How Do I Figure Out How Much Shiplap I Need?

Shiplap has become one of the most popular wall treatments for creating character and texture in any room. Whether you're planning an accent wall, covering an entire room, or adding rustic charm to your ceiling, accurately calculating how much shiplap you need is the crucial first step to a successful project. At TexasVJoint, we want to ensure you order the right amount of material the first time, saving you time, money, and frustration.

This comprehensive guide will walk you through the entire calculation process, from basic measurements to accounting for waste and special considerations. Browse our Shiplap & Nickel Gap collection as you plan your project to see the beautiful options available.

Understanding Shiplap Basics

Before diving into calculations, it's important to understand what you're working with. Shiplap boards have a rabbet (notch) cut along the top and bottom edges that allows them to overlap, creating that signature tight, clean look with a small shadow line between boards.

Coverage vs. Actual Width: This is the most important concept for accurate calculations. A shiplap board might be 6 inches wide, but once installed with its overlap, it only covers about 5.5 inches of wall space. Always calculate based on coverage width, not actual board width.

The Basic Calculation Formula

Calculating shiplap needs involves a straightforward process:

Step 1: Measure Your Space

Start by measuring the area you want to cover. For walls, measure the width and height in feet. For more complex spaces, break them down into rectangles and measure each section separately.

Single Wall Example: If your wall is 12 feet wide and 8 feet tall, your square footage is 96 square feet (12 × 8 = 96).

Multiple Walls: Measure each wall separately, then add the square footage together. A room with walls measuring 96 sq ft, 80 sq ft, 96 sq ft, and 80 sq ft would total 352 square feet.

Step 2: Subtract Openings

Don't pay for material you won't use. Subtract the area of windows, doors, and other openings from your total square footage.

Standard Door: Approximately 21 square feet (3 feet × 7 feet) Standard Window: Varies, but a typical window might be 15 square feet (3 feet × 5 feet)

Using our earlier example, if you have two windows (30 sq ft) and one door (21 sq ft), subtract 51 square feet from 352, leaving you with 301 square feet of actual coverage needed.

Step 3: Add Waste Factor

Here's where many DIYers underestimate their needs. You'll always have waste from:

• Cut ends and mistakes
• Damaged or defective boards
• Cutting around obstacles
• Matching patterns or choosing the best-looking boards

Recommended Waste Factors:

• Simple, rectangular walls: Add 10%
• Walls with multiple windows/doors: Add 15%
• Angled ceilings or complex layouts: Add 20%
• First-time installers: Add an extra 5%

For our 301 square feet example with a standard layout, multiply by 1.15 (adding 15%): 301 × 1.15 = 346 square feet needed.

Step 4: Account for Board Coverage

Remember that coverage width principle? You need to know how many square feet one board actually covers. This information should be available from your supplier.

Example Calculation:

• Board actual width: 6 inches
• Board coverage width: 5.5 inches
• Board length: 8 feet
• Coverage per board: (5.5 inches ÷ 12) × 8 feet = 3.67 square feet per board

Divide your total square footage by coverage per board: 346 ÷ 3.67 = 94.3, so you'd need 95 boards.

Quick Reference Chart

Here's a simplified chart for common shiplap installations (assumes 15% waste factor):

Special Considerations for Different Installations

Horizontal vs. Vertical Installation

Horizontal Installation (most common): Boards run parallel to the floor. This is the traditional approach and typically requires less waste because you're working with the full length of boards.

Vertical Installation: Boards run from floor to ceiling. This creates a modern look and can make rooms appear taller. Vertical installations often require more waste allowance (add an extra 5%) because you might need to cut multiple boards to achieve the ceiling height.

Ceiling Applications

Installing shiplap on ceilings follows the same calculation process, but consider these factors:

• Ceiling work is more physically demanding, so factor in potentially more mistakes
• Add 20% waste factor for ceiling projects
• Consider how ceiling fixtures, vents, and lights will affect your layout
• Account for the direction of your boards (parallel or perpendicular to joists)

If you're also considering ceiling treatments, explore our V-Groove collection for beautiful alternatives that work wonderfully overhead.

Accent Walls

Accent walls are a popular way to add shiplap without committing to an entire room. The calculation is simpler but still important:

• Measure your wall dimensions carefully
• Subtract any openings (windows, doors, wall-mounted TVs)
• Add 10-15% waste
• Consider buying a few extra boards for future repairs

Diagonal or Herringbone Patterns

Planning something more adventurous? Diagonal and herringbone patterns create stunning visual interest but require significantly more material:

• Add 25-30% waste factor
• Plan your pattern on paper first
• Consider purchasing extra boards for the learning curve
• Each angled cut creates waste from both pieces

Tips for Accurate Measuring

Use the Right Tools

Invest in quality measuring tools:

• 25-foot tape measure (minimum)
• Laser distance measurer for large or high spaces
• Level to ensure straight reference lines
• Notepad or smartphone app to record measurements

Measure Multiple Times

The old carpenter's adage holds true: measure twice, cut once. For shiplap calculations, measure each wall in at least two places (height and width) to account for settling or construction irregularities.

