Drider_it

anyone here pour, finish or set concrete forms?

just wondering what you use for forms.

for driveways we use 1x4's and a metal interlocking keyway joint. most others around here use treated redwood 1x4 for a join. (no pun intended) but in 5 or so years it rots out and grass and such can grow up through it.

for say a building slab or house slab instead of 2x12's we use a 1foot form. build a frame that is 1foot and put a peice of plywood on the front with a 1 3/4 inch lip above it. every two feet we have a spacer block put in. set that bad boy on the ground and put a steak in at ever spacer block. we use a laser transit to shoot them to grade as we nail them up. and a 2x4 going from that stake to the ground for a kicker. then our back ho digs a 18" footing down the side and beams across the slab. we use post tension cables instead of wire. once its all up we put a 2x2 across the top on the inside.. this is for tin ledge for a metal frame up building or a 2x6 for the brick ledge. this way when all is said and done you dont have a gap or a space showing under it all. a week after its poured they post tension people come in and pull each cable putting 33k lbs pressure on each cable locking it in.

cracks vanish .. you can put a cig paper in a crack and once its pulled you will never get all that paper out. heh thought it was cool frist time i saw it done.

if we dont use cables say like on a drivway. we use either wire mats or fiber. fiber in concrete is iffy to me.. sometimes its nice others its a pain.

longest time on a job for us is squaring everything up to set forms. after that we get done from 1 day to a week depending on the type of job.


btw flyash is a pain in the arse. here in louisiana they require concrete companies to put it in the concrete. their way of getting rid of it. this results in longer drying times and once your done get cleaned up that crap will eat ya clothes and skin for some reason.

most companies doing forms work thier wood into the total cost then junk it all afterwards.. hell we build our forms or use lumber over and over we usually get 12 jobs off a board long as it dont break or we have to make special cuts.


anyone need help with concrete forms or ideas they have let me know ill provide what i can to get ya started.

__________________
It means only one thing, and everything: Cut. Once committed to fight, Cut. Everything else is secondary. Cut. That is your duty, your purpose, your hunger. There is no rule more important, no commitment that overrides that one. Cut. The lines are a portrayal of the dance. Cut from the void, not from bewilderment. Cut the enemy as quickly and directly as possible. Cut with certainty. Cut decisively, resoultely. Cut into his strength. Flow through the gaps in his guard. Cut him. Cut him down utterly. Don't allow him a breath. Crush him. Cut him without mercy to the depth of his spirit. It is the balance to life: death. It is the dance with death. It is the law a war wizard lives by, or he dies.

jaco

I have pretty much the same job, in the same state as you. I'm going to assume that you are residential because everything you stated would blow out on most commercial jobs. also, some companies have alot higher percentage of flyash than others, if you have them in your area, LaFarge has a huge percentage. I've heard they make alot of money doing it that way. For everyone else, to my understanding "flyash" is basically just chemical waste that some engineer figured out could be mixed in with concrete and it goes away.... yeah, smart guy. I have also seen it concrete from companies with a high concentration of it do some odd things like cure warts, or would that be burn them off? In any case, they go away.

__________________
"How soft your fields so green, Can whisper tales of gore"
"Thou art god"

slant eyes

hey guys. i live in so cal and was planning on building a little tool shed for my parents in place of one of those pre-fab ones that they need to replace. we have squirrels, possums, snakes, lizards, cats, and all sorts of other animals that find home in the fre-fab shed we have already.

so i was looking to pretty much pour a 2 inch high concrete perimeter and build walls on it out of 2 x 4's and finish them as a wall in the house. any pointers on how to set up for the concrete pouring? and since you stated you have experience pouring in residential establishments, how wide should this concrete perimeter be? thanks in advance

__________________
no man or woman is worth your tears - and the one who is, won't make you cry

question authority, don't ask why, just do it!

jaco

I wouldn't recommend any normal concrete to be poured at a depth smaller than 3-4 inches. The fact that you will have to anchor to it to build your walls would shatter 2 inch concrete. Plus, the weight of the building will be based upon the concrete, so depending upon the weight of the building plus the contents the concrete may have to be about 4 inches thick i would guess if the ground is compact enough. So 4"x6" wall is probably what you're looking at, make damn sure to throw in some rebar, at least a #3 running continuous. There may be some details I am overlooking, but I just got home from work and I am beat.

Ah yes, setup. I would use stakes and 2x4's unless you can dirtform it. No need for kickers but perhaps a small board or two nailed across the top edges to keep the form uniform.

__________________
"How soft your fields so green, Can whisper tales of gore"
"Thou art god"

james t kirk

You should be able to specify concrete with NO fly ash.

The railways here do not allow fly ash.

