How do you set forms for a single pour raised foundation?

[mtnbkr777]

We're doing a room addition on a raised foundation house and we're trying to figure out how to set the forms for a single pour. We've seen tons of info on the internet on how to pour a footing first and then rest the forms on the poured footing to pour the stem wall, however, we need to pour the footing and stemwall in one pour. We had a foundation contractor come out and give us an estimate on doing the forms for us and he was going to do a single pour system. We asked him about pouring the footing separately from the stem wall and he said "why the heck would you want to do that?" So then we called the building inspector to ask him about pouring the footing separately and he said "why the heck would you want to do that?" so we know we need to do this all in one go using the trenched out earth as the form for the footing and then I guess suspending the stem wall forms over the trench somehow. Any help on how you do this would be appreciated!

[roger g]

Since I have moved to British Columbia I constantly see these "one pour" foundations. I had never seen it before in my life. In my mind it is a real mickey mouse way of doing it but the locals really believe that it is the ONLY way to do it. In fact they never heard of pouring the footing first. Anyways, they seem to plonk the footing forms onto the ground without leveling them at all. The cross pieces of wood which keep the footing forms apart are used to stand the foundation walls on the footing forms. I assume they must frame around the cross pieces to stop the concrete from running out the side. Because the foundation wall forms done't seem to be sitting on anything too secure they used lots of bracings to keep the forms in place. I guess they must use a specific type of concrete slump factor otherwise the concrete pouring in from the top would bubble right out of the open footing forms. When the forms are removed the cross pieces of wood which held the footing forms apart and to support the foundation forms are embedded in the concrete and they stay there. Some guys tar the hell out of them but it still looks all wrong to me.
As I said at the first, the footings are not level but the finished top of the foundation wall is level. Strange to me but that's what they do..........here.


roger

[CurtisS]

When the forms are removed the cross pieces of wood which held the footing forms apart and to support the foundation forms are embedded in the concrete and they stay there. Some guys tar the hell out of them but it still looks all wrong to me.


roger

I saw it done this way and it made me decide to do the footings and stem walls separately for my garage. I am glad I did. It was easy but I suppose it took longer. I guess I am just anal... :)

[mtnbkr777]

I know, it's odd that it's done this way but the foundation of the original house which was poured in the 1050's was done the very same way.

Our concept is to basically have outriggers come out from the forms which will be sitting on the ground tied to stakes and then have bracing going from the top of the forms down to stakes as well.

We have not seen any foundation where wood ties are left embedded in the concrete so we think suspending the forms over the trench must be how it's done.

Does this sound like the right way to go?

[roger g]

Well, if you can figure a way of doing it I sure would like to hear it. I'm sure there is a way. Remember of course the weight of the cocrete inside that foundation wall, even thjough it is wet, stillexerts a lot of pressure straight down.
Years ago I worked as a draftman at EFCO ( look it up on the internet) and they make steel forms for concrete work. They could make any type of form that you want though when I was there all the forms were placed on already formed and set footings.


roger

[mtnbkr777]

I happened to be driving by a construction site last night and normally wouldn't have stopped since it's for a commercial building (usually all flat work) but I happened to notice a section of forms which is for some sort of raised foundation. Not sure why they're doing it but I didn't care. I got to see raised foundation forms set up for a one pour!!!! Wonderful!

Here's the interesting thing. There are no forms whatsoever for the footing. Just the trench alone defines the footing. Beyond that. The vertical stakes holding the forms in place are driven straight into the earth at the bottom of the trench such that once the concrete is poured, these stakes will be embedded in the concrete which makes up the footing. That's a little puzzling. My hope is to drive by after they pour but before they backfill around the new concrete to see how they handle these stakes. Is it possible they will just snap them off and leave the remaining section in the concrete?

[HarmsWay]

I saw an example of this one-pour style last night that had been poured earlier in the day. I took lots of pictures. As Roger says this is the way it's done here. I hope this one was not typical in terms of workmanship though. I'm a complete noobie in concrete but I spent an hour going through the BC building code and even I could see a few examples of code violations.

Bob

Since I have moved to British Columbia I constantly see these "one pour" foundations. I had never seen it before in my life. In my mind it is a real mickey mouse way of doing it but the locals really believe that it is the ONLY way to do it. In fact they never heard of pouring the footing first. Anyways, they seem to plonk the footing forms onto the ground without leveling them at all. The cross pieces of wood which keep the footing forms apart are used to stand the foundation walls on the footing forms. I assume they must frame around the cross pieces to stop the concrete from running out the side. Because the foundation wall forms done't seem to be sitting on anything too secure they used lots of bracings to keep the forms in place. I guess they must use a specific type of concrete slump factor otherwise the concrete pouring in from the top would bubble right out of the open footing forms. When the forms are removed the cross pieces of wood which held the footing forms apart and to support the foundation forms are embedded in the concrete and they stay there. Some guys tar the hell out of them but it still looks all wrong to me.
As I said at the first, the footings are not level but the finished top of the foundation wall is level. Strange to me but that's what they do..........here.


roger