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maine 08-27-2012 05:20 AM

Deck Posts Slipping Off Slabs - Help? (Pictures included)
4 Attachment(s)
I moved into a new (to me) house and found that due to the freeze/thaw here in Maine that over the last 15 years the deck posts have shifted. [See pictures attached]. One is about to fall off the 12" concrete pad. I want to dig new holes and use 4' sonotubes with concrete and attach the posts to that.

I'm a DIY newbie (first home). Any tips? Does that sound like the right way? I don't know if there was wisdom in not bolting the deck posts to the concrete or whether it was just being quick about doing the job.

Any and all tips/help/suggestions would be much appreciated.

Trucon01 08-27-2012 09:07 AM

Well that was done wrong... I'm no expert, but you may have to support the whole thing and re-do each of those footers and put in a metal post in the cement hold the posts in place.

The woods posts should never touch the concrete footer.

Are those footers even in the ground or just laying on top of the soil???

Oh my god, I just looked again. Look at picture 1 (top left). Its just a 4x4 under the joist holding that up. Do yourself a favor and DO NOT walk on there until you get this fixed. The top if coming off the joists and the bottom is coming off the footer!!!!

joecaption 08-27-2012 09:14 AM

A 2, story deck should have had 6 X 6's not 4 X 4's. Those look like just post blocks, not legal for a two story deck.
You need Sono Tubes set to below your frost line. 2' diam. tubes would be more then enough, and post blocks to hold the post in place and keep them from direct contact with the concrete.

I'd be taking a close look at how they flashed the ledger board to the side of the house to see if there even is any since they messed all the other stuff up.
Did they also build the deck even with the doors threshold. If they did it's a sure way to get water under the threshold and take out the sub flooring or more.
Code calls for at least 4" below any door openings.
There's also no gripable hand railing.
That railing post in the corner was also installed wrong.

Thunder Chicken 08-27-2012 09:32 AM

That deck is a good knock away from a collapse. Seriously, I'd tape it off and go in the house some other way until that is fixed. Be careful.

CoconutPete 08-27-2012 10:23 AM

Yeah ... don't walk on that deck until you address these issues. Sonotubes a definite yes on this one.

Did you have a home inspection?

NewHomeDIYGuy 08-27-2012 11:10 AM

As other said, deck definitely looks pretty sketchy. What worries me is that it looks like the main part of the deck (not the stairs), looks like it only has posts supporting the corners, rather than at the two "ends" of the deck farthest from the house, and it doesn't look like there's a beam, just the joist going to 4x4 posts..

wkearney99 08-27-2012 11:55 AM

Support it temporarily, dig out the old incorrectly done footers, replace them with ones dug to your local code required depth with a flared bottom and put new 6x6 posts up to the deck. Yeah, it's a lot of work because someone else did it wrong. But there's really no way to 'fix' it without replacing those incorrectly done footers. As to whether the rest of the deck is worth saving, that depends. The pictures don't show enough to say one way or the other. But bear in mind the cost to try and fix that one might be more than just replacing it completely. The labor costs to work around an existing deck would likely be a lot more than what a whole one might cost. Unless you're doing the work yourself and aren't worried about your time.

orange 08-27-2012 01:00 PM

Agree generally with what has been said.
When redoing, you might consider these big foot supports - I have used them and embedded metal brackets to attach 6x6 and they work great.

Again, check your local codes as has been suggested.

wkearney99 08-27-2012 01:18 PM


Originally Posted by orange (Post 997505)
Agree generally with what has been said.
When redoing, you might consider these big foot supports - I have used them and embedded metal brackets to attach 6x6 and they work great.

Yup, the idea being you put the 'bell end' of it down deeper than the frost line. This way when the soil above heaves it won't be able to pull up that flanged part.

Docks in water have this same trouble in the winter. The water freezes around the post, then the tide rises, and the posts get jacked up. But the weight of the ice usually isn't enough to push the post back down when the tide drops. Some might, some might not. The same sort of thing happens with soil. The water in the ground freezes and that ice causes the soil to expand. It has nowhere to go but up so it pushes on anything on top or alongside of it. When footers are deep enough, below the depth of things freezing, they resist being pulled up that way. The flared end on the bottom makes them even more resistant to lifting.

But even with the flare at the end it still has to be beneath the local frost line. This usually means either a LOT of shoulder and back-breaking labor with a manual post hole shovel OR you need enough clearance to get a powered digger in there. And by the time you do enough to support an existing deck to get clearance for a digger, well, you might as well just rip it down and start over.

drtbk4ever 08-27-2012 02:30 PM

Hi Maine,

It sure looks like those concrete pads are just sitting on the surface.

I'm hoping you could get a couple photos of where the deck attaches to the house from the side and from underneath. Perhaps a photo of the outside edge of the deck from underneath too.

That will help the guys here judge the contruction methods of the deck to provide you more advice.

Thanks, and welcome.

maine 08-30-2012 08:44 AM

Thanks to all for replying and providing helpful feedback. Sounds like it's even worse than I thought, which wasn't good to begin with.

I am going to take pictures when I get home from work tonight of the ledger board, the underside, the upper deck where it meets the door, and others.

Any special concrete that I should use for a deck? Quick setting OK?

I think that the deck is salvageable once I fix the footers, but I'd be interested to see what you think after taking a look at the other pictures.

Again, thanks to all of you!

GBrackins 08-30-2012 09:08 AM


check out this link, it is the "Prescriptive Residential Wood Deck Construction Guide" by the American Wood Council based upon the requirements of the 2009 International Residential Code. It will provide you with the prescriptive requirements for a code compliant deck.

maine 08-30-2012 05:03 PM

6 Attachment(s)
Hi everyone -

So here are some more pictures. Any additional thoughts/considerations after seeing more details?

Fun Labor Day project ahead of me!

Thanks again!

wkearney99 08-30-2012 05:56 PM

Looks like frost heave pulled up on the stairs too.

GBrackins 08-30-2012 06:03 PM


isn't it the first photo, top left?

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