Concrete slab question General Building and Construction Discuss Concrete slab question in the General forums; This morning I nailed in a few support braces for the plywood form. I think this is plenty support to ...

[fxpose]

This morning I nailed in a few support braces for the plywood form. I think this is plenty support to handle the weight of the concrete pour. I will also prop a couple of 2x4's under it.
Tomorrow, I plan on laying down some plywood, form rebars on top, erect perimeter forms, and pour the slab.

I have one question though: Should the center block column tie directly in with the slab or should the slab simply rest on the column and be independent of one another in case of settling? I could cut the column rebars and cover the top of the column with a piece of plastic sheeting before pouring the slab if they were to be independent.

[Neil2]

What does this centre column do ?

In any case, I would isolate it from the triangular slab. Connecting it structurally to the slab will induce all kinds of stresses and it will likely produce cracks.

Don't forget to allow for drainage of the "void" under the slab.

[fxpose]

Originally Posted by Neil2

What does this centre column do ?

That's a good question.
Having never done this type of construction before I thought the center column would give additional support but figuring the slab will be supported by sitting on top of the foundation walls on all three sides, why would I need it, considering the small area involved? There will be plenty of rebars also, so on second thought perhaps there was no need for this center column to begin with.
I'll probably just remove the top three blocks of the column as those cores are not filled yet and cut the rebars. I'll just add an additional wood bracing across the middle there...

[ThisOldGarageNJ]

fx,
after looking at the pic again,, that is not a tremendous span.. in my opinion you could surely leave it out.. with the rebar you should be good to go.. and like neil said it may add too many additional stresses.... and most of us have enough stress already (snicker)
Keep going
Mark

[fxpose]

Thanks guys! Early this morning I removed the column, added additional joists, and nailed down the bottom plywood form.

[fxpose]

I think prepping for a suspended slab was far less labor intense than filling and tamping/compacting that area will fill material.

[ThisOldGarageNJ]

Hey FX,
Looks good and I dont think your gonna get it any more solid any other way, Nice job tying it all together.. When you pouring ??

[jmhepworth]

Nice job with the steel. It's nice to see I'm not the only one to over-engineer that part.

[fxpose]

Thanks guys! So far, I'm pretty happy with the way things are turning out. I will be pouring concrete today and contunue work in the next area.
I am just glad I'm not paying someone else to do this job. Concrete and blocks are cheap, but I'm spending a whole lot more money on rebars.

[fxpose]

Another slab down...