Nailing shiplap siding correctly takes more than driving nails through overlapping boards. The right method depends on the siding material, profile, exposure, and manufacturer’s instructions. For exterior work, sound fastening must also work with the home’s water-resistive barrier, flashing, and drainage plane. This guide explains how to plan the job, choose fasteners, position each board, and avoid common problems—while noting where product-specific directions take priority.
What Makes Shiplap Siding Different?
Shiplap boards have opposing rabbeted edges that overlap when installed. The overlap helps create a consistent appearance and sheds water, but it does not make the wall waterproof. Wind-driven rain can enter joints, and moisture can collect behind siding if the wall lacks proper drainage and flashing.
Shiplap is a profile, not a single material. Exterior products may be wood, engineered wood, fiber cement, or another composite. Their thickness, edge details, nail zones, and fastening requirements differ. Interior shiplap boards are not automatically suitable for exterior exposure; confirm that the product is rated for the intended use.
Start with the product’s current installation instructions. They determine the permitted fastener type and size, nail placement, board spacing, substrate, and any required sealants. If those directions conflict with general advice, follow the manufacturer and applicable local requirements.
Plan the Wall Before Nailing
Check the existing structure and siding system
Confirm that the wall framing or approved sheathing can support the siding and that the substrate is sound, flat, and dry. Repair rot, loose sheathing, and water damage before covering the wall. If removing old siding, investigate any suspected hazardous materials before disturbing them; older coatings and building products may require professional assessment.
Exterior siding is part of a wall assembly. A water-resistive barrier (WRB), properly integrated flashing, and suitable drainage details help protect the structure behind it. The siding’s overlapping joints are not a substitute for these layers. Follow the siding maker’s requirements for installing over sheathing, furring, or a rainscreen cavity, and check local building code.
Measure and establish a level reference
Measure the wall and calculate how many boards are needed, allowing for cuts and waste. Establish the first course with a level or laser; small errors at the bottom can become conspicuous as the courses climb. At corners and openings, plan board ends so they land where the required support and fastening can be provided.
Mark stud locations on the WRB or temporary reference strips when the fastening plan calls for attachment to framing. Check the wall for plumbing, wiring, and other concealed services before driving long nails. A stud finder, plans, and careful verification can reduce the risk of damage.
Choose the Right Nails and Tools
Fasteners should be approved for the siding material and exposure. Exterior siding generally calls for corrosion-resistant nails, such as the type specified by the manufacturer; the appropriate coating or metal can depend on the siding, climate, and nearby materials. In coastal or highly corrosive environments, requirements may be more demanding. Do not assume ordinary interior finish nails are suitable outdoors.
Nail length must account for the siding thickness and the required embedment into the supporting framing or other approved substrate. There is no one nail length or spacing rule for every shiplap product. Check the product’s fastening schedule, including whether nails must hit studs, what nail shank and head are required, and whether the profile allows concealed fastening.
Useful tools may include a tape measure, level, chalk line, saw appropriate to the product, drill or nailer approved for the fastener, hammer, and eye and hearing protection. Use the specified nailer pressure and settings. For fiber cement or other products that produce hazardous dust when cut, follow the manufacturer’s cutting guidance and use appropriate dust controls and respiratory protection.
How to Nail Shiplap Siding
- Prepare the wall. Install the WRB, flashing, and any furring or drainage components required for the assembly. Lap and integrate these materials in the prescribed sequence so water is directed outward and down. Keep openings, wall bases, and roof intersections consistent with the siding and flashing instructions.
- Set the starter course. Install the specified starter strip or first-board detail. Use a level to position the course, and leave required clearances at the foundation, rooflines, and other surfaces. Do not bury siding in soil or bridge a required drainage gap.
- Fit the first board. Cut the board cleanly and dry-fit it. Follow the instructions for end joints, including required support, joint staggering, and spacing. Apply sealant to cut ends only if the product instructions require it; some systems specify particular coatings or joint treatments.
- Fasten according to the profile. Place nails in the approved fastening zone. Some shiplap profiles are designed for face nailing; others may permit concealed fastening through a designated overlap. Do not choose a hidden-nail method simply for appearance if the manufacturer requires face nails or a different pattern.
- Drive nails correctly. Keep the nail straight and drive it flush or to the specified depth. A protruding head can interfere with the next course, while overdriving can crush the board, damage a face layer, or reduce holding strength. Avoid placing nails too close to board ends or edges unless the instructions specify otherwise.
