Rotten deck posts

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Forum topic by willhime posted 05-04-2017 03:59 PM 1738 views 0 times favorited 7 replies Add to Favorites Watch
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146 posts in 2140 days

05-04-2017 03:59 PM

Topic tags/keywords: question resource tip trick cedar joining

We’re trying to figure out what to do with a rotten top deck post. It’s only the top 3 inches so it’s hard to just pull it out and replace it but I’m willing to do that. The problem is the post is notched out to support 2 edge boards. One guy suggested scarfing the top with a 45 angle and try to blend it in. Another theory was to cut it flush then put another on top with a support cradle or bracket. Suggestions ?

-- Burn your fire for no witness

7 replies so far

View JCamp's profile


1035 posts in 1151 days

#1 posted 05-04-2017 04:50 PM

Personally I would cut the top couple inches off each post making sure they are all the same height and level then wrap the deck with a 2×6 at a few inches off the deck another at the top and another I the middle then take a 2×8 an lay it horizontal along the top as a railing that you can hold on to or set stuff on. Unless there is a lot of other stuff going on replacing the posts is a lot of extra work, time and money

-- Whatsoever thy hand findeth to do, do it with all thy might

View jerryminer's profile


960 posts in 2042 days

#2 posted 05-04-2017 11:08 PM

You can cut the post down and do a half-lap joint:

But you should be aware that it’s likely that this is not the only post with problems.

Wood rot is a fungus, and the fungus is growing into the wood that still looks OK. You should cut several inches into “sound wood” to remove the fungus. Chemical treatment may also be wise.

-- Jerry, making sawdust professionally since 1976

View canadianchips's profile


2632 posts in 3598 days

#3 posted 05-05-2017 12:28 AM

The proper thing to do is replace the whole post.
Your post is support for railing.
To add a piece might weaken it.
As someone previously mentioned. Check the other posts as well.

-- "My mission in life - make everyone smile !"

View mrg's profile


860 posts in 3600 days

#4 posted 05-05-2017 02:55 PM

Your better off replacing. If the wood is rotted it will keep going. Pay once cry once. If the height is wrong and you go to sell you will have to replace. If the insurance company decides to check on the property which they do from time to time and it’s not to code they will ding you.

-- mrg

View Kelly's profile


2624 posts in 3545 days

#5 posted 05-05-2017 03:34 PM

Yet another vote for replacement.

When I replace fence post that were secured with concrete, I used a slow drill and auger and spade bits to break up what was in the concrete, then vacuumed it out, rather than dig out the concrete and disturbing the settled soil. You’re dealing with tight quarters, so may not get away with that, but, if you can….. you’d be able to drop a new post into the existing square hole, if the post is at the same moisture content (the swelling issue).

View builtinbkyn's profile


2999 posts in 1541 days

#6 posted 05-05-2017 03:45 PM

It’s difficult to tell from the pics, but that post looks wasted pretty far down. Johnny Cochran says – Replace if that the case. If not, then the scarf/half lap joint is fine as posted above. You may want to cut the skirt back a few feet to either side of the offending post so there’s no splice behind where the skirt will cross the post. Reinforce the splice under the deck with a 2×4 and then bolt thru the new and old section of post to the skirt.

-- Bill, Yo! Brooklyn & Steel City :)

View BurlyBob's profile


6883 posts in 2866 days

#7 posted 05-05-2017 05:06 PM

Yeah, I’m gonna vote to replace it. It’s just about the same amount of work as a repair and the end result is a better piece of wood.

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