front porch slab

[Kenneth Rentz]

The house was built in 1986. The pictures were taken from the crawlspace. They show the front porch slab which is sitting on plywood with a 2 x 4 bracing. I have always seen this as a piece of sheet steel I have never seen plywood used for this. Do you think this is acceptable

[David P. Valley]

I don't see the picture.

[Larry D. Kage]

All form boards need to be removed.

[Kenneth Rentz]

pictures uploade now at original message. 1st time little tricky.

[Michael Larson]

Originally Posted by krentz

pictures uploade now at original message. 1st time little tricky.

Kinda small. Attach them as Jpegs

[Kenneth Rentz]

What is the largest size I can upload?

[Michael Larson]

Originally Posted by krentz

What is the largest size I can upload?

Here is a tutorial.
http://www.nachi.org/interactive-tutorials.htm#forum

[David P. Valley]

Originally Posted by krentz

What is the largest size I can upload?

640 pixels by 640 pixels

Tutorial

[David P. Valley]

Ok, I can barely see it now.

Plywood must be removed. It'll rot or become a path for termites.

If this is a concrete slab, that wood is not going to assist in supporting concrete.

[Kenneth Rentz]

See if they look better

[Kenneth Rentz]

What will hold up the concrete. I usually see steel sheet metal to support the slab. If the form boards are removed there will be no support. The slab does not have any steel in it. The slab is about 3 feet across.

[David P. Valley]

Originally Posted by krentz

What will hold up the concrete. I usually see steel sheet metal to support the slab. If the form boards are removed there will be no support. The slab does not have any steel in it. The slab is about 3 feet across.

A 3 foot span of slab will hold itself if it is properly poured on bearing ends. But the plywood that was used to assist in the pour must be removed.

[Kenneth Rentz]

Thanks i did not know if the slab would support itself. Thanks again.

[Richard A. Hetzel]

It's a little chancy to state that the slab can support itself PLUS any live load that may be placed upon it. Concrete is strong in compression, but quite weak in tension, and the bottom half of the slab is in tension. Some minimum amount of reinforcing steel should have been placed in the bottom part of the slab. Imagine heavy furniture like a sofa-bed or a refrigerator being moved in or out. It is fundamental that concrete be supported by steel, masonry or concrete, never wood. Absent structural calculations, if I were writing a report, I would state that it isn't known whether the concrete slab can span even the small distance, and in any event, the wood should indeed have been removed, although it's probably a good thing it wasn't.