Account for Irregular Walls

Not all walls are perfectly rectangular. For walls with:

• Sloped ceilings: Measure at the highest and lowest points, calculate the average height
• Bay windows or alcoves: Break into separate rectangular sections
• Bump-outs or recesses: Measure each section independently

Don't Forget Trim

Shiplap installations typically require trim pieces to finish the look:

• Baseboard: Covers the bottom edge and protects from damage
• Crown Moulding: Finishes the top edge with elegance
• Trim & Cove Moulding: Frames corners and openings

Measure the perimeter of your installation area (in linear feet) to determine trim needs. Add 10% for waste on trim as well.

Common Calculation Mistakes to Avoid

Mistake #1: Using Actual Width Instead of Coverage Width

This is the number one error. If you calculate based on the 6-inch actual width instead of the 5.5-inch coverage width, you'll come up short by about 10%.

Mistake #2: Forgetting the Waste Factor

Even experienced installers have waste. Skipping the waste calculation almost guarantees you'll run short and need to make an additional order, which can delay your project and may result in slight color variations between batches.

Mistake #3: Not Accounting for Board Length Options

Shiplap comes in various lengths (typically 6, 8, 10, or 12 feet). Longer boards mean fewer seams and less waste, but they may not fit in your vehicle or be practical for your space. Consider:

• Your vehicle's capacity
• Maneuverability in your workspace
• Whether continuous runs are possible or if seams are necessary

Mistake #4: Ignoring Direction and Layout

The direction you install shiplap affects material needs. Running boards lengthwise across a narrow wall wastes less material than running them across a wide wall where you'll have many short leftover pieces.

Real-World Example: Complete Bedroom Calculation

Let's walk through a complete example for a bedroom shiplap accent wall:

Room Details:

• Accent wall: 14 feet wide × 8 feet tall = 112 sq ft
• One window: 4 feet × 3 feet = 12 sq ft
• Horizontal installation
• Using 6-inch actual width shiplap (5.5-inch coverage)
• Boards available in 8-foot lengths

Calculation:

1. Total wall area: 112 sq ft
2. Subtract window: 112 - 12 = 100 sq ft
3. Add 15% waste: 100 × 1.15 = 115 sq ft
4. Coverage per board: (5.5 ÷ 12) × 8 = 3.67 sq ft per board
5. Boards needed: 115 ÷ 3.67 = 31.3 boards
6. Order 32 boards

Additional Materials:

• Baseboard: 14 feet × 1.10 = 16 linear feet
• Top trim: 14 feet × 1.10 = 16 linear feet
• Corner trim (if applicable): 8 feet × 2 sides = 16 feet

Ordering From TexasVJoint

At TexasVJoint, we make the ordering process simple. Our Shiplap & Nickel Gap collection provides clear specifications for each product, including:

• Actual board dimensions
• Coverage dimensions
• Available lengths
• Square footage per piece or bundle

Many of our products are sold by the piece, giving you precise control over your order. If you're between quantities, we always recommend ordering up rather than short. Extra boards can be used for future repairs or other small projects around your home.

Can't Decide Between Styles?

While shiplap is incredibly popular, we also offer other wall treatment options that might suit your project:

• Beadboard: Provides more texture with vertical grooves, perfect for cottage and coastal styles
• V-Groove: Creates crisp, clean lines with a modern aesthetic
• Tongue & Groove: Offers a tight, seamless look without the shadow line

Each style has different coverage calculations, so use the same basic formula but adjust for the specific coverage width of your chosen product.

Using Online Calculators

While manual calculations work perfectly well, many suppliers (including TexasVJoint) offer online calculators to simplify the process. These tools typically ask for:

• Room dimensions (length, width, height)
• Number and size of openings
• Installation direction (horizontal/vertical)
• Product selection

The calculator will automatically account for coverage width and add appropriate waste factors. However, understanding the manual calculation process helps you verify results and make informed decisions.

What to Do With Leftover Shiplap

Even with perfect calculations, you'll likely have some leftover material. Don't let it go to waste:

• Keep for repairs: Store a few boards for future repairs or when you need to access walls for electrical or plumbing work
• Small projects: Use leftovers for smaller DIY projects like picture frames, headboards, or closet accent walls
• Samples: Keep pieces as samples when planning future projects or coordinating paint colors

Pro Tips for Reducing Waste

While you should always include a waste factor, these strategies help minimize unnecessary waste:

1. Plan your layout before cutting: Map out where each board will go, especially around openings
2. Cut strategically: Use the offcut from one board as the starter for another row
3. Start with longer boards: Use your longest boards for uninterrupted runs, saving shorter pieces for areas with windows and doors
4. Stagger your seams: In longer runs requiring multiple boards, stagger seams for a more professional look and to use cutoffs efficiently
5. Save cutoffs: Even short pieces can be useful for filling in around outlets, switches, or above/below windows

To Summarize

Calculating shiplap needs doesn't have to be intimidating. By following these steps—measuring accurately, subtracting openings, adding an appropriate waste factor, and understanding coverage versus actual width—you'll order the right amount of material for your project.

Remember, it's always better to have slightly too much than to run short mid-project. Color and grain can vary between batches, and project delays waiting for additional material are frustrating.

At TexasVJoint, we're committed to helping you succeed with your shiplap project from start to finish. Our high-quality materials, clear specifications, and helpful customer service ensure you get exactly what you need. Whether you're covering a small accent wall or transforming an entire room, accurate calculations are your foundation for success.

Ready to start your shiplap project? Explore our full Shiplap & Nickel Gap collection and use these calculation guidelines to determine exactly how much you need. Happy installing from the TexasVJoint team!