footer question
- Thread starter 06manvan
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Big Bad Dad
Well-known member
Codes vary from locality to locality depending on soil conditions and frost line depth. Need to ask your local Building Office.
rburke65
Well-known member
Call your local Building officials. Here locally all footers are 24" wide and 12" thick. Good luck.
TAMPAGT07
Well-known member
rburke65
Well-known member
Ha! Maybe they are where you live....but not here.
Cyberbear
Well-known member
Whatever size they need to be, use plenty of steel. More steel makes up for weak concrete and is cheap insurance against cracking later on. If you are pouring a slab, the same thing applies.
Zeke
Well-known member
Well, you do need to ask your local AHJ but in general with no exceptional conditions like frost line or sandy soil, you would use a 12W x 6"H, 12" down on undisturbed soil down with a 6" stem wall coming 6" above grade. So it's an inverted 'T' 18" high. That's VERY generalized and soils must be tested for composition and compaction unless your land is common to many buildings before you in the nearby area.
Footings are used to hold buildings down as much as they are to hold them up. Your metal building and the openings you choose may have a wind load consideration for you local weather patterns in which case you may need more concrete.
And if building on a slope, you need to get down to undisturbed soil all around.
larry4406
Well-known member
Here in northern va footers for houses are 16" wide, 8" tall, and bottom of footing on solid undisturbed soil not less than 24" below final grade.
matt_i
Well-known member
I built 16" wide, 9-1/4" deep, the depth of a 2x10. Reinforced with 3pc of #4 rebar which are cross-tied roughly every 3 feet. Not sure the cross-tying does any good other than to keep the main bars where they are supposed to be.
IMO, for a single story garage the footer is for getting below the frostline and to distribute the load on the soil. I know many people who poured 8" trench footers with good results, but I think using the footer is going to be more stable for a longer time.
Building on undisturbed soil is key. If you overdig, fill with concrete.
IMO, for a single story garage the footer is for getting below the frostline and to distribute the load on the soil. I know many people who poured 8" trench footers with good results, but I think using the footer is going to be more stable for a longer time.
Building on undisturbed soil is key. If you overdig, fill with concrete.
Last edited:
ms fowler
Well-known member
Footing widths vary depending on the soil bearing that is available. Also varies depending on type of wall that is supported on the footing. There must be at least 2" of "projection" between the wall and the edge of the footing. The projection cannot exceed the thickness of the footing. Bottom of footing must be at least 12 inches below the ground surface. A quick search showed that frost depth varies from 4" to 10" in NC., so the 12" minimum requirement would cover that.
Although some rebar is good, more is not necessarily better. 2 pcs #4 continuous with a #3 04 #4 ties every 4' should be fine. make sure you support the rebar and give at least 3" clearance to the ground. You want the rebar IN the concrete; not under it. Better to insure that the concrete contractor ( or you if DIY) doesn't add too much water to the concrete. Keep the slump in the $' to 5" range, and order 500 PSI more than you think you need--IOW, if you think 2500 PSI is good enough, order 3000. It is cheap insurance, and most 3000 PSi spec concrete breaks way higher than 3000 PSI unless someone adds way too much water. The interesting thing is that, at least here in the Mid-Atlantic, most 3000 PSI mixes are very forgiving and will tolerate a lot of abuse before they get placed, yet some 5000 PSi and higher mixes fail if you look at them funny.
Best to call you local building official if you live in an area that requires permits etc.
For your metal building, uplift is as important as the soil bearing. Some wind conditions will make the building want to fly. The manufacturer of your building package should have some recommendations for footings--follow them.
Although some rebar is good, more is not necessarily better. 2 pcs #4 continuous with a #3 04 #4 ties every 4' should be fine. make sure you support the rebar and give at least 3" clearance to the ground. You want the rebar IN the concrete; not under it. Better to insure that the concrete contractor ( or you if DIY) doesn't add too much water to the concrete. Keep the slump in the $' to 5" range, and order 500 PSI more than you think you need--IOW, if you think 2500 PSI is good enough, order 3000. It is cheap insurance, and most 3000 PSi spec concrete breaks way higher than 3000 PSI unless someone adds way too much water. The interesting thing is that, at least here in the Mid-Atlantic, most 3000 PSI mixes are very forgiving and will tolerate a lot of abuse before they get placed, yet some 5000 PSi and higher mixes fail if you look at them funny.
Best to call you local building official if you live in an area that requires permits etc.
For your metal building, uplift is as important as the soil bearing. Some wind conditions will make the building want to fly. The manufacturer of your building package should have some recommendations for footings--follow them.
Falcon67
Well-known member
I thought footers are 12" x 12"... (And yarders were 3' x 3')
They are here where there is only UBC code and 12x18 for a garage where there are code amendments. We do not have a frost line of any sort. We also typically have expansive clay, so soil type also makes a difference as noted above.