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Discussion Starter · #1 ·


I have no real experience with this, but logically, I'm thinking I need to pack in a solid material under the exposed concrete on either side of the post. Use a temporary post on either side of the sinker. Remove the sinker and dig a deeper and wider base underneath and then probably replace the post itself. If this is correct, my only question is what is the best material to be using under the post and under the exposed surrounding concrete?

Thanks.
 

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Yes, I agree with you, support the deck and redo the support. We don't know your location. So we don't know if you're dealing with heavy frost line etc., which will determine how deep and wide support should go.

Is it just that support that failed or are others questionable as well?

Can you post a couple pics from further away so the pros can see the whole deck. Thanks.

Pros will be along shortly with more advice/suggestions.
 

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Discussion Starter · #5 ·
I am in the southern interior of BC, Canada. It can get as cold as -10F here, but this year it hasn't been below 5F. I'm pretty sure I have noticed the post sinking moreso in the past 10 days or so with the snow melt which makes sense I suppose. There are 4 other posts and they all seem OK.
 

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I can't tell from the photo if the post is sinking or the concrete around it is heaving. The best way to tell is to shoot grade using a level. If the post is sinking, that indicates a failure of the footing, which will then have to be replaced when you replace the post. If the concrete is heaving but the post is not sinking, then you may only need to replace the post (assuming the post is rotting).
 

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Looking at the base of the next blue post back (to the left in last pic), I believe I see a tapered pier block (12x12x8 ?). It looks like the deck was built on piers and the slabs poured later.

My guess is that they just dug holes to set the pier blocks in, setting them with about 1/2 the height exposed above grade. I would guess there is no footing under them.

While the settling post needs a new pier, I would replace them all. After you firm that one up, the next "weakest link" will be the next one to settle.

You may have additional movement problems with those slabs. They were poured individually without any reinforcing between them. I am fairly certain I can see the 2x4 form board still in place between them.
 

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Discussion Starter · #9 ·
I can't tell from the photo if the post is sinking or the concrete around it is heaving. The best way to tell is to shoot grade using a level. If the post is sinking, that indicates a failure of the footing, which will then have to be replaced when you replace the post. If the concrete is heaving but the post is not sinking, then you may only need to replace the post (assuming the post is rotting).
It's definitely sinking. The joist above the temporary post was sagging big time.
 

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I have no real experience with this, but logically, I'm thinking I need to pack in a solid material under the exposed concrete on either side of the post. Use a temporary post on either side of the sinker. Remove the sinker and dig a deeper and wider base underneath and then probably replace the post itself. If this is correct, my only question is what is the best material to be using under the post and under the exposed surrounding concrete?

Thanks.
I dont know about the soils usually on new houses they test and give recommendations for compaction or replacement. Maybe if you ask over in the concrete section you will get better advice for size and subsoil.

as far as design goes make sure your finish concrete pad for the post is 6" above grade and then use a post base. if you have a hammer drill the drill in bases are easier to install.

these ones are nice. they keep the wood up off the concrete.
 
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