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FramingPro

· Forming and Framing
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Discussion starter · #1 ·
I may be doing a fence and i am doing the deck this summer so this question is critical. Do you need sono tubes or could you just put concrete in a hole. My worry is that if i make the hole tapered the frost could grab the top and ruin all my work. Also the frost line here is 48" and sonotubes come in 8' lengths, i fell like i need to extend the concrete above the ground a few inches and this would leave me with a unusable 40+" length. How do you guys do it:whistling
 
Dig your footing holes then set up tubes about 6 in below grade and as far above grade as you want. I dont have any pics of this but its really easy. Nail the tubes to stakes running horizontaly to set grade then brace the top plumb. Pour the footing stiff and vibrate the tube to get it pretty. 12 in peices of tube put you 6 in +/- above grade. Ive done this many times for light post bases.
 
Discussion starter · #3 ·
Dig your footing holes then set up tubes about 6 in below grade and as far above grade as you want. I dont have any pics of this but its really easy. Nail the tubes to stakes running horizontaly to set grade then brace the top plumb. Pour the footing stiff and vibrate the tube to get it pretty. 12 in peices of tube put you 6 in +/- above grade. Ive done this many times for light post bases.
just join them is what you are saying?
 
When building a deck I usually use bigfoot footing forms, with sonotube for the piers. I usually put 3 bars of #4 bar bent at an "L" and tied together in the center of the column. You can either set the post base in the pier after you pour it, use a "j" bolt and affix the post base to the pier that way. Make sure that you size your footings as well

http://www.bigfootsystems.com/
 
Nick, when I do fences I dig 4' deep, install the sono tube to just below grade.

I make sure when I pour the concrete to slope the top so water will not sit on the concrete.

You need to put the sono tube all the way down, otherwise the frost will grab the concrete. The tube leaves nothing for the frost to grab.

I also put in about 6" of washed stone in the bottom of the hole to prevent water from rotting the bottom of the post.
 
Discussion starter · #8 ·
Nick, when I do fences I dig 4' deep, install the sono tube to just below grade.

I make sure when I pour the concrete to slope the top so water will not sit on the concrete.

You need to put the sono tube all the way down, otherwise the frost will grab the concrete. The tube leaves nothing for the frost to grab.

I also put in about 6" of washed stone in the bottom of the hole to prevent water from rotting the bottom of the post.
i was thinking of putting in a bit of concrete then the post.
 
Nick, when I do fences I dig 4' deep, install the sono tube to just below grade.

I make sure when I pour the concrete to slope the top so water will not sit on the concrete.

You need to put the sono tube all the way down, otherwise the frost will grab the concrete. The tube leaves nothing for the frost to grab.

I also put in about 6" of washed stone in the bottom of the hole to prevent water from rotting the bottom of the post.

Why would the tube need to go all the way down? Do you wrap your foundation in cardboard? Your supposed to strip the tube off. How long do you think cardboard last under ground.

If your footing size has to be quite a bit larger than the bearing point you would pour footing below frost and tube up to above grade.

You put rock below the concrete tube? I was talking about piers for decks. I would never spend the time or money on sono tube to be buried for a fence post. The concrete 4 ft down will grab the ground below frost making what happens in the first three ft irrelevant.
 
I may be doing a fence and i am doing the deck this summer so this question is critical.
Nick, if it's critical you need to ask two different questions. There's a world of difference between what you need for a load-bearing deck post and one that only needs to hold a fence in place. :thumbsup:
 
Fence Posts - I never use sonotubes - waste of time and money. Dig your holes 42"-48" down, put a couple inches of clear stone in the bottom, put the post in, level and then fill the hole with concrete until you are 6"-8" below grade, backfill with dirt, check level on the post, adjust if necessary and then move on to the next post.

Deck Piers - always, always, always use sonotubes. In the Toronto area, footings have to be 48" below grade and sonotubes have to extend 6" above grade.
 
Just to add some pics for you Pro. These are for decks.

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Like mentioned above here the footing has to be no less than 42" deep. And the top of he concrete has to be minimum 4" above grade to meet code. There also has to me some kind of post base so the wood post doesn't rest directly on the concrete.

Cole
 
Hey guys, he's asking about FENCE posts. Not deck posts.

Nick, Ubinhad is correct though, you only need the sono tube to go below frost level.

Maybe someone knows what that is? It's probably around two feet. But seeing as code is four feet, I just run the tubes all the way down. In the GTA tubes only come in 8' now. I just cut them in half to start, then fine tune them for each hole.

Yes code wants 6" above grade - for a deck. Fences don't even require sono tubes. This is done by thous who do it just so the frozen ground will not grab the concrete and heave it.

Nick there are several different ways you can do this, I was just saying how I do it. There is no hard and fast rule about it as it's not required by code.
 
If your pouring a tube in a hole then backfilling a four ft hole whats the benifit of pouring a post in concrete? Your just making a bigger post in a bigger hole not locking it into the earth.

I don't want it locked into the earth. The frozen ground will heave it in the spring. With the sono tube the ground slides up and down against the tube.
 
For fences, sonotubes are not required, but putting them in is a good construction practice and insurance against frost heave.

On a side note, when we install structural caissons ranging from 6' to 16' deep here in sarnia, the engineered drawings show tubes into the ground 3' deep only for frost protection.

I haven't built a fence in a while, but if I did I would cut my tubes at 40", then build a jig that would hang them all at about 2" above grade, that way you're not custom cutting every tube, you get frost protection and the finished product looks consistent.

If you're bidding for a job, be clear as to what the owner wants, since adding the time and money for tubes will put you over the top for sure.
 
Just to add some pics for you Pro. These are for decks.

Image


Image


Like mentioned above here the footing has to be no less than 42" deep. And the top of he concrete has to be minimum 4" above grade to meet code. There also has to me some kind of post base so the wood post doesn't rest directly on the concrete.

Cole
Hey Cole,

I love the tube base method, it's a time saver for sure.

Have you ever put rebar in these things? I'd love to use them some time but all our plans always call for bar. Too much fuss to figure out at this point. Any suggestions?
 
I don't want it locked into the earth. The frozen ground will heave it in the spring. With the sono tube the ground slides up and down against the tube.
Wow I didnt realize you guys have that much frost heave. Ive put in hundreds upon hundred of fence post for miles of fence and we never had a problem with any of them heaving. They where mostly rail ties or 6 in rounds 36 or so down, just poured in mud with some 3/4 minus on the bottom. I have always looked at it as a house foundation that as lond as the foot of the pad is below frost level it shouldnt move.

So there the frost grabs the sides and lifts the footing? That must be super tough on everything.
 
ditch the sono tubes

redifooting.com

check out redi-footings--I've used them a few times & love them. It uses pvc pipe. They sell them locally here but you can order them online if they don't sell them near you. No concrete to mix & each footing is rated for 8,000 lbs.
 
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