# How to measure and add foundation to an existing home.



## ISH (Nov 1, 2005)

Okay, customer wants a room added to his house. Contractor pours the slab and I found it is out of square. I measure from the corner contact point of the existing house and the newly added slab to the opposite outside corner of the new slab. Did the same thing on the other side. I found one side to be shorter than the other by 8". I did my 3' / 4' / 5' measurement on the corners and found it off by 1 1/2". The concrete guys are telling me the house is not square so its throwing the ne slab off. What say you?


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## Glasshousebltr (Feb 9, 2004)

Pull from the far end back down towards the house on both sides, mark the same distance with a ref point, then check for square leaving the house out of the picture.

Bob


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## ISH (Nov 1, 2005)

*Measurement*

Thanks for the reply. I took length measurements from the house out to the edge of the new slab and they both measured 22'. So am I corect to assume your method would show it off? The concrete guy said the outside is a little off.


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## camas (Oct 21, 2005)

If the house shares one common side of a new square addition then the house being "out" has no bearing on the new pad being square (assuming I'm picturing this correctly). A square pad is square whether it abuts another square or hexagon or a friggin circle. Do the 3-4-5 from the edges of the pad that don't touch the existing. If it's off, it's off.


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## Glasshousebltr (Feb 9, 2004)

whow, just re read that, 8" in 22' is a long way out, you should be able to easily see that.

My telepathy tells me a concrete fella will be using a jack hammer soon.

Bob


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## camas (Oct 21, 2005)

My telepathy tells me that this is a concrete guy who owns his own jack hammer(s).


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## Glasshousebltr (Feb 9, 2004)

If he's pouring like that he might only have a 74 impala wagon with a wheel barrel tied on top.

_" Me's and delmar's gons to opens up a biznus ma "_

Bob


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## ISH (Nov 1, 2005)

*Concrete Guy*

Well your almost right........it was not a 74 Chevy Impala, it was a AMC Pacer. The wheel barrel fit better inside. 
Oh, the concrete guy still feels its the houses fault.....after all, he has been in conrete for 40 years..........

But all jokes aside, thanks! I knew the answers but its good to see your not crazy. Lets be real, kids in school today are taking "new math" classes....maybe we're to old.


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## Glasshousebltr (Feb 9, 2004)

40 years?.....I'd say he pi$$ed his life away.

Bob


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## bob the builder (Oct 6, 2005)

ISH said:


> Okay, customer wants a room added to his house. Contractor pours the slab and I found it is out of square. I measure from the corner contact point of the existing house and the newly added slab to the opposite outside corner of the new slab. Did the same thing on the other side. I found one side to be shorter than the other by 8". I did my 3' / 4' / 5' measurement on the corners and found it off by 1 1/2". The concrete guys are telling me the house is not square so its throwing the ne slab off. What say you?



that should be fine if you use 2x12's for studs.


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## TimNJ (Sep 7, 2005)

Where are you building? Slab on grade...no footings or block work? If all they did was pour a slab on the ground, get a concrete saw and have them cut the slab so it is square.


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## K2 (Jul 8, 2005)

I say get a straight line on the front of the house then go out the addition dimension on the straight line, turn a 90 with your theodolite or all station, go the next dimension and turn another 90 back to the house. If the corners up against the house are not 90's so be it. You have a straight front line and 2 outside 90's. That is how I would do it anyway.


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## K2 (Jul 8, 2005)

OOPs. Straight front, one 90, fudge the back. Keep the ridge straight.


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