I wanted to ask what everone thinks about putting the deck post in the ground with concrete poured around it. Here the bottem of the hole has to be two feet. I drill a hole crossways and put a piece of rebar in and put the uncut end down and then pour mixed concrete in. What do you think and what do other do around the country?
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Here in the Winter Wonderland (Michigan) we have to go down 42", so we pour a pier and set the post about an inch above grade, on a bracket. This keeps the post dry and allows for small adjustments in alignment. With a power auger and sonatube forms, it's fast and pretty simple.
Simpson makes a galvanized steel post base that you put in the concrete. Then you go up from there with the post, which is now held a couple inches above the concrete, so it stays dry. Look at:
http://www.strongtie.com
-- J.S.
What do you gain by embedding the post in the concrete?
Even some in the east use this method. (I think I remember Mike Smith mentioning it.)
My answer is, it depends. For the most part, when the force on the post is generally in the downward direction (such as a deck) I use the Simpson standoff. If there are potential forces other than down (such as those experienced by a gate post or a privacy screen post) I might go ahead and sink it into the concrete to provide a sturdier foundation to prevent possible post deflection. When doing so, the sonotube is above grade, and I try to smooth and sculpt the concrete to shed water.
To be honest, I wish I could do it more often, or at least convince myself that it's a good way to go for all applications, but I've had to replace too many that were sunk in concrete that have rotted at the interface, probably due to poor watershed detail. Even PT SYP.
Now I wait for Mike S. : )
nick .. when i started we used the concrete pier with the post base... no lateral resistance..but we didn't have PT lumber to build with either
what we do now is dig our hole to 42" below finish grade... pour a one bag mix of QuickCrete and tamp the top smooth... then we set our post on the footing and backfill.. if it's a deck we use .40 treated..
if it's a structure like a pole building, we use .60 treated.... some of my posts set in the wet Rhode Island glit are 25 years old.. and thye fare just as well as the ones set on a concrete post baseMike Smith Rhode Island : Design / Build / Repair / Restore
Mike,
Do you backfill witht the excavated soil of gravel? How well does your soil drain?
Jon Blakemore
jon .. i backfill with gravel or peastone at the bottom and finish with the soil we took out.. our soil is glit ( glue & sh*t).. it drains better than pure clay...Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike, who you trying to kid? You didn't dig those holes. Your employees did, you just took the pictures...............:-)
I like the way you wrapped the posts in woodland brown Trex.
Around here we use Sono tubes and Simpson brackets or a 2'x2'x8" deep hole with one bag of pre-mix then a pier block, then another bag of pre-mix around that.
Every area is different."Rather be a hammer than a nail"
Bob
That was quick, you must have heard your name thru the cable/phone line. Nice deck, btw.
I'm not saying it's wrong to bury the post, that would be ignorant, I'm just saying that I don't do it that way. I think burying the post acutally looks better than having it sit on a stand off, and I also think the post is better supported and can withstand more lateral deflection. But I also think that the post will last longer if it is not in direct contact with the pier or ground.
If you've had good success with it and can sell it to the client, then that's your decision. I'm not thrilled with stand-offs, but I've also seen the results of not using them, probably as a result of poor construction initially.
A good thread; the topic is always good for some debate.
I never met a tool I didn't like!
I've included a pic of the style of decks I usally build here in Ks. They've all been low to the ground and I've yet to attach to the house. I build a beam 2 ft away from the house with joist on top. The outer post go into the ground. The rebar prevents vertical movement and with the post going all the way down prevents lateral movement. Since the post are usally green when I put them in, as they dry, rain will seep down the side and drain on into the soil. If you put it into the middle of the concrete you create a bowl that just holds the water. I think the one thing I might do is put tar on the bottem of the post. What do you think of my reasoning?
wall... Ks huh ?... spent 4 years in OK..
here's another one.. this has the rail posts independent of the support posts..
oh.. and a bob.. i do too dig those post holes... if there's 10 of 'em i dig one and say.. ok.. make the next 9 just like that only better.....Mike Smith Rhode Island : Design / Build / Repair / Restore
If you have soil that maintains a decent shape to the hole, what advantage is there to using Sonotubes or similar? Is it just for appearance, to save a little concrete, or some other reason?
I had thought of using those newer round plastic footing forms that flare out at the bottom but checked the price and decided that they were a little too pricey. It will be cheaper to just pour the concrete all the way up to the top as we only require 24" frost depth here in OR. Anybody use them. If so, what are the thoughts?
The prevailing conventional wisdom wrt Sonotubes is that their smooth sides will not allow a purchase for frozen ground to grab and heave up when it freezes. And they're nice to elevate the concrete above the ground.
