How to form & place stem wall with slab ledge

[tjansson]

I'm building a small 10x10 addition to my house. It will likely have 60" frost walls and a concrete slab for the finished floor. I want to insulate the slab with foam as pictured which requires this 4"x6" curb on the frost wall. What's the best way to form and place this? Can a pump hose get inside a 4" opening to fill the form?

 

[Michigan Mike]

The concrete will flow through there. You will need a concrete ********. That will make the concrete more liquid and will also make it fill the bottom where you can't see how well the concrete is filling. I would order concrete that is a mix that is designed for pumping as the aggregate is smaller. You should probably make a funnel of some type for the pour.

 

[Michigan Mike]

After rereading your post I see that you are using a concrete pump. You need to talk to whoever is furnishing the pump they should have the tools and adapters to do the job.

 

[tjansson]

After rereading your post I see that you are using a concrete pump. You need to talk to whoever is furnishing the pump they should have the tools and adapters to do the job

Thanks for the response, Mike. I am not certain I will use a pump, but I was figuring it would be the easiest way and I've got an off camber approach to the site which I'm not sure a concrete truck can handle. Tractor bucket is an option too, but I was figuring it would require an elaborate funnel to get it into the form.

 

[duneslider]

Cement truck drivers just don't seem to be what they used to, now days it just seems best to go the pumping route. The tractor bucket seems like a lot of extra work. I think last year I was paying about 900 for a pump truck to come out. The guys with the pump trailers are less.

 

[Michigan Mike]

Have you thought about doing a concrete block wall? If you have a difficult to access site it might be easier to lay block than to get concrete and forms there. You will still have to pour a footing.

 

[billconner]

Curious about the detail. Generally does not comply with the IRC.

R602.3.4 Bottom (sole) plate.
Studs shall have full bearing on a nominal 2-by (51 mm) or larger plate or sill having a width not less than to the width of the studs.

Or so building officials tell me.

 

[tjansson]

R602.3.4 seems to refer to the studs having full bearing on the plate, not the plate having full bearing on the foundation. The detail is on Green Building Advisor and that picture I posted is from Joe Lstiburek: https://www.buildingscience.com/doc...sights-newsletters/bsi-118-concrete-solutions

This wall will be 2x6 so it will have 4" of bearing on the foundation, more the a 2x4 wall. More over, I don't have building inspectors so I am not subject to their interpretation of code.

 

[csp]

R602.3.4 seems to refer to the studs having full bearing on the plate, not the plate having full bearing on the foundation.

Exactly, it's the same configuration that many homes built on foundations poured with ICFs have. There's foam on the inside of the stem wall and on the outside.

 

[duneslider]

R602.3.4 seems to refer to the studs having full bearing on the plate, not the plate having full bearing on the foundation. The detail is on Green Building Advisor and that picture I posted is from Joe Lstiburek: https://www.buildingscience.com/doc...sights-newsletters/bsi-118-concrete-solutions

This wall will be 2x6 so it will have 4" of bearing on the foundation, more the a 2x4 wall. More over, I don't have building inspectors so I am not subject to their interpretation of code.

I have done a similar thing before and in my case the engineer just had to sign off. We had to do it for a different reason but the wall only needed to be 2x4 construction and we had to frame it 2x6 so it had over hang.

 

[billconner]

The ICF with a core smaller than wall is specifically permitted by the IRC subject to the ICFs manufacturer. It shows up in the Evaluation Reports and permits a 4" concrete wall above grade. An architect or engineer using accepted design can also design a 4" or possibly thinner wall. Otherwise by the prescriptive requirements of the IRC, these concrete walls have to be 6" minimum. Of course, if you are not required to build to code, you can do what you want.

 

[larry4406]

Styrofoam used all the time in concrete forms to create brick ledges and slab ledges.

I have done many where the foam is precut and at the ready but not yet inserted in the forms. As the forms are filled with concrete and rising, then they insert the foam for the ledge and continue filling the last of the stem wall.