How to Replace Cedar Siding: A Step-by-Step Guide

Cedar siding can last for decades, but damaged boards, persistent moisture, and failing paint can eventually make replacement necessary. A successful project involves more than attaching new boards: the wall’s water-resistive barrier, flashing, ventilation, and trim all need attention. This guide explains how to evaluate existing siding, plan a replacement, choose materials, and install cedar siding with durability and safety in mind. Local building codes and the siding manufacturer’s instructions should guide the work, since requirements and installation details can vary by home and product.

Decide Whether Cedar Siding Needs Replacement

Not every worn board calls for a full siding replacement. Cedar is a natural material, and isolated damage can often be addressed by replacing individual boards or improving the paint and maintenance routine. A broader project may make sense when deterioration is widespread or when removing the siding is necessary to correct problems behind it.

Inspect for soft or crumbling wood, deep splits, loose boards, recurring peeling paint, and visible decay. Pay particular attention to lower wall sections, corners, window and door openings, and areas near gutters, rooflines, decks, and plumbing penetrations. These locations are more likely to receive water or remain damp.

Look for causes as well as symptoms. Poor drainage, leaking gutters, missing flashing, soil or mulch piled against siding, and inadequate clearance from roofs or hard surfaces can shorten the life of new cedar. If a wall feels soft, has persistent stains, or shows signs of water entering indoors, investigate before covering or replacing the boards.

• Consider spot repairs when damage is limited to a few boards and surrounding siding is sound.
• Consider replacing a wall or larger area when many boards are split, decayed, or no longer securely attached.
• Arrange a professional assessment if the wall has extensive water damage, structural concerns, or complicated historic details.

Plan the Project and Check Local Requirements

Before ordering materials, identify the existing siding profile and measure each wall. Common cedar siding styles include bevel (also called clapboard), shiplap, tongue-and-groove, and shingles. The replacement should match the existing profile, thickness, and exposure—the visible portion of each course—if the goal is a consistent appearance. Bring a sample board to a lumberyard or siding supplier when matching older siding.

Measure the wall area and add a reasonable allowance for cuts, defects, and future repairs. The exact amount depends on the layout and product. Openings such as windows and doors reduce the surface area, but cutting waste can offset some of that reduction. Ask the supplier to confirm coverage per board or bundle rather than relying only on nominal board dimensions.

Check local building department requirements before work begins. Permits, required water-resistive barriers, flashing details, and rules for exterior changes vary by location and project. Homes in wildfire-prone areas may also have specific exterior material and clearance requirements. Where the home is subject to a homeowners association or historic district review, approval may be needed before changing the siding profile or finish.

For homes built before 1978, paint may contain lead. The U.S. Environmental Protection Agency (EPA) requires certified firms performing covered renovation, repair, and painting work in most pre-1978 housing to follow the Renovation, Repair and Painting (RRP) Rule. Lead-safe practices include containing dust and debris, using appropriate work methods, and cleaning the area. Homeowners should check EPA guidance and state or local rules before disturbing old painted siding. Do not dry-sand or power-sand paint that may contain lead.

Choose Cedar Siding and Fasteners

Cedar species, grades, dimensions, and drying conditions affect appearance and performance. Western red cedar is widely used for exterior siding, but availability differs by region. Select siding rated and intended for exterior use, and follow the supplier’s instructions for installation and finishing. Boards should be stored flat, protected from rain and ground moisture, and allowed to acclimate as directed by the manufacturer.

Preprimed or factory-finished siding can reduce on-site coating work, but cut ends and field-cut areas may still need treatment. When finishing on site, use a coating approved for cedar and exterior siding. Paint, solid-color stain, and semitransparent stain have different appearances and maintenance needs. A paint or coating manufacturer can specify compatible primers and application conditions.

Fasteners must be suitable for exterior exposure and compatible with the cedar and any metal flashing. Corrosion-resistant nails—commonly stainless steel or hot-dipped galvanized, as appropriate—help reduce staining and premature failure. The correct nail type, length, and placement depend on siding thickness, wall assembly, and product instructions. Avoid assuming that one fastener schedule applies to every profile.

Tools and Materials

Typical work may require a tape measure, level, chalk line, circular saw, utility knife, pry bar, hammer or siding nailer, and a ladder or properly set up scaffold. Safety glasses, hearing protection, gloves, and a suitable respirator are also important, especially when cutting or removing old materials. Use tools according to their manuals and keep bystanders away from cutting and demolition areas.

Materials commonly include replacement cedar boards, corrosion-resistant fasteners, compatible flashing, a water-resistive barrier or repair materials, exterior sealant where the design calls for it, and primer or finish. The wall may also need replacement trim, starter strips, or insect-screening components. Sealant is not a substitute for correctly installed flashing or a drainage plane.

Remove Existing Siding Carefully

Start by moving outdoor furniture and protecting plants, windows, and nearby surfaces. Set up ladders or scaffolding on stable ground and avoid working in high winds, rain, or other unsafe conditions. Remove trim or siding in a controlled sequence so boards and debris do not fall onto people or property.

Use a thin pry bar to release nails and lift boards without damaging the sheathing more than necessary. Work carefully around windows, doors, electrical fixtures, and utility lines. If the siding is painted and the home predates 1978, follow applicable lead-safe requirements. Stop if demolition reveals a material that may be hazardous or cannot be identified; qualified testing or a licensed professional may be appropriate.

