How to Replace Siding

Refresh your house's exterior by replacing damaged siding

Has some of your siding begun to rot while the rest is still good? Don't replace all the boards. Follow these easy steps and just replace the boards that are rotted.

By the DIY experts of The Family Handyman Magazine

Replace rotted siding

When hardboard siding is installed and maintained correctly, it can hold up for 30 or 40 years. But without proper attention, isolated areas can begin rotting in only a few years, especially near the foundation. Water splashes up from the ground, frequently soaking the vulnerable bottom edges. The paper face then flakes off, exposing the dark brown inner layers, and each soaking accelerates the rotting.

Replacing these rotted areas takes only a few basic tools and a few materials, but it can make a huge improvement in your home's appearance. Hardboard siding doesn't cost that much, so it's often worth it to replace an entire course. Doing this helps you avoid unnecessary butt joints.

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Make your repair last

  • Prime the back and edges of the new siding. Thoroughly paint all exposed edges and grooves.
  • Do not drive the nails flush or countersink them. The heads will break the paper face, allowing water to soak in and deteriorate the siding. Caulk any nailheads that break the paper face.
  • Leave a 1/8-in. gap at corner and butt joints. Seal these joints with a 35-year, paintable acrylic latex caulk.
  • Prevent water from splashing on the siding by installing gutters or repairing leaky ones. Also, adjust lawn sprinklers so they don't hit the siding.
  • Where siding meets a roof, it will rot if the siding touches the shingles. When you replace these boards, make sure you have good flashing along the joint. Install the new siding so there's a 1-in. gap between siding and shingles.
  • Consider replacing rotted areas with fiber-cement siding. It's 1/8 in. thinner than most hardboard, but it works in many cases, has a comparable cost, is highly rot resistant, and carries a 50-year warranty. For help finding a dealer in your area, call James Hardie Products (888-542-7343 or jameshardie.com) or ABTco (800-265-9829 or abtco.com).

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Caulk gun
  • Circular saw
  • Combination square
  • Drill/driver, cordless
  • Drill bit set
  • Extension cord
  • Extension ladder
  • Hammer
  • Hearing protection
  • Level
  • Pry bar
  • Safety glasses
  • Sawhorses
  • Scribing tool
  • Speed square
  • Tape measure
  • Utility knife

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • 10d Galvanized box nails
  • Paintable acrylic latex caulk
  • Replacement siding boards