Sinking porch post

[paulm12]

I have a 15 year old small porch roof over the patio doors. The house is 25 years old. One side of the roof has dropped about 1-1/2". I want to level it out, mainly for resale reasons. I think the post concrete dropped over the first few years, the other side seems level from the house.

- the concrete for the posts is 42" deep, with anchor bolts, per the permit.
- the post is PT 4x4, wrapped in cedar, then top and bottom decorative cedar pieces as well.
- there are 2x6 joists 16" OC and 2x6 rafters 16" OC.
- the roof is around 8 feet long and 4 feet deep.
- the header is (3) 2x6's with 2 of them sitting on tenon joints on the post. The tenons appear to be around 1" deep, so the header boards sit partially out from the post.

I can think of several options, and I am probably over-thinking this:

1. cut the nails in the post base, and then raise the header, and just add a 1-1/2" shim under the post? This would be the simplest and also the minimum disturbance to the structure. How best then to secure the shim piece?
2. remove the 2 lag bolts at the top of the post, raise the header, and redrill for the bolts. I don't like this because of adding holes to the post tenon 1-1/2 inch above existing holes.
3. Replace the post. The safest option.

Will I have an issue getting the post up over whatever bolt and/or nut is on the concrete anchor? ie is there a cutout in the end of the post there? I want to raise the header the minimum amount necessary.

thanks for any comments.

 

[SGKent]

were it me I would temp brace the roof, pull the column, chip the concrete and drill it for a a couple pieces of small rebar then add the needed amount of concrete with a new plate and then put the post back. Alternatively you could use a jack to lift that piece of concrete out and re-pour. The issue that I see is the bottom of that post is going to collect water and then rot if you don't raise it up some. If you live in an area where that additional concrete might break up because of the freeze cycle then that may not work.

 

[strutaeng]

I have a 15 year old small porch roof over the patio doors. The house is 25 years old. One side of the roof has dropped about 1-1/2". I want to level it out, mainly for resale reasons. I think the post concrete dropped over the first few years, the other side seems level from the house.

- the concrete for the posts is 42" deep, with anchor bolts, per the permit.
- the post is PT 4x4, wrapped in cedar, then top and bottom decorative cedar pieces as well.
- there are 2x6 joists 16" OC and 2x6 rafters 16" OC.
- the roof is around 8 feet long and 4 feet deep.
- the header is (3) 2x6's with 2 of them sitting on tenon joints on the post. The tenons appear to be around 1" deep, so the header boards sit partially out from the post.

I can think of several options, and I am probably over-thinking this:

1. cut the nails in the post base, and then raise the header, and just add a 1-1/2" shim under the post? This would be the simplest and also the minimum disturbance to the structure. How best then to secure the shim piece?
2. remove the 2 lag bolts at the top of the post, raise the header, and redrill for the bolts. I don't like this because of adding holes to the post tenon 1-1/2 inch above existing holes.
3. Replace the post. The safest option.

Will I have an issue getting the post up over whatever bolt and/or nut is on the concrete anchor? ie is there a cutout in the end of the post there? I want to raise the header the minimum amount necessary.

thanks for any comments.

I'd replace the post. Shore with double 2x4 and cut her lose. The biggest thing with the shim is that if there is any wind uplift, there's nothing to resist that except the self-weight of the porch. Besides, the post bottom connection is looking pretty bad.

I wonder why it sank so much? The other side has not heaved, has it? Poor compaction on the bottom of the footing before pouring concrete?

 

[zak77]

I'd think the sinking was from improperly compacted fill under the pier. You could take a short-cut and simply disconnect the post from the post connector, then jack up the porch till it's level, then add a shim under the post and resecure everything back together. You may want to replace the post connector while you're at it since it's seen better days. I did that to a deck where one corner was sinking 3.5" and a PT 4x4 got it level once i jacked it up. 8 years later and it's still level.

 

[kbs2244]

Before getting in too deep, I would have a mud jack guy come by and have a look.
They typically will take in a job that they cannot do satisfactory.

 

[paulm12]

thanks all for responses

Merlin: I am in Chicago area, so freeze and thaw is constant concern. I would not want to replace just a part of the pier. And digging the pier out would be a pain since it is so close to the patio.

Struetang: yes, I am thinking the settling of the pier was due to compaction of the soil. You can kind of see that the slab itself has settled an inch or 2 in that area.

Zak: yep, I think you are right. I need to determine how to remove the existing connector without disrupting the concrete pier.

kbs: I was kind of wondering about mud-jacking, they do slabs easily, not sure if they can reach down 42" for the pier though.

Is there a taller (??) type of post connector that I could add to the existing concrete securely to raise up the post a bit? Then replace the post.

Thanks again.

 

[K'ledgeBldr]

This would be the proper anchor-
https://www.fastenersplus.com/Simps...eFNDIKGzyEZZQvJew4g1EgN1gXbT5LbBoCFTAQAvD_BwE

That's 1" of your displacement- the rest could be done with a PT shim.

If it had been me- wouldn't have built it that way to begin with. The posts should be on the upper tier- and the roof supported with a drop beam. With the posts on the upper tier of the porch they wouldn't be subjected to weather as much, and the weight of the porch roof would have been displaced over a larger area- probably eliminating any sinking.

 

[Fatboy148]

Raise it slowly, over time. It took 15 years to settle, don't bring it back to level in 30 minutes!

I would replace both posts and the ceiling while there to make it all look of the same vintage. Whatever you do, document it well with pictures (both before, during the repair/before you close it back up and when you are finished with the repair) because dissimilar materials or finishes will surely raise questions when the housing inspector looks at it prior to closing of the sale. Showing that you fixed this issue properly and didn't "cob" the job might make everyone more at ease when looking at the rest of your place.