Monday, July 28, 2008

Footings and Foundations 101

So...Curt informs me that he didn't even know the difference between footings and foundations before I (probably none too gently) corrected him. But, if he didn't know the real meaning of the terms then I figure a little tutorial could do other people some good.

Here we go. Carmen's brief and not very professor like Footings and Foundations 101.

This is a pretty handy diagram that I just took the liberty of marking all up with my pink summaries.

This was just our footing.
The hole through it, on the off chance you were wondering, is for a drain system they install on both sides that they connect to a sump pump in the basement, (hopefully) keeping the basement dry in the non-dry state of Michigan.
The little loop of rebar sticking up is used (I think, not something I've really seen before) to tie in the slab floor when they pour it.
**Update, the loop is actually used for braces that they put up to support the foundation walls after they strip the forms but before the concrete is cured**

Foundation wall.
They pour this on top of the footing after it has dried a bit and gotten some of its strength.

No, they didn't just dump their extra concrete on the ground to get rid of it...this is a spot footing.
They will pour the concrete floor right over it, but this is a spot that they will be putting in a pillar support in the basement.

So what is the purpose of a footing?
Well, when you build a pyramid out of blocks you start with a wider base to make it sturdy. But what makes it sturdy is that the weight of the upper blocks is being spread around a bigger area touching the ground. Same concept here. The footing takes the load of the foundation wall (and thus the weight of the house) and distributes it out over a wider piece of ground, making it more sturdy.

Well, that's the end of class time, the difference between cement and concrete.

1 comment:

Alan said...

Watching your house go up is fun, but getting a free class in construction and house parts? Awesome.

Tell Curt he obviously didn't watch enough construction programming in Master Control...

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