12

Summary - the post size seems questionable. Even at 12", it might have been insufficient. It depends very much on your soil type. The remainder of this answer is a huge estimate based on lots of assumptions. For something like a residential deck the reason the size of a footing is important is not because of the strength of the concrete itself, but ...


4

This site prefers not to provide 'call a professional' answers and I might receive some less positive reception for this answer, but this is a case where I think that it is appropriate. My suggestion is to hire a local structural engineer to do a site visit and provide you with their opinion of the situation and additionally, if you prefer, a DIY fix ...


3

If you are willing to dig some big holes, while stabilizing the piers so they don't fall on you, and do some drilling you might be able to solve this more simply. Hmm - actually, those (10" dia x 30 inch tall) calculate out to only weigh 204 lbs or so, if I didn't slip a digit, so you might even be able to manhandle them around. The piers you have are ...


2

Like Ed Beal suggested in a comment, you mostly need to drive your shims in more assertively. However, I'd use plenty of construction adhesive as well. Remove the shims now in place if they'll come out with a little effort. Blow or vacuum out all dust and debris. Inject plenty of heavy-duty construction adhesive into all gaps. Firmly drive pressure-...


2

Support either side of each post, cut it off, insert a steel stub base or pour a new concrete base to a height slightly above the planned slab, pour the new slab. Or, just make sure the "expansion joint" around each post is actually around each footing, boxing out the whole area, and fill with pea stone or marble chips after pouring the slab. Or skip ...


2

"Pressure treated wood" isn't one thing. It's many things. Some is rated for ground contact or below grade use. Most isn't. You'd need lumber that is. You won't keep it from getting wet underground, but you can keep it from being constantly saturated by giving the concrete sleeve a drain at the bottom. One strategy is to set the post on gravel and ...


2

If your posts are pressure treated, you can set the concrete level to grade. If the posts are not pressure treated, I would set the top of concrete at 8" above grade. more would not hurt. Also use metal fasteners that hold the post up off the concrete 1" in either case.


1

Cleanest is probably to use a core drill to cut a hole for the post and then use a vacuum excavator to dig the hole. Neither step is particularly DIY If you drill a 6" hole and then use a angle grinder with a concrete blade to enlarge it to 6" square that might be slightly neater than the 9" hole you'd otherwise need. If there are no lateral ...


1

Your question seems to be simply whether you can bell out the hole for the footing. Yes, you can. Footing specifications are for the footing structure itself, not where or how you access the space occupied by the footing. The opening in the patio would only need to be large enough for concrete to pass through, but obviously you'll need to get a post-hole ...


1

The biggest problem with that approach is that the slightest lateral movement of the post is going to crack the concrete. It’s just too much leverage against a brittle substance. Since you are bothering with a hole and concrete, I would suggest using anchors. Pretty easy, just fill the hole and insert the anchor. Let it fully set and build. This keeps the ...


1

In my last house, I built a very large deck and all the uprights were installed in concrete that were buried 3' minimum into the soil below. The deck was very solid and done to my perfection. 20 years later when I was selling that home, the treated 4X4's that were the uprights were soft and seemed rotted about 1/2" into the wood. I was told by a home ...


1

I think your approach is right on target. Follow FreeMan's suggestion to embed bolts in the footings to attach your base plate for each post. It's unlikely that you'll have serious frost issues as long as you: Make sure your support piers are below frostline - in my area it's 36". Be certain to properly lay the patio base with a solid, self-draining ...


1

I use the extreme cases when preparing footings, the map I looked at showed 36” would be an extreme condition and as such constant frost heave at that depth will not be a problem. As far as your piling I have done quite a few homes and never shaped the bottom other than flat, if using a auger to drill your holes they do end up with a bit of a point. I ...


1

I doubt if it’s a retaining wall. Also, I doubt if it was constructed at the time the house was built. I’ll make several assumptions and you let me know if I’m wrong. 1) The first picture shows the upper wall with a sole plate mortared to the top of the wall. This indicates the wall was poured up close to the existing wood floor system and then the sole ...


1

I like to put bring the footers 6-8 inches above grade. I go on the higher side if its on a slope. Much more than that and you are buying a lot of concrete.


1

There are two grades of pressure treated lumber: 1) Above Ground Use, and 2) Ground Contact. 1) Above Ground Use is used for deck railings, building wall sole plates, etc. 2) Ground Contact lumber can be on the ground or in the ground. If your concrete piers are within 6” of the ground, they are considered “Ground Contact Use” by the Code. Ground ...


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