure.

• On the ceiling only to add visual intrigue overhead.

• Behind a shower niche or recessed shelves where water contact is contained.

• As wainscoting along lower walls below tile or a tub/shower surround.

• On the exterior of curbless showers since water stays contained inside.

• Behind backsplashes or benches that limit direct water flow.

Whenever installing PVC shiplap in shower surrounds, take safety precautions and consult a professional to ensure proper waterproofing for your specific application. Limiting direct water contact is key.

Bathroom Wall Alternatives to PVC Shiplap

While PVC shiplap has many favorable attributes for bathrooms, it’s not the only option. Here are a few popular alternatives:

• Tile or stone – Beautiful and impervious to water but requires professional installation. High maintenance grout.

• Fiberglass reinforced plastic (FRP) panels – Budget-friendly, waterproof, and easy to install and clean. Industrial aesthetic.

• Beadboard – Timeless look when made of moisture-resistant woods like cedar or redwood. Must be properly sealed.

• Moisture-resistant drywall – With mold-inhibiting additives and proper finishing, performs well in wet areas.

• Solid surface acrylic – Expensive but provides a seamless, custom colored and completely waterproof finish.

• Glass tile – Gorgeous option when professionally installed. Very expensive.

Conclusion

I hope this guide has helped explain what to know when considering PVC shiplap in bathroom installations. While not inherently waterproof, it can be properly prepped and sealed to withstand moisture and humidity. Focus on caulking seams, allowing ventilation, limiting direct water contact, and using bathroom-friendly finishes. When installed correctly, PVC shiplap can offer a budget-friendly and stylish bathoom look. But alternative options may be better suited for certain applications. As always, don‘t hesitate to contact a home improvement professional like myself for project-specific advice.