Concrete Forms

[mmjanrunner]

Hello All:

I'm new to this forum and have a question similar to the last one posted.

I will be building an attatched garage this spring. I have access to everthing needed accept the concrete forms for the frost walls.

The building is a simple rectangle. In New York I'm required to be at a depth of 48 ".

Onto the questions.

Is it necessary to attach the frost walls to the house foundation via pins??
There are no pins in place, hammer drilling would be needed. Building the footer forms is straight forward and the lumber could easily be reused somewhere during garage construction.

The problem is the frost wall forms. I have contemplated ICF forms, but it seems wasteful.

The other option is to construct the forms out of 1/2 osb(could use plywood). The osb would be braced by running 2x4 around the perimeter and one 8 footer down the middle. On the perimeter I would have a lip so one would overlap the next. the form would be attached to the footer via an inner and outer plate anchored to the footer via a hilti. The Forms would be screwed to the plate. The top of the forms and the sides be braced via 2x4 stock every 2 -3 feet (suggestions).

I checked around, form rental is not an option.

Snap ties are not an option. I would have to buy the bracing hardware.

The osb solution is ideal because the lumber could be reused after they are taken down. I'm told if treated with deck water sealer the forms will separate quite cleanly.


What do you folks think?

Thanks in Advance.

M

[Rich]

As far as the forming goes check this article on Concrete Stemwalls (http://www.construction-resource.com/concrete_stemwall.php) out.
The OSB idea should be just fine.. the only thing I can think bad is the concrete may get into the layers and delaminate it fairly quickly.. then again it may not :). The article above can use Gates twist ties - it's not as good but I've done many foundations with them. Also I would suggest not using Hilti pins to put down the form plate on top of the footers - if you get on the footing quick enough you can drive double head 16d's into it with no problem. And they are easily removed afterwards. I would also just nail the form to the plate with 8-10d nails. More than good enough.
As far as anchoring to the house - I probably would - but I don't think it's absolutely necessary to do so.

[mreynolds]

Rich,
I don't know if this would apply, but do you know anything about a shallow frost protected foundation? I am not sure where I read about it, basically they form stem walls either from block or poured concrete but used insulated sheathing so they don't have to dig down as far. :?

[Rich]

Yep.. I've actually got the white papers on it from NAHB. It's a really interesting method of design.

[mmjanrunner]

Hi guys:

Thanks for the heads up on the Shallow Frost Protected Foundation.
In my town anything attached to the house needs engineer stamped plans.

Do you think a local engineer would be aware of this method?

I went to the NAHB website and I would need plans for the unheated space.

How would you folks proceed?

Michael

[Rich]

I would find a green building engineer. They should be able to help you out with the specifics of that type of design.