Building a deck...concrete posts into ground or set conrete footers?

[blurredvision]

I have a deck build coming up in the next couple of weeks, and I've seen just as many sites suggest setting posts into the ground with concrete as sites that suggest pouring concrete footers and attaching my posts with brackets.

Without laying any plans on paper yet, I'm anticipating upwards of 20 posts, either 4x4 or 4x6. At the tallest end of the deck, it will be around 50"-55" off ground level. At the smallest end, around 24"-36". Entire size of the deck will probably be around 10'x20', but that's still up in the air.

So which is it ATOT? I'm more comfortable with setting posts 24"-30" into the ground with concrete around them, but I want to make this deck whichever way is best to do it.

 

[iGas]

both method works, and you don't need to set the post so deep unless you are worries about hurricane & such.

 

[wedi42]

set the posts on brackets. it keeps them dry.

 

[iGas]

Originally posted by: wedi42
set the posts on brackets. it keeps them dry.

That work well too, and the posts would last longer than the deck.

 

[meltdown75]

i dug 22 holes with a hand auger, set my 4x4s, and filled each hole with concrete. 4 feet deep

i'm not sure which method is best but i built my deck in 2003 and it is holding up well! good luck

 

[Goosemaster]

posts: gravel at the bottom for a few inches, set the post in place with concrete -very easy to do.

pier: a solid subterrainian concrete pier will allow for universal post compatibility IF you need it if you change your mind since you can use brackets to customize it. you also don't have to worry about deck material health.

 

[Kelemvor]

be sure to go below the frost line if you live somewhere you have to deal with that.

Also call your city hall as many places have codes about that and you can be made to rip out the deck if you do it wrong.

 

[CPA]

Originally posted by: meltdown75
i dug 22 holes with a hand auger, set my 4x4s, and filled each hole with concrete. 4 feet deep

i'm not sure which method is best but i built my deck in 2003 and it is holding up well! good luck

I did about 30, set post bracket on concrete, then nailed joists to bracket. Not sure which is best either, but I will say in hindsight there is a section of my deck where I wish I had set 8' 4x4s for the railings. I did the railings an alternative way and I haven't been happy with them.

 

[blurredvision]

Originally posted by: iGas
you don't need to set the post so deep unless you are worries about hurricane & such.

Originally posted by: Goosemaster
posts: gravel at the bottom for a few inches, set the post in place with concrete -very easy to do.

Gravel at the bottom for drainage is why I'm estimating 24"-30" hole depth.

 

[MikeyIs4Dcats]

aside from any local code requirements, it depends on if you live in a cold climate. if you live somewhere that it freezes, you need footings extending below the frost line otherwise the deck will heave in the winter.

 

[meltdown75]

Originally posted by: CPA

Originally posted by: meltdown75
i dug 22 holes with a hand auger, set my 4x4s, and filled each hole with concrete. 4 feet deep

i'm not sure which method is best but i built my deck in 2003 and it is holding up well! good luck

I did about 30, set post bracket on concrete, then nailed joists to bracket. Not sure which is best either, but I will say in hindsight there is a section of my deck where I wish I had set 8' 4x4s for the railings. I did the railings an alternative way and I haven't been happy with them.

i'm strongly considering modifying the lower part of my deck. there's just too many spindles, i'm not a fan of how it looks anymore. not to mention my veggie garden is to the left of the lower level of my deck, which is enclosed by 4' spindles. the stairs to my yard are to the right.. i don't really like walking all the way around my deck to water my garden or pick tomatoes :/

in hindsight it was a nice deck, but way too big and ended up not being practical given the current location of my garden.

 

[Greenman]

The answer is; it depends.
If you happen to live where someone cares, setting the posts in concrete and attaching it to your house creates an earth wood contact situation. This is often of no importance what so ever, but if you sell and there is a termite report, it will be called a section one item and could cost you fair pile of nickles to correct. If you do plant the posts in concrete, be sure to use pressure treated material and hangers rated for PT contact. The PT will eat zinc plated hangers in a year or so, you don't want that.

 

[Red Squirrel]

Use pressure treated lumber as well or the moisture will just seep through over time (even through the cement).

 

[blurredvision]

Forgot to mention that this deck is free-standing and will not be attached to the house. I live in central KY, so it does freeze, but I don't think the frost line is ever more than a few inches down.

