Is This Correct?

Tom M

I have a 6000lb point load going through a house to a new lalley column. Assuming 2500lb soil capacity per sqft, 6000/2500=2.4 so I am going to just do a 2'-6" x 2'-6" spread footing. This is 12" deep footing with say a 4" slab thickness. I come up with 13 80lb bags of concrete. This seems like too much to me. Is it the correct amount? The damn architect is over building everything with these massive steel connectors and laminated post above I am just trying to verify whats going on.

reveivl

2.5 ft x 2.5 ft is 6.25 sq. ft. not 2.4 sq. ft. That said, a footing of 2.5 feet square doesn't seem like overkill to me, but then I'm not an engineer and am not signing off on it. Presumably someone is? If they are, then do it the way they say or it's your fault.

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Tom M

6.25 sqft 2500lb per sqft equals 15,625lb capacity footing for a 6000 lb point load is more than double. That not over kill.

Tom M

This was a simple alteration. I had to take down a bearing wall for a couple with a small home. I spec'd out a Anthony power beam and sketch showing how it would be supported. With that I had a manufacturers print out from the lumber yard for approval of the span. The home owner submitted the permit apllication. The town insisted on an architect to do the drawing. So this hassle becomes bigger cause this rookie architect opens a book and calls for laminated posts which are now special order/ non-stock material even though the manufacturer calls for 2 2x4 and steel plates connectors that are designed for new construction only will not fit old work and also have to be ordered. The footing is huge as well even though I told him we had a tight area to work with. This is why people dont want permits for things like this, try to do the right thing and we have a month long ordeal over built and unneeded cost jacked up. All my measurements and info to boot, the guy didnt even come out to pull his own numbers. I have no patience for crap like this.

tgeb

I calculate 13.95 bags @ 80 lbs. each.

I am figuring that you will do a 1 foot thick footing and then set post and patch 4" thick slab.

As far as 2.5 feet square being to large for a concrete pier footing, we rarely do any that are smaller than 2' X 2' and some get much bigger, we just poured some last week in an addition and had 2 - 3.5' X 3.5' and a few 2' X 2'.

It was not a big house either.

Sakrete has a data sheet for quantities of material in thier different size bags.

http://sakrete.com/downloads/product..._Datasheet.pdf

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Tom

www.gebcon.com

Tom M

Thanks for the confirmation and the link. I already had that one but its all good. I am achoring that column exactly like you mention, in fact I was considering doing a fast setting cement to get strength fast. My first thought process was 2500lb per sf and we need 6000 then double is 5000 ect...and I think the architect see it the same way... but then I say 6.25 x 2500lb per square foot is really 15k plus so reality is I only needd a 20x20 instead of a 30x30. Its all petty and insignifacant at this point.