calculating form height averages

[capnquick]

I need a quick reminder on shooting the grade of a lot and converting the measurments to find the form height average of the foundation. Highest part of lot will 3 boards or 18". For instance the other corners are (converted into inches) 64", 56" and 40".
If the tallest part of the lot was only 7" to convert to 18" do I add 11" to the other measurments too? HELP - out of practice and confused!!

[roger g]

That's why I have always liked construction. There is always something to learn because I haven't a clue what you are talking about and maybe I'll learn something:)

roger

[capnquick]

the form height average is used to find the average height of the slab if the lot has a slope. When you set your form boards some corners may have three boards (2 x 6) and other corners may be 5 feet tall (ten 2 x 6's). Take the four tallest corners and add them up and then divide by four. This would be the average height of the slab.

[Rich]

What's your governing point? The 18" vertical that you mentioned? And the measurements you gave - are they story pole measurements from the eye of the level or actual elevations above/below a benchmark? I'm assuming they are story pole dimensions because you say the high point is 7".

[roger g]

hey capnquich. I'm curious as to why you need to know this figure. And once you have it, what use do you make of it. I used to be a draftsman for EFCO (Economy Forms Co.) which is a huge concrete steel form company with divisions all over the world and I don't remember this type of question. This was many years ago so things probably have changed .

roger