 

[arkcom]

You really do not need that many posts for a 10x20 deck.

 

[Squisher]

How to best set the posts depends on your location and the type of soil.

I notice your profile says Kentucky, so not much frost heaving.

I'd ask some locals.

 

[vonmises]

Our deck is was just done with footings, 4 feet down with a bracket bolted to the concrete and nailed to the post. Our supports are only 2 feet though. The frame was done 15 years ago and is still holding strong. We just added a new section and redid the flooring/railings. Edit: I typed before that last post.

 

[MikeyIs4Dcats]

Originally posted by: peritusONE
Forgot to mention that this deck is free-standing and will not be attached to the house. I live in central KY, so it does freeze, but I don't think the frost line is ever more than a few inches down.

for comparison, the rost line in Kansas is 36 inches. In Minnesota it can be over 5 feet.


for a 10'x20' deck with posts along the perimeter, using 2x8 joists you should do 3 rows of posts each way.

 

[Gothgar]

if you set in concrete just make sure and use pressure treated wood

 

[waffleironhead]

Originally posted by: iGas

both method works, and you don't need to set the post so deep unless you are worries about hurricane & such.

or frost heaves

 

[Sea Moose]

Originally posted by: iGas

Originally posted by: wedi42
set the posts on brackets. it keeps them dry.

That work well too, and the posts would last longer than the deck.

this ia what we did at my mates house, his reaoning was that termites dont eat the steel. But do eat the underground timber

 

[skyking]

pier blocks with brackets will work fine in your situation.

 

[alkemyst]

Originally posted by: Goosemaster
posts: gravel at the bottom for a few inches, set the post in place with concrete -very easy to do.

pier: a solid subterrainian concrete pier will allow for universal post compatibility IF you need it if you change your mind since you can use brackets to customize it. you also don't have to worry about deck material health.

Being that the OP is talking concrete posts this would work.

Many make the mistake of setting wood posts in the stuff and this is not only against code (at least around here), but causes many problems.

 

[paperfist]

Originally posted by: alkemyst

Originally posted by: Goosemaster
posts: gravel at the bottom for a few inches, set the post in place with concrete -very easy to do.

pier: a solid subterrainian concrete pier will allow for universal post compatibility IF you need it if you change your mind since you can use brackets to customize it. you also don't have to worry about deck material health.

Being that the OP is talking concrete posts this would work.

Many make the mistake of setting wood posts in the stuff and this is not only against code (at least around here), but causes many problems.

What problems? The wood is going to rot either way.

The argument is that once it's set in the concrete there's not much air getting in to move the rot process ahead. Plus with the gravel at the base there's drainage away from the soil.

The concrete will rot against the wood because of dissimilar materials? The same can be said with the brackets.

I've used both processes. I would never use the bracket process again. When you set the bracket in concrete you get what 2 - 3" of the anchor going into the concrete? You have to be sure the concrete is completely surrounding the anchor part of the bracket. The brackets typically don't end up being too sturdy and can become loose.

If it were me I'd go overkill and use 6x6 and go below the frost line even if it's not there. It'll be sturdy with 3'+ of concrete around your post and surrounded by earth. It's going to take eons to rot with a 6" post of wood.

 

[skyking]

Originally posted by: Greenman
The answer is; it depends.
If you happen to live where someone cares, setting the posts in concrete and attaching it to your house creates an earth wood contact situation. This is often of no importance what so ever, but if you sell and there is a termite report, it will be called a section one item and could cost you fair pile of nickles to correct. If you do plant the posts in concrete, be sure to use pressure treated material and hangers rated for PT contact. The PT will eat zinc plated hangers in a year or so, you don't want that.

I agree, and I've seen so many rotted off posts set in concrete. people underestimate how fast that goes.
I used pier blocks with adjustable saddles on the interior of my porch, and poured saddles into a footing pads around the exterior.
Other than the skirting I maintained 6" between earth and wood. The skirting wood contacts 8x16 pavers set with a slope in gravel.

EDIT:
Link to elevated post base.
That keeps the wood away from the dirt and eliminates wet rot.
I set up a piece of lumber and screw the base to it to keep them in line and approximately on grade.
There is no need to be exact on the grade however. just top the posts using a water level, laser, or a long level.
pour each base in an 8" deep by 2' by 2' pad and it will be as strong as you need.