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How to Repair Wood Rot on Your Outdoor Deck: A General Overview

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Currently employed as a physical therapist assistant specializing in elder rehabilitation and education/training.

Wood Rot: A common nemesis on most homes.

If you've owned a home for any length of time, more than likely you've experienced wood rot in some way. For us, it's been our deck.

Built of cedar over 14 years ago, our deck has provided quite the challenge when it comes to wood rot repair. This hub will briefly overview my latest deck repair project. Hopefully it will assist you as well by keeping your deck safe and wood-rot free!

The Process:

The following pictures tell the story: lots of wood rot and lots of time spent repairing it. Here's a general guideline for basic wood rot repair that can be modeled for most other wood rot issues.

Here's the order for tackling this project:

  • Carefully remove primary rotted wood. Remove only what is necessary as you'll need as much solid wood as possible to reinforce. Examples of primary wood pieces can be (not an exhausted list): Deck and stair treads, stair stringers, trim boards, window trim, siding, fascia, etc. Basically anything made of wood exposed to elements or potential water damage.
  • Remove additional wet and dry root with an appropriate tool. Make sure ALL of the rot is removed. If there's not enough viable wood remaining, you'll have to replace the entire wood structure.
  • Protect exposed wood with a suitable wood hardener and allow to dry.
  • Fill void/cavity with an appropriate wood filler and allow to dry.
  • Sand and level to appropriate height and dimension.
  • Replace rotted wood pieces and secure with appropriate exterior wood fasteners; in this example, stair treads are being replaced.

All in all, not a lengthy process, but it does take time to do it properly to avoid future wood rot.

Ends of the cedar stair treads after removing from partially-rotted stringers. Not a safe step to say the least!

Ends of the cedar stair treads after removing from partially-rotted stringers. Not a safe step to say the least!

Cavity created after removing the rotted wood. I used a small, ice-pick-like tool to remove the rot. Make sure all the rot is gone, or you'll be doing this again later.

Cavity created after removing the rotted wood. I used a small, ice-pick-like tool to remove the rot. Make sure all the rot is gone, or you'll be doing this again later.

Another image of a partially rotted stringer and adjacent skirt board. Luckily, there was enough solid wood remaining to fill and attach additional support.

Another image of a partially rotted stringer and adjacent skirt board. Luckily, there was enough solid wood remaining to fill and attach additional support.

Still more rot with all the loose debris removed with compressed or blown air.

Still more rot with all the loose debris removed with compressed or blown air.

Wood hardener used to treat good wood exposed by cavity.

Wood hardener used to treat good wood exposed by cavity.

Applying the wood hardener.

Applying the wood hardener.

Wood hardener after drying for a few hours.

Wood hardener after drying for a few hours.

Repaired stringer and treated wood rot.

Repaired stringer and treated wood rot.

Wood filler chosen to fill voids. You can use other products as well; I've just had good luck with this as it drys quick and sands easily after curing, not to mention it cleans up easily with water.

Wood filler chosen to fill voids. You can use other products as well; I've just had good luck with this as it drys quick and sands easily after curing, not to mention it cleans up easily with water.

Wood filler after drying and shaping.

Wood filler after drying and shaping.

Another view of cured wood filler with stringer reinforcement attached.

Another view of cured wood filler with stringer reinforcement attached.

Stringer reinforcement with liquid nails as a binder.

Stringer reinforcement with liquid nails as a binder.

Stringer reinforcement in place with 3" deck screws used to attach.

Stringer reinforcement in place with 3" deck screws used to attach.

New treads solidly in place and ready for use. No more dangerous steps!

New treads solidly in place and ready for use. No more dangerous steps!

Tools used for this project:

  • Replacement wood treads: Pressure treated 2 x 6 x 8 and 2 x 6 x 10 as needed.
  • Power miter or circular saw
  • Tape measure
  • 3" deck screws (amount will vary)
  • Power drill
  • Liquid nails approved for exterior use
  • Boring or appropriate wood removal tool; choices are many.
  • Wood hardener with application brush
  • Wood filler with application tool; I used a 1" putty knife
  • Sand paper and 3/4" chisel to shape wood filler
  • Blower capable of removing all debris from cavity after rough removal; I used an air compressor with air nozzle attachment.
  • PATIENCE as this project takes a fair amount of time!
  • Good luck!

© 2018 Rob Jundt

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