I am getting ready to pour footings for 8″ block foundation walls and know I need to dig and pour step footings to deal with the slope, but am out of my league as to how to do it…. any good simple books out there… I’ve poured 4 monolithic slabs/turn downs and built my block walls on top of the slab…simple,… just get everything level and to proper grade..these new walls will be for crawl space instead of basement and i don’t know how to keep the concrete from running downhill in the stepped footing….
thanks!
Replies
couple 2x and a board to block, pour the mud a little dry and watch the vibrator
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Haga su trabajo de fricken
Same as Brownbagg, but with a whole lot more words.
Make and set your three sided form for the vertical section and when you pour, start by setting enough mud in the vertical to squeeze some out the bottom and start a build up in the vertical. Vibrate the vertical one time.
Move to the bottom section and Place a good bit of mud in front of the extruded part before you let the V-man vibrate that extrusion and then make sur he keeps it far enough away from the verticle form that the cone of liquification doesn't ravel under the form. Then pour around to the other vertical and repeat the from-the-top-first placing, then come back to the first vertical.
Have your vibrator man mark off the depth to the top of the mud already in the bottom and place about 6" more 'crete on top of that. That 6" of mud should be vibrated by sinking the V-tip to just barely tap the previously set mud once at each 3"OC, then raise the V-tip and continue pouring and never again let the V-tip reach all the way down to the bottom layer of mud.
That tapping action will consolidate the first and second placings without liquifying the first placed 'crete and thouroughly vibrate the first 6" of the second placing. Since the cone of liquification of a vibrator only travels a couple of inches downwards, you will never fully liquify the first placing and it won't flow out of its' proper place.
Clear?
As Mud?
SamT
Edited 8/28/2007 9:43 pm by SamT
I will add what may be some obvious details to what has already been posted.
Make your steps in the foundation fit to the block increments.
(8" high increments and multiples of 16" lengths.)
The upper section of a step in a footing must run over the lower section by at least the same dimension as the footing is wide.
(16" wide footing requires a 16" length of double depth footing for example)
"Poor is not the person who has too little, but the person who craves more."...Seneca
" The upper section of a step in a footing must run over the lower section by at least the same dimension as the footing is wide.(16" wide footing requires a 16" length of double depth footing for example)"Good point!Robdog,That's for block, and means the vertical footing will be square in horizontal cross section. For poured walls, it's the same Dim's as the other footings.The upper wall must extend over the lower wall by (1/3 -3/4) the height of the drop. See *your* AHJ for exact numbers. Codes differ.SamT
hey thanks y'all! all new and all good info....any thoughts on some good pictures or even a good general book on the subject? and.......at some point in this pour I'm going to need to go from a short crawlspace wall to a full height (13 cells) basement wall...can I somehow make that jump in one step or do I need to ease it down?
thanks again!
The upper wall must extend over the lower wall by (1/3 -3/4) the height of the drop. See *your* AHJ for exact numbers. Codes differ.SamT
robdog, Typically the steps are laid out so as to keep the footing below grade by enough to meet the code requirement for frost. That requires looking at your ground contours . I don't work around block much so can't comment on the best step solution for that material."Poor is not the person who has too little, but the person who craves more."...Seneca
we do alot of step downs where pipe has to exit a wall. it easlier to break a block than go through a footer..Haga su trabajo de fricken
This is on poured foundation. I have 4 ft step in footings. There is no overlap. In fact there is a gap. Don't remember the size, but might be 18".But this is a little different. It is a T intersection..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
A stepped footing? You said footing correct? I've seen stepped foundations, but not stepped footings. I've never seen this done anywhere. Usually the footings are level all the way around.
stepped footers....
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Ok, I did a little research and found some info on stepped footings, so I guess they can be done and I was wrong. but I've still never seen them done like that. It looks like you would just "overlap" the sections of footing where there is to be a drop in height. So if you're footing is 8" deep, now you're going to have to pour 16" in the overlapping section.
See "Build and Repair with Concrete" page 13 (it's the little book with Don Knotts on the cover)
How about a 4' difference?SamT
.... any good simple books out there... They have this new system called a LIBRARY and you don't have to buy anything, LOL, luck.