Bigfoot, the inverted funnel shape doohickey, allows you to pour the footing and pier all at once. Before the Bigfoot, we would often pour concrete into the Sonotube tube, lift it to allow the crete to flow out the bottom, thus generating a footing. That may or may not fly elsewhere. I've used Bigfoot before and it worked well, and I'll probably use them again this spring when I have to replace a beam and piers under a sunroom. It saves on the time and labor of a separate footing, should you need it.
I never met a tool I didn't like!
If I need to put a post into the ground (lateral resistance), I set it in concrete, sloped away from the post, then, wrap that point with copper .. stops the rot.
I've thought about doing something similar, routing a groove around the circumferance of the post, about 6" above where it goes into the concrete, then flash the post with lead or copper, one edge in the groove, the bottom below the surface of concrete. Got the idea from the boat ramp at the seaport, they protect the tops of some piers doing it that way. (The groove thing. They insert lead in the groove and cover the top of the pier.)
You ever have problems with water getting between the post and copper? It's not a big gap, but water is sneaky that way.
I never met a tool I didn't like!
handsome is as handsome does , joe... nice looking workMike Smith Rhode Island : Design / Build / Repair / Restore
it's OK if water gets in there because it just runs out the bottom. The water actually then carries a little copper with it, washing down over the post at its' most vulnerable spot .. where it enteres the concrete. Stops ALL the rot.
To All, here in Arizona, well at least around my parts, when the Home Inspector does the walk about, on a home for sale, there cannot be any wood to earth contact, on anything touching the Home, Period. Mortgage Co. won't loan. Both City and County require minimum 6" clearance from earth to wood, ie concrete post base standing proud 6". Though, I have set many of post in ground, never on anything touching a residence, well almost never. Jim J
I'll ask the stupid question, Why? Seems to me that the SW part of the country is the dryest, so moisture induced rot would be less likely to occur down that way. (Mental pictures of dried up ghost towns come to mind.) Or is it just a regional thing?
Forgive my ignorance, just curious...
I never met a tool I didn't like!
Termites.
That's my guess.
Jon Blakemore
Ahhh, those lovable little bugs, forgot all about them. Treated lumber doesn't bother them out that way?
I never met a tool I didn't like!
Jon B, got it right,, Termites. I suppose the thinking is, keep the food source (wood), just out of site of the little buggers. I had forgot to mention the Termite thing in my first post,, whoops. You All Be Safe out there,, Jim J
I like to drop 6" or so of gravel in the hole, put the post in, then add another 6" or so of gravel before placing any concrete. The theory is that any water that gets to the bottom (especially between concrete and post) will not sit there and rot out the post. The neighbor's fence with that method has been there since 1955, still straight and solid.
What does the concrete do for you that well tamped backfill wouldn't do? Is it just the time it takes to tamp the backfill properly?
Dunc, you're right - a good tamping will work just as well. Maybe I'm just lazy - my last job was 8'deep retaining wall posts - concrete sure was easier!
Thanks, that's an excellent solution. I'll file it in my memory and try it next time....
-- J.S.
one thing about not using a sonotube form is that it is easier for frost to grab a rough shaped concrete pier and heave it..
sinc e our footing is completely below the frost line, there is nothing to grab
Mike Smith Rhode Island : Design / Build / Repair / Restore
I'll tell you one thing they do, they keep the hole from collapsing in. This is a bit of an embarrasing story but we were behind schedule on a project so we dug the holes into the dark. It began to rain so we quit and hastily got a huge sturdy plastic tarp over the holes so rainwater wouldn't get in. Stupid didn't account for the fact that it would rain so hard that the ground water would just rise up from the surrounding areas and fill the holes. In the morning, we lifted the tarp to find 8 collapsed holes. Half of which had drowned mice in them! If we weren't behind the day before, we sure were now. If I had thought to drop the tubes in immediately after digging the holes we would have just had to pump out the water.
the ground water would just rise up from the surrounding areas and fill the holes.
Pretty high water table. Got a lake nearby?
I never met a tool I didn't like!
Around here (Toronto, Ontario), it's pretty common to auger a hole and use sonotube, but with no footing (auger diameter = sonotube diameter). I've always thought this pretty risky. It's certainly easier than digging a hole the diameter of the footing (especially since no augers around here that wide), or somehow widening the hole only at the depth of the footing, but...
So is everyone doing a footing? And how are you digging it?
Regards,
Tim Ruttan
BIG one. Motor boats, wave-runners, water-skier type lake.
That's what I like about you Mike, you know how to delegate. I do one or two myself but hey! Who's gonna take the pictures?......................"Rather be a hammer than a nail"
Bob
Why are those windows set proud of the wall like that ?
Posting at Breaktime should not be a full contact sport.
quittintime
> If there are potential forces other than down (such as those experienced by a gate post or a privacy screen post) I might go ahead and sink it into the concrete
In that case, how about sinking galvanized steel pipe into the concrete, and box it with wood for appearance? Here, rot and termites seem to act faster than rust.
-- J.S.