- Install the next course. Engage the rabbeted edges without forcing them together. Preserve the required joint or expansion allowance for the material and climate. Check each course for level and consistent exposure before fastening; do not rely on the overlap to correct a crooked board.
- Continue around openings and corners. Maintain the specified clearances and flashing details at windows, doors, trim, and penetrations. Cut and fit pieces so water can drain as intended. Never cover flashing weep paths or drainage openings with trim or sealant.
- Inspect as work progresses. Confirm that nails are in the correct zones, boards lie flat, joints are supported as required, and the courses remain level. Correct errors before they are hidden by later boards.
Face Nailing Versus Concealed Nailing
Face nailing means the nail passes through the visible face of the board. It is common for siding profiles that require direct fastening through the board into framing or an approved substrate. The visible heads should be aligned consistently and finished as directed. On some products, exposed nail heads are part of the intended installation.
Concealed nailing places the fastener in a covered portion of the profile so the next board hides it. It can produce a cleaner appearance, but it is suitable only when the product is designed and tested for that method. A nail driven through a thin lip or an unauthorized location may split the edge or fail to secure the board properly.
Shiplap’s overlap does not, by itself, determine which approach is correct. Read the fastening diagram for the exact board profile. If the instructions are unclear, contact the manufacturer before installation rather than improvising a pattern.
Fastening Details That Prevent Damage
Avoid overdriving and splitting
Overdriven nails can compress wood fibers, fracture engineered products, or damage a coating. Underdriven nails can hold the next course away from the wall or prevent proper overlap. Set a nailer carefully on scrap of the same material, then inspect the result before working on the wall.
Pre-drilling may be required near ends, for certain dense materials, or when the instructions call for it. Use the specified drill-bit size and technique. Do not countersink or fill fastener heads unless the product’s finishing instructions permit it.
Allow for movement and drainage
Wood and many manufactured siding products change dimension with moisture or temperature. The manufacturer’s specified gap, overlap, and clearance details help accommodate movement. Caulking every joint is not a universal solution: some joints are intended to drain, and unnecessary sealant can trap water or interfere with the system.
At butt joints and trim intersections, use the prescribed flashing or joint detail. Sealant should be used only where specified, with compatible materials and appropriate joint preparation. Keep the lower edge and other drainage paths unobstructed.
Common Mistakes to Avoid
- Using the wrong product: Interior-only shiplap may swell, deteriorate, or fail outdoors.
- Choosing nails by habit: Incorrect material, length, shank, or head can cause corrosion or inadequate holding.
- Ignoring the fastening schedule: Nail location and spacing vary by product and wall assembly.
- Skipping the WRB and flashing: Overlapping boards do not replace water-management layers.
- Forcing boards tightly together: This can restrict movement or distort the profile when the product requires a gap.
- Overdriving nails: Excessive depth can weaken the board or damage its surface.
- Blocking drainage: Excess sealant or misplaced trim can trap water behind the siding.
- Starting out of level: A crooked first course makes later courses harder to align.
Wood, Engineered Wood, and Fiber Cement Considerations
For solid wood shiplap, moisture content, species, board width, and exposure affect movement and fastening. Store boards flat and protected, and follow the product’s guidance for acclimation, priming, end treatment, and finish. Paint or stain does not eliminate the need for proper flashing and drainage.
Engineered wood products may have specific requirements for nail type, spacing, edge distance, joint treatment, and clearance from grade or roofs. Their factory coatings and cut-edge treatments also vary. Use the exact instructions for the brand and profile rather than applying a schedule from a different product.
Fiber-cement siding requires particular attention to product-specific fastening zones and cutting practices. Its boards may be brittle at edges, and cutting can create respirable dust. Follow the manufacturer’s safety and installation directions, including approved tools, dust controls, and any required clearances.
When to Call a Professional
A qualified siding contractor can help when the wall has extensive rot, unusual framing, complex roof-to-wall intersections, or uncertain drainage details. Professional help is also prudent when the siding material is unfamiliar, a required fastening schedule is unavailable, or local code and manufacturer instructions are difficult to reconcile.
For a straightforward installation, the most reliable rule is simple: identify the exact siding product, use its current fastening diagram, and treat water management as part of the job—not as a detail to address after the boards are nailed. The U.S. Department of Energy’s air-sealing guidance and local building department resources can help explain related wall-performance considerations, while the siding manufacturer remains the primary source for product-specific installation instructions.