# crawl space under a garage?



## fred54 (Dec 1, 2010)

Flipping channels yesterday and on "This Old House" they had a house with a garage with a crawl space underneath. In New Jersey I have never seen that before nor could I understand why it would be done. Why not just pour a slab and be done with it?

What is the method to span the opening? What kind of support is needed? 

It must be fairly common because they seemed nonplussed about it but I was really taken aback. It seems like a lot more work and expense.

Can you guys for whom it is fairly common enlighten me? I am just curious.

Thanks!


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## Bad Boy Biker (Dec 12, 2009)

We have never had a crawl space below a garage. But we have in several cases of hill side lots put a garage below a garage.


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## CJKarl (Nov 21, 2006)

When I was a kid my neighbor had a full basement under his garage. He said pouring over steel was cheaper than filling. Maybe, but guess what? 40 years later the supporting steel rust out. They blocked up the doorway in the basement, sawed the garage floor in to chunks, pushed it in the hole, filled up to grade with process gravel and poured a slab. Hmmmm, what's cheaper now?


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## greg24k (May 19, 2007)

I don't know the reason was, but they use steel deck, as they use on bridges and pour concrete over it. Composite metal decking can reach spans of 30' in shored construction.


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## Chris Johnson (Apr 19, 2007)

There are several products, like Greg has shown, I have used Coreslab as well as InsulDeck. 

I am just finishing one where we put a theater room below the garage. It is cheap living space


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## Rockmonster (Nov 15, 2007)

Ditto on what these guys have said. But I think the OP wondered about a garage over a 'crawlspace'........I am having a hard time imagining why _that_ would want to be done........


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## overanalyze (Dec 28, 2010)

We r doing a sistern under a garage now. It will have a concrete beam down the middle then the floor poured across the beam.


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## Frank Castle (Dec 27, 2011)

I've seen this once and also had no idea why you would do it that way. I didn't even like the thought of cars parked above my head when they wanted to cover the dirt crawl with plastic.


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## skillman (Sep 23, 2011)

I had many garages and have never parked a truck in it. Takes up to much room from my shop space. I feel sometimes like a hoarder.:laughing: But space under garage floor seems doable and could be a big space saver.


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## jomama (Oct 25, 2008)

I've been involved in plenty of projects that involved pre-stressed concrete under the garage floor for a full basement below, but i can't think of one good reason to put a crawlspace under one...........


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