Deck Construction

[Allan Dozier]

As Marc said, wood beneath the ground is fine depending on the treatment. If you have trouble finding what you need, contact some dock building companies and ask where they get their wood.

[Rich Engelhardt]

George,
I've heard through he contractor grape vine that:

A tried and true method is to dig the hole below the frost line in your area, set a SONTUBE of the chosen dia. - 6" for a 4x4 post , 8" for a 6x6 post, fill with concrete so that the concrete is above grade a few inches to 6" (ideally all at a relative level height but that it nitpicking) then set a PT post on top of that using a Simpson Strong Tie post base -

What Sam says is code now in most cities in NE Ohio.
The local building department (as mentioned) can give you the right answer.

[George Bokros]

George,
I've heard through he contractor grape vine that:
What Sam says is code now in most cities in NE Ohio.
The local building department (as mentioned) can give you the right answer.

Thanks Rich. The contractor stated that Streetsboro requires the footing to be 42" deep where most cites accept 38" deep so I assume he is familiar with the local code but I am going to make the call anyway.

[Allan Dozier]

Yes, best advice is check with your building standards department. When they were building the deck on my shop last month the 6X6 posts failed inspection. They had to go back and pour footings for each post 16" X 16" and 8" thick to meet code.

[Sam Murdoch]

Yes, best advice is check with your building standards department. When they were building the deck on my shop last month the 6X6 posts failed inspection. They had to go back and pour footings for each post 16" X 16" and 8" thick to meet code.

Somebody in that department has a relative in the concrete business . Was your shop deck BIG and off the ground 8+ feet? In a flood plain?
It's what it is but sure seems excessive.

[Brian Kent]

I am replacing my fence today. Treated posts in concrete 18" deep. All but the top 3-4" is entirely rotted away. They are only 7 years old in a very mild climate. I am using Simpson galvanized Standoff Post bases.

[John K Jordan]

I am replacing my fence today. Treated posts in concrete 18" deep. All but the top 3-4" is entirely rotted away. They are only 7 years old in a very mild climate. I am using Simpson galvanized Standoff Post bases.

Yikes. That would explain the wobblies!

Hey, are the Simpson bases strong enough to resist side loads on the fence? I was afraid they might bend and allow the fence to tilt, perhaps from high wind loads. I've never used them.

JKJ

[Brian Kent]

The ones I am using are through Home Depot: I add a 1/2" x 6" bolt through the bottom, with a washer and nut against the bottom. I use a couple of galvanized 1/2 bolts through the fence post, and there are holes for additional nails. I think they will be fine in the wind but I also don't live in hurricane or tornado country.

http://www.homedepot.com/p/Simpson-S...44AZ/100374846

[Sam Murdoch]

Not contributing to this discussion as I misunderstood the question.
Oh well...

[David Helm]

In my forty year building career I have built hundreds of decks; to my knowledge, all still standing. In my location, frost depth is only 14 inches. For a deck at the first floor, no roof, code calls for a footing that is 12 X 12 x 18 inches deep. I would never pour a sonotube without a wider footing beneath it. All the commenters talking about stand off brackets are right on. Even the old CCA treated lumber would rot when under ground. The lumber is called ground contact, not under ground. As several people have said, check with your local code department for specifics for your area.

[John K Jordan]

The ones I am using are through Home Depot: I add a 1/2" x 6" bolt through the bottom, with a washer and nut against the bottom. I use a couple of galvanized 1/2 bolts through the fence post, and there are holes for additional nails. I think they will be fine in the wind but I also don't live in hurricane or tornado country.

http://www.homedepot.com/p/Simpson-S...44AZ/100374846

The reason I asked about the side loads was because I always thought this type of post base was for structures where the posts were constrained from moving at the top like a deck, what Simpson calls "top-supported structures". Their web site states The PBS post base provides a connection between a post (or column) for decks, patio covers and other top-supported structures.

I found this about PBS on the Simpson web site and in their manual: Post bases do not provide adequate resistance to prevent members from rotating about the base and therefore are not recommended for non-top-supported installations (such as fences or unbraced carports).

http://embed.widencdn.net/pdf/plus/s...7-p098-099.pdf
https://www.strongtie.com/standoffpo...pbs_base/p/pbs

It just seemed a shame if the brackets failed after all that work.

In their E-Z line Simpson does offer what they call an E-Z Base advertised to attach 4x4 fence posts to concrete. But even then they have this disclaimer about side loads: Notwithstanding the terms of the Limited Warranty, Simpson Strong-Tie does not guarantee, represent or warrant that this product will perform under, or prevent or reduce damage caused by corrosion, any seismic, wind, atmospheric, or other load-producing event.

https://www.strongtie.com/fences_dec...nder.e-z-spike

I am not a structural engineer and am not trying to second guess your design. If there is any doubt, you might check with a fencing contractor or architect.

JKJ

[Marc Jeske]

CCA treating has proven to last for longer than many think.. IF.. and only IF, the sufficient or higher concentration per the use.

Allen in post #16 started to explain this.


Even though CCA .6 or as low as .4 is most commonly used at and IN ground, history shows .80 (harder to find.. NOT at Big Box stores).. fares many many more years.

The stuff used by even like Governmental agencies for long term saltwater exposure
( the overall most attacked due to "Marine Borers", etc) is if I recall 2.5 , 4- 5 x the typical homeowner stuff.


In the pole shop we are building this summer, we are providing the .80 posts.

Contractor uses .60.

Best to try to source from a local "industrial" type of lumberyard, or ask a local Treating company for dealers.


And it also goes back to what is being discussed above, as I mentioned also, any method where the post does not go down substantially below grade will be a weak link in the chain.

It's only logical.

So then, in many cases will involve additional bracing and hassles.


I am NOT debating longevity of concrete vs wood in ground.. I DO believe the longest lasting overall will be NO wood in or close to grade.

But that also assumes properly formulated.. AND placed concrete in decent conditions, to give that long life.

NOT just Yahooo's pouring dry bags.


It all though comes down to if one is in an inspected area, choices are limited.

Some info in link below- See the Table at bottom of page.

Marc

http://www.ccaresearch.org/about_cca.htm

[Marc Jeske]

For those interested in deeper info on this issue... Marc

http://www.americanpoleandtimber.com..._specguide.pdf

[Allan Dozier]

Somebody in that department has a relative in the concrete business . Was your shop deck BIG and off the ground 8+ feet? In a flood plain?
It's what it is but sure seems excessive.

You are probably on to something there Sam, good point. The deck is raised up above the basement, like a second floor deck. And it is also covered with a roof.

[Brian Kent]

Thank you for the info, John. They are all in the ground now. Glad this is not tornado country!