As each section comes off, inspect the sheathing, framing, and existing water-resistive barrier. Look for rot, mold, insect damage, damp insulation, and staining. Do not install new siding over damaged or wet materials. Determine the source of any moisture and repair it first. Significant structural deterioration may require a qualified contractor.

Repair the Wall and Manage Water

A durable siding installation depends on the layers behind the boards. Repair damaged sheathing and framing with materials and methods appropriate to the wall assembly. Replace or repair the water-resistive barrier so it forms a continuous drainage plane. Follow the barrier manufacturer’s instructions for seams, transitions, and integration with flashing.

Install or correct flashing at windows, doors, roof-to-wall intersections, decks, and other places where water can enter. Flashing should direct water outward over the water-resistive barrier, not behind it. Pay particular attention to the top of window and door trim and to the base of the wall. Details vary with the building assembly, so follow local code and manufacturer guidance.

Some siding assemblies use furring strips or another rainscreen approach to create a drainage and ventilation space behind the siding. Whether a rainscreen is required or recommended depends on the climate, wall design, code, and product instructions. If one is installed, it must be detailed to manage water and avoid blocking drainage at the bottom or other designed openings.

Maintain appropriate clearances from soil, paving, roofing, and decks. Exact distances can depend on local code and the siding system. Adequate clearance helps reduce splashback and moisture exposure. Also correct conditions that keep the wall wet, such as downspouts that discharge beside the foundation or vegetation pressed against the siding.

Install the New Cedar Siding

Before installation, check the wall for flatness and establish a level starting line. The first course affects the appearance of every course above it, so take time to set it accurately. Install starter material or a starter course if required by the siding profile. Keep boards aligned and maintain the manufacturer’s specified exposure and joint details.

1. Prepare the first board. Cut it to length, check the fit, and apply any required end-grain treatment or primer to cut surfaces according to the coating manufacturer.
2. Fasten each course as specified. Use the recommended nail type, length, and placement. Drive nails securely without crushing the wood or leaving heads excessively proud. Incorrect fastening can cause splitting, loose boards, or visible nail heads.
3. Stagger joints. Avoid lining up butt joints in adjacent courses unless the product instructions specify otherwise. Locate joints over framing or blocking as required by the siding system, and use the prescribed joint treatment.
4. Fit boards around openings. Measure carefully and cut cleanly around windows, doors, corners, and penetrations. Maintain the required clearances and make sure flashing directs water out over the siding or trim.
5. Finish edges and trim. Install corner boards and trim with the correct sequence and flashing details. Use sealant only at joints designed to be sealed; do not caulk drainage gaps or openings that must remain clear.

Many cedar siding profiles are installed with an overlap that shields the upper edge of the lower board. The required overlap and exposure are product-specific. Use a story pole or marked gauge to keep courses consistent instead of estimating each row by eye. Follow instructions for movement at board ends and joints; tightly trapping wood can contribute to buckling as moisture conditions change.

Finish and Maintain Cedar Siding

Finish the siding within the timeframe recommended by the manufacturer. If boards are factory finished, follow instructions for touch-ups and field-cut edges. For site-applied coatings, prepare the surface and apply primer or stain under suitable weather conditions. Moisture, temperature, and direct sunlight can affect adhesion and drying, so follow the product label rather than relying on a fixed rule.

Inspect the finished work for consistent coverage, properly seated fasteners, open drainage paths, and gaps around trim. Do not rely on a surface coating to hide poorly installed flashing or exposed end grain. Address cut ends and other vulnerable areas as directed by the coating manufacturer.

Routine maintenance can extend the life of cedar siding. Check it at least annually and after severe weather. Keep gutters clear, maintain ground and roof clearances, trim plants away from walls, and repair damaged paint or stain promptly. Clean siding using methods approved by the manufacturer; aggressive pressure washing can damage wood and drive water behind boards.

Common Cedar Siding Replacement Mistakes

• Covering up moisture damage: New boards will not correct a leaking wall. Find and fix the source of moisture before installation.
• Skipping flashing repairs: Missing or incorrectly layered flashing can allow water behind otherwise sound siding.
• Using the wrong fasteners: Incompatible or noncorrosion-resistant nails can rust, stain cedar, or fail outdoors.
• Ignoring product instructions: Exposure, overlap, joint treatment, and fastening rules differ by profile and manufacturer.
• Caulking every gap: Some joints or openings must drain or ventilate. Seal only where the design and instructions call for it.
• Disturbing old paint without precautions: Older painted siding may present lead hazards. Follow EPA and local requirements before sanding, cutting, or removal.

DIY or Hire a Siding Contractor?

Replacing a few accessible boards may be manageable for a homeowner with the right tools and carpentry experience. A full-house project is more demanding: it involves working at height, protecting the home from weather, coordinating flashing and trim, and diagnosing concealed damage. A contractor may be the safer choice for steep or tall walls, extensive rot, complicated architectural details, or lead-safe renovation requirements.

When comparing bids, ask what the proposal includes: removal and disposal, sheathing repairs, water-resistive barrier work, flashing, siding profile and grade, fasteners, finish, and cleanup. Confirm who is responsible for permits and whether the contractor carries appropriate insurance. A written scope that identifies water-management details can help prevent disputes and clarify whether concealed damage will be priced separately.

Useful references: The EPA’s Renovation, Repair and Painting Rule information at epa.gov/lead/renovation-repair-and-painting-program; the U.S. Department of Energy’s guidance on moisture control; and the siding and coating manufacturers’ current installation instructions. Local building departments can provide applicable permit and code requirements.