How To Repair Rotted Wood Siding Or Replace It

How To Repair Rotted Wood Siding Or Replace It

Does this sound familiar? You have a well landscaped yard with beautiful flower arrangements placed carefully along your property. Your window trim, porch and fence have all been well maintained as well. There’s one problem though — your wood siding on the exterior of your house is falling apart and rotting. Well, don’t worry because we’re here to help you figure out how to repair rotted wood siding or replacement it entirely! Read on for all the details.

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Materials Needed To Repair Rotted Wood Siding

  • Safety Glasses
  • Chisel
  • Paint
  • Paintbrush
  • Measuring Tape
  • Replacement wood siding
  • Nails
  • Hammer
  • Circular Saw
  • Epoxy & Expoxy Primer
  • Utility Knife
  • Acrylic Caulking
  • Rag
  • Pencil
  • Putty Knife
  • Pry Bar
  • Borate
  • Sand Paper

1. Wood Siding Repair: Patch work 

  • If you have to repair rotted wood siding, you may be able to patch it. It all depends on how severe it has rotted out.
  • Find a small part of the wood siding and remove the damaged section, if it is visible enough to know the rot is in a specific place. It is important to patch the wood siding as soon as there is evidence of rot. This helps to prevent the rest of your wood siding from being completely rotted through.
  • After you have removed the part of the wood siding, make sure you have clapboard that will fit in flawlessly with your existing wood siding so it won’t look out of place. Use the removed rotted piece of wood siding as a template. As it has the exact measurements for the replacement siding.
  • Use a paintable acrylic caulking around the opening on the side of the house. Try to slide the thinner side of the clapboard underneath the board above the opening of where you cut from. Then carefully push the board in tightly. Use 8d nails into the wall studs ¾ inch up from the bottom edge of the replacement board and also the bottom edge of the piece above it. Do this carefully as you don’t want to split the wood.
  • You can then cover up the nails with the acrylic caulking. Wipe away any excess with a rag. Then you’ll want to prime this patch and let it dry. Once dry, paint it the same colour as your existing wood siding with two coats. Allow it to dry overnight and apply a second coat! 

2. Wood Siding Repair: Replace Severely Decayed/Rotted Wood

  • If you have to repair rotted wood siding or siding that’s decayed severely, mark the start and end of the rot off with a pencil. Put on your safety goggles and cut out the rotted wood siding piece using a circular saw. Use a hammer to get rid of any nails that hold the wood to the structure. Using a chisel, finish cutting the wood and detach it.
  • Now you’ll need your replacement piece that you have measured to fit in perfectly. And just like you would patch like the steps above! Slide in the replacement carefully and nail it together with 8d nails. Prime regularly, let dry and paint the replacement piece with the same colour as your existing wood siding with two coats. Let it dry overnight.

3. Repair Rotted Wood Siding with Epoxy

  • Like the other two steps, get rid of any rotted siding either with a chisel, saw or hammer/pry bar and inject borate into the hole. Borate is a wood preservative and it can be drilled halfway into the wood to be sealed over with epoxy. Borate basically seeps into the wood and will minimize rot/decay in the future.
  • Using an epoxy primer – brush it on the wood that has been exposed. Allow a 10-20 minute dry time and then wipe away any excess with a rag.
  • Apply the epoxy with a putty knife and sculpt carefully overtop the primed area and allow to dry.
  • Prime with an acrylic primer and paint over the epoxy with two coats of paint.

Last top hints: 

  • Smaller cracks or holes in your wood siding should be sanded and then filled with wood putty. Then they should be sanded smooth again, primed and painted as well.
  • Sunlight will break down Epoxy, so be sure to paint it as soon as it has dried. Especially, if you are completing this project in high sunlight.
  • Use a two-part epoxy primer and paint for optimal results. 

More interesting blogs related to ” How To Repair Rotted Siding Repair Or Replace It “: 

  1. How To Pick Exterior Paint Colours  
  2. Painting The Garage: Everything You Need To Know
  3. The Best Time Of The Year To Paint The Exterior Of Your House
  4. Tips For Painting Wooden Exterior Trim 

If you have to repair rotted wood siding at a level that you just don’t think your patience will tolerate – then give Home Painters Toronto a call and we’ll happily do it for you! Call us NOW at 416-494-9095 or sned us an email at

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