I'm replacing a deck that the previous home owner had built improperly. So here are my questions:

Unlike fence posts, where I just dig a hole and pour in some quickcrete, what should I do different for posts that will support a load bearing outdoor deck ? If it makes a difference, my deck will be close to the ground, not second story, etc.

1. How deep for the post holes ? Climate is southeastern Virginia, not too cold in the winter regarding frost line to prevent heaving. But I don't know how deep that actually is for my climate.

2. How wide a hole for 4x4 pressure treated posts that will be filled with concrete ?

3. What material goes in the bottom of the hole below the cut end of the post ? Just dirt, some concrete, or something else ? I will be treating the tops and bottoms of the post cuts with copper preservative, which according to the salesmen will keep out termites under the ground and fungus/rot from the top.

4. Whatever else I forgot to ask because I don't know any better to ask.

Thanks guys.

You can use 6" diameter builders tubes in the ground, below frost line. Fill with quick creat and there are galvanised plates and brackets which anchor your posts atop, not down in the concrete. In will rot the poles away. A larger diameter builders tube would be more stable. Perhaps 12".

I've built a deck or two.

Your local code will have requirements for how deep to go, but typically a 4' 10" sonotube will do the job, with the tube about 6" above grade, with the post attached by a galvy shoe, itself attached via J bolt or other anchor to the concrete.

Code in most places is going to IRC, and at least here, 4x6 is the minimum.

How big is the deck, how high? What type of attachment to home?

I'd make the holes as narrow as possible. A post hole digger will give you 6x6?

We used to put flat rocks at the bottom, and never seemed to get to footer depth because of shale. The deck is still flat and level, decades later.

The other way is to dig, insert a tube, fill with concrete, and set a lag in the top of it for a receiving plate.

Pour footings and set the post on top. Or pour concrete pillars and lay your cross beams directly on the concrete.


Eta....

https://www.familyhandyman.com...eck-footing/view-all

Around here we need to pull a permit to build a deck. They tell you how deep to dig the holes and what size they need to be.

Do not put the posts in the concrete. Use a stancion to put the post on top of the concrete. They are anchored in the concrete and the post is then anchored to it.

Lay your decking boards correct side up. Many people don't think about the difference, but there is a right and wrong way to lay them. Lay them so that the "outside" of the tree is up. As in the cupping is facing down. Some boards are cut from heartwood, but you should avoid those if you can. Other boards will have distinct sides, and should be placed as I said. They will look more uniform and will last better if done that way.

quote:

Originally posted by arcwelder76:
I've built a deck or two.

Your local code will have requirements for how deep to go, but typically a 4' 10" sonotube will do the job, with the tube about 6" above grade, with the post attached by a galvy shoe, itself attached via J bolt or other anchor to the concrete.

Code in most places is going to IRC, and at least here, 4x6 is the minimum.

How big is the deck, how high? What type of attachment to home?

This sounds like what I have always seen, not a carpenter, but I have witnessed plenty of decks being built.

I didn't see a requirement for concrete piles/footers in the OP, so I'll offer this alternative. My apologies if it constitutes thread drift.

I just build a deck for my daughter's new house and we chose to use helical screw in piles. The local franchise is Goliath Tech..

In, piles located, installed and out in about an hour. Cost comparable with concrete, especially considering you can go from bare dirt to buildable piles in an hour or two.

I'd use them again.

quote:

Originally posted by PHPaul:
I didn't see a requirement for concrete piles/footers in the OP, so I'll offer this alternative. My apologies if it constitutes thread drift.

I just build a deck for my daughter's new house and we chose to use helical screw in piles. The local franchise is Goliath Tech..

In, piles located, installed and out in about an hour. Cost comparable with concrete, especially considering you can go from bare dirt to buildable piles in an hour or two.

I'd use them again.

Wouldn't the OP need to get a large block of earth to use these PHPaul ?

quote:

Originally posted by PHPaul:
I just build a deck for my daughter's new house and we chose to use helical screw in piles.

15 years ago I was on construction of a movie set, one of the M Knight S. movies. We build a 4-story "hotel" over a few months complete with steel frame, concrete floors, etc. The whole thing was built on 2" piles driven into the ground. Amazing project.

As far as building techniques go, screw-in piles sound great.

Consult your local building code, but....

You don't need sono tubes for a close to ground deck, imo. The concrete around a post is for shear lateral capacity and you will have basically no lateral forces in play if you're building within a foot or two of the ground. So quikcrete directly in the hole is what I would do. Frost depth in S. Virginia is 18-24" so I'd go the lesser of those two if it's very close to ground, higher if you're up 4 or 5 feet. I would dig my hole no more than a foot in diameter. Depending on your soil type... we have hard red clay here and I don't put anything in the hole when I build. (Just built a playground for my kids with 4x4 posts.) If the soils are richer and looser, then tamp as much as you can and maybe put 2" of pea gravel down.

Are you in hurricane country?

quote:

Originally posted by David Lee:
Wouldn't the OP need to get a large block of earth to use these PHPaul ?

??? I'm missing something here, not that that is particularly unusual.

Go to Golieth, click the menu, scroll down, click Our piles, scroll down through the pics, most have a rectangle block of earth beneath them.

quote:

Originally posted by David Lee:
Go to Golieth, click the menu, scroll down, click Our piles, scroll down through the pics, most have a rectangle block of earth beneath them.

Ah. I'm going to demand a refund, I didn't get my block of dirt!

some helpful stuff here
https://www.google.com/#q=ask+...construction&tbm=vid

quote:

Originally posted by arcwelder76:
I've built a deck or two.

Your local code will have requirements for how deep to go, but typically a 4' 10" sonotube will do the job, with the tube about 6" above grade, with the post attached by a galvy shoe, itself attached via J bolt or other anchor to the concrete.

Code in most places is going to IRC, and at least here, 4x6 is the minimum.

How big is the deck, how high? What type of attachment to home?

I would go with Arc's recommendation. The only thing I would add is to "Crown" the concrete so the water runs off.

I am the only person here that doesn't recommend Sonotubes since I have seen many failures withe them.

I suggest holes dug.to the proper depth. The dug out holes 16" round at top and 20" at the bottom. Fill hole with concrete. Install 8x8 sash into wet concrete and fill the middle with concrete. Install 12" anchor bolt in the middle leaving 3/4 of the threads exposed for the post bracket.

You will use more concrete this way by its more solid and looks better than sonotubes sticking out of the ground.

quote:

Originally posted by Captain Morgan:
I am the only person here that doesn't recommend Sonotubes since I have seen many failures withe them.

I suggest holes dug.to the proper depth. The dug out holes 16" round at top and 20" at the bottom. Fill hole with concrete. Install 8x8 sash into wet concrete and fill the middle with concrete. Install 12" anchor bolt in the middle leaving 3/4 of the threads exposed for the post bracket.

You will use more concrete this way by its more solid and looks better than sonotubes sticking out of the ground.

The 8x8 sash you speak of...is that a 8x8 concrete block? and then you put it into the poured concrete?

Why install a concrete block into a blob of concrete you just poured?