How to Replace or Repair a Rotted Deck Post
What are you supposed to do when you notice rot on your deck posts? Should you scrap the whole deck and start fresh?
According to Angi’s List, the average cost to build a new deck is nearly $8,000, compared to the average deck repair cost of $2,000. You can simply perform a deck post repair or replacement, saving your wallet from a costly total deck replacement.
Read on to learn how to repair or replace a rotted deck post.
Can You Repair Rotted Wood Deck Posts?
Yes, you can fix rotted deck posts, which is a relief, since deck posts are the most crucial part of your deck’s infrastructure. In many instances, you can even complete this home improvement project yourself.
If you aren’t sure of the extent of the damage on your support posts, ask a professional handyperson for advice. This way, you can guarantee a deck post repair is right for you.
When Should You Repair a Rotted Wood Post?
Regardless of the wood rot your deck is experiencing, both wet rot and dry rot are destructive.
You can repair the rotten deck pieces if the decay is in a small area. Just cut out the rotted area and create a new piece to fit. This is a safe method if you use metal post brackets for support.
Since replacing decorative posts can be incredibly difficult, especially if they were custom-made, you would most definitely want to try repairing them.
When Should You Replace a Rotted Deck Post?
The most obvious time to consider a deck post replacement is when the structural integrity of your deck is at stake. For example, if your deck has rotted in many areas or has damage beyond repair, you want to replace the posts.
But what if your deck is on concrete footers? Your deck is safe from rot, right? Sadly, this is not so.
Decks on concrete footings can rot, especially decks close to the ground. This is because moisture under the deck will build up and create the perfect environment for rot to thrive. In fact, if the bottoms of the posts are in concrete, they are highly susceptible to decay.
Concrete holds moisture, causing the wood to rot prematurely. Therefore, you will need to remove the entire concrete footing and start anew.
However, your deck posts don’t need to be in disarray to consider replacing them. You might want to change them out for other reasons. Homeowners can also replace posts in the following scenarios:
- To change the entire aesthetic of the deck, from new colors to different railings
- To create usable storage space beneath the deck
- To switch from wood to composite materials
How Do You Fix a Rotted Deck Post?
So you’ve decided to fix your rotted deck posts. Will you do it yourself or call a professional?
For the DIY route, follow the steps below.
For a rot repair, you need the following tools:
- Claw hammer
- Putty knife
- Sanding block and sandpaper
- Utility knife
Next, gather these materials:
- Epoxy consolidate, paste, and resin
- Filler (polyester or epoxy)
- Wood hardener
Steps to Fix Your Rotted Deck Post
After gathering the required tools and materials, remove the rotten deck boards. Try your best not to damage the surrounding wood. If you need to remove an entire deck board or handrail, you can replace it later. Note that if the rot affects a deck joist or beam, you must install new fasteners and reinforcements.
Next, apply the filler or wood hardener. Once in place, you want to shape and smooth it. When you’re happy with the shape, you can use stain, so the new wood matches the rest of the deck. Finally, seal all new wood. This protects the wood from moisture.
If you aren’t entirely confident in your repair skills, check out DIY deck repair tips from Decks & Docks to guide you in the right direction.
How Do You Replace a Rotted Deck Post?
It will take a bit more elbow grease if you need to replace an old post. The contractors at This Old House recommend having at least mid-level carpentry skills to install your new post. If you lack the skills for the job, it’s best to hire deck professionals to fix it for you.
The tools you need for a deck post replacement are as follows:
- Hammer drill
- Impact driver
- Impact wrench
- Masonry bit (1.5 inches)
- Miter saw
- Pry bar
- Reciprocating saw
Don’t make the mistake of using a handheld screwdriver for deck-related projects. Power tools will save you time and effort (and your arms) during the project.
You also need to gather the following materials:
- New lumber beams
- Screws and nails
You may also need new concrete footings depending on your deck’s structure.
Steps to Follow
- First, you need to install temporary posts below the outer deck beam. Cut free any diagonal bracing and pry out existing nails. Then, pull out the old post.
- Next, set and secure a metal post base on your concrete pier. Cut a new post to fit between the post base and underneath the deck’s frame.
- If you have concrete footers, you must make a hole where the old post was. Insert a sonotube into the hole to ensure the hole is level.
- Then, pour the new concrete and install a j-bolt to hold the saddle bracket. The bolt must be level and plumb.
- Finally, you can install the new post. Secure it to the deck beam and remove the temporary supports.
Guarding Against Future Damage
To avoid rotted decks altogether, there are some steps you can take in prevention. Here is how to keep your deck posts from rotting.
First, consider choosing different deck post materials, like pressure-treated wood or composite decking. They are more moisture-resistant than traditional wood.
Second, practice regular deck cleaning. This keeps damp debris from building up.
Third, you can use wood preservatives, such as:
- Alkaline copper quaternary (ACQ)
- Copper azole, copper naphthenate, or copper-HDO
- Polymeric betaine
These will help to make your deck rot-resistant.
Find the Materials and Knowledge Needed for Your Project
Your deck is the main feature of your outdoor space, so if you need a deck post repair or replacement, let the experts help.
Contact us at Decks & Docks for help on your next deck project. Our professionals will swiftly fix your deck so you can enjoy it again in no time!
- About the Author
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Brian has worked for Decks and Docks for over ten years. He worked his way up the ladder, started as our Wilmington Branch Manager, opening that store for us in 2013. Brian was then promoted to our first Regional Manager and oversaw six stores before being promoted to our Corporate Office as COO. His vast experience in our industry makes him a valuable asset to the team and to our customers.