Fly ash is just a cement replacement. It does make the concrete more workable however, so it is not without its benefits. Or so they say.

Now silica fume concrete is a real bitch to work with. It's so fine that they deliver it to the redimix places in a slurry form. If I understand it correctly, it is used in the production of high performance concrete and helps reduce chloride penetration into the concrete. The problem is it is very tricky to cure and it cracks a lot.

Drider_it

oh we do comerical buildings all the time. thing is with our wall forms.. we have poured many 100x300 or so buildings slabs and none have blown out yet. the idea is to save on material cost. compared to a 2x12 our wall forms hold 70% better in any situation. you have the form, stakes and kickers, then a 2x4 inset on top all around to give even more hold to it. plus the dirt that was dug for the spread footers at beams is places on the outside next to the form. we use a "vibrator" along the inside to smooth out the edges and such. plue it ppt post tension. and when we pull it all off none of it is warped like you can get with just using 2x12.

our slabs are 4-6 inchest thick unless stated other wise. on the sides and the beams its 18 inchest to 2ft deep. like sitting a bowl upside down. with the cable lock system inside it holds to form.

using plates instead of bolts for metal buildings is so nice. just weld the beam to the plate that is inset in the slab. ive seen a high windstorm just up in arkansas remove several "poll barns" yet ours stayed with just minor dmg to the roof.

flyash.. yeah we can get a pour with out it. but some reason they hate to do it for us.

with flyash just takes longer to set up and you can get a crust on top and underneath its wet as all get out. heh nothing like watching someone put a machine on a slab and its still just as wet as it was 2-3 hours ago.


on your prefab building. id go at least 6 inches thick all around. usually what we would do and i call it over kill, is to first make a 4inch footing where you will set up all around. then from there go up another 6 inches with 2x6's over all 1 foot depth this way keeps roots and such outta the surface on the inside. citters have to dig a bit to get under it. and such. make sure if the prefab is made mostly of wood you pull up all wooden stakes to keep the termites away. it be a good idea to spray the ground inside the area with bug spray or such before the building goes up.

also on a prefab, dont know how yours is built but we usualy will stick in ancor bolts. shapped like an L that the _ part goes in with the | part sticking up you just paddle drill holes then set it down on it and slap a nut on the bolt and your done. you can chinch nail with concrete nails or hammer drill down to get an anchor if you want but a bolt holds better then just slapping it down.

also, we will make a floating form. just a board that we pour around then pull it up before it gets hard. this is how you get those nifty porches and carports inside a house to work. heh they just set the building down inside the indentions, but its a so so job cuz of what the building is made of. wood tends to expand so that could be bad.

but over all. id go with 2x6's you can bring the dirt inside them up to 4 inches that way concrete or bagcrete wont get under your boards. either put fiber or put in rebarb and your set.

fiber in concrete. im either way on this. ive seen slabs with wire and metal all inside it crack to eternity. fiber if your slump and mix type is right works just as good or better.

we only pour 3000 or 5 sack on a job.

new orleans would be a blast i bet. we say busy in shreveport, bossier, and benton moslty. tons of suburbs going up all the time in benton. usually get get the house slab, drive and walkways and shed buildings to do.

and we do all this with a 4 man crew. heh why people need a 8-12 man crew is beyond me. granted on days we pour big slabs we use a finishing crew.

reason i love this job so much. the only excerise i get. plus when it rains i get a day off. how many people in factory and office jobs get to do that. plus i make enough that a day or two off like that dosent hurt us that much.

__________________
It means only one thing, and everything: Cut. Once committed to fight, Cut. Everything else is secondary. Cut. That is your duty, your purpose, your hunger. There is no rule more important, no commitment that overrides that one. Cut. The lines are a portrayal of the dance. Cut from the void, not from bewilderment. Cut the enemy as quickly and directly as possible. Cut with certainty. Cut decisively, resoultely. Cut into his strength. Flow through the gaps in his guard. Cut him. Cut him down utterly. Don't allow him a breath. Crush him. Cut him without mercy to the depth of his spirit. It is the balance to life: death. It is the dance with death. It is the law a war wizard lives by, or he dies.

jaco

aye, if you can afford it and know how to do it properly i would go with drider's plan. anchor bolts are more stable than anchoring into the concrete itself but if its that small a shed I dont know how in depth you are willing to get. with drider's plan *and what i would do if it was my shed* the shed foundation will never be a problem short of a severe quake.

Drider- now i realize what youre talking about. Don't know what i was thinking. Yeah we use those types of forms, ive been doing too much flatwork lately it seems. Rots the brain with its ease.

__________________
"How soft your fields so green, Can whisper tales of gore"
"Thou art god"

soundmotor

That is a much appreciated offer!



soundmotor