# Making Shiplap Waterproof: The Expert Guide - Canonical: https://33rdsquare.com/making-shiplap-waterproof-the-expert-guide/ - Published: 2023-10-09 - Author: Lillie Gabler - Categories: [Tips](https://33rdsquare.com/category/home/tips/) --- As a home renovation specialist with over 10 years of experience, I‘m often asked if it‘s possible to use shiplap in high moisture areas like bathrooms, kitchens, and outdoor spaces. The short answer is yes – with the right preparation, you can absolutely make shiplap waterproof and suitable for any area of your home. In this comprehensive guide, I‘ll share my proven expertise on effectively waterproofing shiplap using the right materials, installation methods, and maintenance practices. Read on to learn insider tips that will allow you to confidently install beautiful, lasting shiplap anywhere. ## An Introduction to Shiplap For those unfamiliar, **shiplap refers to wooden boards designed with rabbeted edges that allow them to fit snugly together**. The lip of one board overlaps the next, creating tight seams and a flush surface. It provides a charming rustic look popular for walls, ceilings, and accent features. ### The Problem With Moisture While stunning, untreated shiplap can become damaged when exposed to excessive moisture over time. Water can cause the boards to swell, warp, crack, or even rot away completely. This vulnerability to dampness might make you hesitant to use shiplap in humid environments like bathrooms. However, it is possible to **create a water-resistant barrier** so shiplap can be installed anywhere. In this guide, I‘ll share the professional techniques I‘ve learned for preparing, installing, and maintaining shiplap to withstand moisture in any space. ## Choosing the Best Water-Resistant Wood The specific type of wood you select plays a major role in natural water resistance. Although all woods require waterproofing, some varieties are more prone to moisture damage. Based on my renovation experience, here are the best woods for waterproof shiplap: ### Cedar - Naturally resistant to water and insects due to high oil content - Resists rotting and decay - Stains well for an attractive finish - Cedar shiplap siding can last over 15 years ### Redwood - Very dense grain repels water efficiently - Redwood shiplap siding can last 20+ years with proper maintenance - Takes beautiful stains and finishes ### Teak - One of the most water-resistant woods due to high oil content - Often used for boat decking due to durability - Can last over 25 years outdoors ### White Oak - Dense grain and tannins make it resistant to rotting and insects - Can last over 20 years with upkeep - Does well with stains and finishes **I recommend avoiding very softwoods like pine** that absorb moisture readily. The most suitable shiplap woods have a dense grain and naturally repel dampness. While no wood is 100% waterproof, starting with an oil-rich, rot-resistant species provides an excellent foundation. ### Pressure Treated Wood Lumber labeled "pressure treated" has been immersed in preservatives that helps protect against rot and decay. Pressure treated boards are ideal for shiplap in frequent wet conditions like outdoor installations. ## Waterproofing Shiplap Before Installation For best results, I advise treating shiplap boards _before_ installation while you have full access to all sides. Here is the process I follow: ### Step 1: Sand and Clean Lightly sanding prepares the surface for maximum finish adhesion. Wipe each board with a clean rag to remove any debris. ### Step 2: Apply Exterior Wood Sealant Using a sprayer or brush, apply a penetrating sealer formulated for outdoor wood: - Fully coat all surfaces of boards – edges and ends are most vulnerable. - Allow to dry completely per manufacturer instructions before adding more coats. - 2-3 coats ensures robust moisture protection. ### Step 3: Add Exterior Paint or Stain For extra waterproofing and beauty, apply exterior grade paint or stain over the sealant: - Oil-based tends to resist moisture better than latex. - Thoroughly treat all sides and edges just as you did with the sealant. - Let dry 72+ hours before installation. This comprehensive pre-treatment allows the shiplap to withstand exposure once mounted. ## Waterproofing After Installation Pre-finishing is ideal, but shiplap can still be effectively treated after mounting by: - Carefully applying sealants and paints/stains only to visible surfaces - Filling any gaps with exterior caulk - Ensuring adequate airflow circulation behind boards - Adding trim caps along seams for added protection With proper prep, even installed shiplap can be waterproofed successfully. ## Maintenance Practices To make your waterproofing last, I recommend: ### Reapply Sealants - Low exposure: Every 2-3 years - Moderate exposure: Annually - High exposure: Every 6-12 months Check for worn spots and recoat compromised areas promptly. ### Inspect Frequently Look for any swelling, cupping, cracking, or finish breakdown. Immediately repair any vulnerabilities to prevent moisture intrusion. ### Avoid Direct Water Contact Keep splashing, condensation, and direct moisture contact away from shiplap. Quickly dry any sitting water to prevent absorption. With vigilant maintenance, your shiplap can maintain its protective barrier against moisture damage. ## FAQs About Waterproof Shiplap Here are answers to some common questions I receive about waterproofing shiplap based on my renovation knowledge: ### What sealant is best for shiplap? I recommend a clear water-repellent exterior wood sealant. Look for advanced “waterproofing” formulas designed for minimizing moisture absorption. ### Can shiplap warp from water damage? Absolutely. If left unprotected, excessive moisture exposure can cause shiplap boards to swell, split, crack, cup, and rot away. Properly sealing and maintaining it reduces this risk. ### How do I waterproof bathroom shiplap? Pre-treat boards as outlined above. During install, apply a waterproof membrane behind boards and use mold-resistant caulk at all seams. Ensure adequate ventilation behind shiplap. ### Can shiplap go outside? Yes, with proper preparation – use marine grade sealants, pressure treated lumber, or naturally water-resistant woods. Providing a roof overhang helps minimize direct water exposure. Let me know if you have any other shiplap waterproofing questions! I‘m always happy to share my professional experience. Regards, Lillie Home Renovation Specialist --- Source: [Making Shiplap Waterproof: The Expert Guide](https://33rdsquare.com/making-shiplap-waterproof-the-expert-guide/)