Understanding Shiplap and Its Applications
Shiplap is a type of wooden or composite panel featuring interlocking rabbeted edges that create overlapped joints. Originally used for exterior weatherproofing, it has become a popular interior design choice for walls and ceilings across modern, farmhouse, industrial, and traditional styles.
- Wood varieties include hardwood, cedar, and pine, offering durability and natural grain character.
- Composite options like PVC and MDF provide moisture resistance and lower cost alternatives.
- Standard widths are 5¼ and 7¼ inches, though lengths and thicknesses vary by manufacturer.
- Installation orientation can be horizontal (widening effect), vertical (heightening effect), or diagonal (decorative pattern).
Board prices range from £1–£11 per square foot depending on material: PVC boards cost £1–£5/sq ft, plywood £2–£3/sq ft, while hardwood reaches £2–£11/sq ft before installation labour.
Shiplap Board Quantity Formula
To find how many boards you need, calculate your project area first, then divide by the coverage area of a single board. If your space has windows or doors, subtract their dimensions from the total wall area.
For a simple flat wall or ceiling:
Project Area = Length × Height
Boards per Sq Ft = 144 ÷ (Board Length × Board Width)
Number of Boards = Boards per Sq Ft × Project Area
For walls with windows and/or doors:
Project Area = (Length × Height) − (Window Area + Door Area)
Number of Boards = Boards per Sq Ft × Project Area
Total project cost with wastage:
Total Cost = (Number of Boards × Board Price) + (Project Area × Installation Rate)
Project Area— Total square footage to be covered, accounting for wall height and length minus openingsBoard Length & Width— Dimensions of a single shiplap board in inchesBoards per Sq Ft— Number of boards required to cover one square foot, calculated as 144 divided by board area in square inchesWastage Factor— Percentage of extra boards to account for breakage and cutting waste, typically 5–10%Installation Rate— Labour cost per square foot, usually £0.75–£3 depending on region and complexity
Step-by-Step Installation and Preparation
Before ordering materials, prepare your surface and plan your layout carefully. Proper preparation ensures a professional finish and reduces waste.
- Surface preparation is critical: clean the wall or ceiling thoroughly, remove dust, and ensure it is level. Check for moisture; damp surfaces encourage mold growth and board warping.
- Frame with cleats perpendicular to your shiplap direction. For horizontal boards, run cleats vertically at 16-inch intervals. For vertical boards, space horizontal cleats 24 inches apart.
- PVC paneling is simpler—glue it directly to a clean, dry wall using construction adhesive. No framing is needed.
- Wood shiplap requires fastening with nails or screws through the cleats into studs. Pilot holes prevent splitting, especially in harder woods like cedar.
- Account for layout by starting at the bottom and working up for horizontal installations, or beginning at one corner for vertical work. Plan your cuts so seams are hidden or symmetrical.
Common Pitfalls and Practical Considerations
Avoid these mistakes that add time, cost, or compromise the finished look.
- Ignoring moisture and humidity — Shiplap expands and contracts with moisture changes. Install vapour barriers behind the boards if your room is humid or prone to temperature swings. Acclimate wood boards to your home's environment for 48 hours before installation.
- Underestimating wastage and cuts — Budget 8–10% extra boards for cuts around windows, doors, and corners. Diagonal or herringbone patterns generate more waste than simple horizontal layouts. Always round up your board count to the nearest whole number.
- Choosing boards by price alone — Cheaper plywood or MDF may warp, shrink, or show seams over time. Pine and cedar hold up better for visible interior walls. Investment in quality wood returns better aesthetics and longevity.
- Miscalculating area with openings — Subtract window and door areas at full dimensions; do not assume partial coverage. An 8 ft × 3 ft window is 24 square feet to exclude, which can reduce board count significantly. Measure twice before ordering.
Material Types and Cost Expectations
Your material choice affects both initial cost and long-term performance. Each type has distinct advantages for different applications.
- Hardwood boards (£2–£11/sq ft) offer superior durability and rich grain patterns but require skilled finishing and careful installation.
- Cedar (£2–£8/sq ft) is naturally rot-resistant and aromatic, ideal for high-moisture areas or accent walls.
- Pine (£2–£7/sq ft) is affordable, lightweight, and paintable, making it popular for farmhouse and cottage styles.
- Plywood (£2–£3/sq ft) is budget-friendly and stable but shows visible layers at edges and seams.
- MDF (£2–£10/sq ft) mimics solid wood, accepts paint well, and is ideal for primed finishes.
- PVC panels (£1–£5/sq ft) resist moisture and mold, requiring no framing—excellent for bathrooms and kitchens.
Installation labour ranges from £0.75–£3 per square foot. Simple horizontal layouts on flat walls cost less than complex geometric patterns or diagonal installations. Total project expenses typically run £3–£14 per square foot all-in.