Replies

1. 
   Ryan_C | Mar 07, 2001 01:32pm | #1

   *
   the math is easy:

   For a 16" wide footing, use 2 pieces of 5/8 rebar

   For a 24" wide footing use three.

   The answer is always 5/8 because that's what the lumberyards sell.

1. 
   Mike_Smith | Mar 07, 2001 01:58pm | #2

   *that's the basic rule of thumb,johnnie..but if you are in sseismic zone.. i don't know how you avoid the PE...check with your Bldg. Inspector..

1. 
   Johnnie_Browne | Mar 08, 2001 01:00am | #3

   *I'm not trying to avoid the PE, they are just too busy this week to answer a peon question. They gave me a stack of books and told me to figure. But I got stuck, I was hoping they was a PE in the house to help guide me the right way. Not really looking for an answer but the correct path to the answer,

1. 
   david_bogaty | Mar 09, 2001 03:23am | #4

   *don't want to be a nit picker, but typical calculation for compression area of concrete and steel stress are in units of sq in. not weight.# 5 bar (5/8) 1.043#/'# 4 bar (1/5) .668#/'As mentioned above you may want to have your calc looked at by codes. Good luck.

1. 
   Johnnie_Browne | Mar 09, 2001 04:34am | #5

   *Yes, that is what I,m trying to get to. I have calculated the weight of the footing,soil, walls,roof, dead loads and live load. I have the bldg weight to psf. Now I need to get to size of steel. by calculation not by what the hardware store sells. I must prove the calculation.

2. 
   Tom_Moller | Mar 09, 2001 06:24am | #6

   *you can use a few big ones or a bunch of little ones. There is usually a best cost configuration. Things are also complicated by how deep your footing is and where the steel is located. I'm glad to hear that you're reading the textbooks. That means you're on the right track. But don't get discouraged if you can't get it all together in one week. A bright student usually takes at least four years to get an engineering degree. Hang in there and good luck.

2. 
   Johnnie_Browne | Mar 09, 2001 06:24am | #7

   *
   Cannot get the pencil pushers at the office to give me the time of day. I am calculation the size of my rebar in the footing. I have got to the point of weight to psf. I cannot figure how to get from this point to size of rebar. somebody give me the forumla please.