Replies

1. 
   mikemahan3 | Mar 23, 2021 07:44pm | #1

   Why not just one 36 x 18 footing?

1. 
   aligor | Mar 23, 2021 08:06pm | #2

   Hi,

   Thanks for replying, but I don’t quite understand what you mean. What do you mean by 36x18 footing? Would i use it to support 2 piers & 2 posts that are spaced 18” oc? I apologize if I’m being imprecise...masonry is very new to me so I might be misusing terms

1. 
   mikemahan3 | Mar 24, 2021 03:54am | #3

   Yes, just pour a 36 inch footing instead of the two. Place the two post anchors where the posts will go. Two footings next to each other would work, too.

1. 
   aligor | Mar 24, 2021 09:02am | #4

   Oh wow, didn’t realize that sonotubes get that large.

   It seems like the second variant seems to be called a “combined footing”

   https://www.civillead.com/combined-footing-definition-and-types/#What_is_Combined_Footing

   Thank you very much for taking the time to help me

2. 
   unclemike42 | Mar 24, 2021 12:51pm | #5

   What does the sonatube have to do with the footing?

1. 
   aligor | Mar 24, 2021 01:56pm | #6

   Hi,
   Perhaps I misunderstood what mikemahan3 said:
   “ Yes, just pour a 36 inch footing instead of the two. Place the two post anchors where the posts will go.”

   My understanding is this: a support consists of a footing, a pier and a post. A pier is usually cast in a sonotube. However I’ve seen people use the word footing to refer both pier and footing. Since mike mentioned attaching post hardware to the footing I was assuming that he meant that the both the pier and the footing is 36”.

   Please let let me know what I’m misunderstanding.

   Thanks!

1. 
   mikemahan3 | Mar 24, 2021 08:48pm | #7

   The footing should be rectangular. I've never delt with round footings. Even round piers usually sit on square footings. Yours should be 36" x 18"

3. 
   unclemike42 | Mar 25, 2021 06:43am | #8

   People do call all kinds of things footings, They also use foundation. People call all kinds of things imprecise names.

   footing is the part that spreads a more concentrated load out so that the underlying undisturbed or properly compacted soil can handle the load.

   You could bury a 36 inch sonatube filled with steel and concrete, but that would be more suitable for a cell phone tower. (for an example)

   No worries, however, discussion is a good way to learn.

4. 
   user-7306700 | Mar 25, 2021 02:46pm | #9

   Aligor,

   It is my understanding that footings for such like a deck, when within a certain distance which I forget, of another footing (say for the house) must be at the same depth as the original footing else pressure from the new footing will impact the old footing. Thinking 5 feet might be the distance. What some of the other contributors are suggesting is that while your footing has to be of a certain size based on load (the tables give both square and circular dimensions) that does not mean the entire column has to be of those dimensions. So, you do not have to use a sonotube full of concrete the same dimensions as the footing. Might save you a bit a money/work and back labor.

5. 
   Krunal6501 | Nov 22, 2021 11:03pm | #10

   Oh wow, didn’t realize that sonotubes get that large.
   It seems like the second variant seems to be called a “combined footing” https://civiljungle.com/combined-footing/
   Thank you very much for taking the time to help me

1. 
   Deleted | Nov 22, 2021 11:08pm | #11

   “[Deleted]”