How deep for a footer?

**KYHUNTER14** · 09-30-2007, 04:10 PM

I am having a 24X36 block garage built and was wondering how deep to dig the footer. The guy who is going to lay the blocks told me, but I didnt write it down. Any of you guys know about stuff like this?

**NonTyp** · 09-30-2007, 04:24 PM

I think 12" deep is the code minimum. We always dig with a back hoe and they will be a min of 12" deep and 24" wide.

**WBBP** · 09-30-2007, 04:33 PM

It is different in different parts of the country depending on your winter temperatures. Non-typical is about right.

**Multidigits** · 09-30-2007, 04:51 PM

12" would be an absolute min. The freeze line in N. Ky. is at least 16" If your footer is down to undisturbed earth, you can get by with a 12" or so footer. Just use a 2 x 12 if your going to use 2 x 12's on your garage door header and clean them off after your concrete is cured.

**6.5x55swedish** · 09-30-2007, 04:58 PM

Up north we always put them in at 4 ft deep because they have to be below the frost line. Driving a concrete mixer around lexington for the past three years I have seen alot of them put in and often they are pouring the concrete level with the ground and it passes inspection..... I personally would dig it down 24 inches and then pour 8 inch deep footer....that would give you room for three runs of block on the footer.

**trader rob** · 09-30-2007, 04:59 PM

i always liked mine 16, i is a bad feeling to see a crack running up your block after a year or so, due to freeze and thaw.

**leeand49** · 09-30-2007, 05:33 PM

Originally Posted by trader rob

i always liked mine 16, i is a bad feeling to see a crack running up your block after a year or so, due to freeze and thaw.

I would go 16-24 inches.Takes more concrete but you need to get below the freeze line or you will have problems later on with cracking block or doors that may stick.

**6.5x55swedish** · 09-30-2007, 06:35 PM

Originally Posted by leeand49

I would go 16-24 inches.Takes more concrete but you need to get below the freeze line or you will have problems later on with cracking block or doors that may stick.

You can dig it as deep as you want and it will take the same amount of concrete. Just the deeper you go the more runs of block it will take to get it back up to ground level. National code for a footer is 6 inches deep of footer mix 2500-3000 psi.

**DUCKDODGERS** · 09-30-2007, 06:45 PM

I believe the code in kentucky is 18". If your county does not make a mandatory footer inspection prior to being poured, ask your county inspector. The place where the permit is issued will be able to tell you how to get in touch with him. I know the concrete is to be 2500 at the min. but I recommend 3500 - 4000 myself.

**predator** · 09-30-2007, 06:56 PM

Originally Posted by NonTyp

I think 12" deep is the code minimum. We always dig with a back hoe and they will be a min of 12" deep and 24" wide.

NonTyp is right, but should add that we dig the footers 18" deep and 24" wide. Then pour the footer 12" thick, that way upon finish grade the BOTTOM of the footer is at least 18" below finish grade, this is to get it below frost line. I like to place 2 runs of 1/2" rebar in the lower 1/3 of the footer.