Concrete Mix question

[crokett]

I will be pouring the footers for the shop porch on Friday. My plan is to dig and pour the two corners, dig the rest, then come back and set the anchors and corner posts. Then I can use those to help level the beam that wil hold up the porch. I want to get the footers and beams in Friday then set the porch Saturday.

Looking at Quikrete's product lineup:

http://www.quickrete.com/PDFs/ConcreteSelectorGuide.pdf

Is there any reason I couldn't use the Fast setting (red bag) as a footer? It has same PSI as the normal stuff. I am not sure Lowes carries the fast set orange bag. I'd use that instead since it gets stronger faster.

[chopnhack]

If your concern is to apply loads to the footers ASAP get the white bag. If not go with the yellow bag and just stake your post's plumb and level. The red and orange bags may set faster than you can mix and pour them and you may end up with cold joints instead of a monolithic pour. I'm sure that your yellow bag is the cheapest route anyway.

[gjat]

There is no reason why you can't use the fast set hi-strength mix. The load you're putting on isn't going to make that much of a difference if it's just for the porch corner posts. Don't over-wet your mix and you'll be fine.

[crokett]

Chop, open time is a concern but I can mix and pour pretty quickly. I generally only mix one hole at a time anyway. I can do more than that but it gets tough to push the wheelbarrow around. I think I will get the orange bags if Lowes has them. I'd really like to be setting the porch floor Friday rather than waiting on concrete to cure overnight.

[pelligrini]

I don't think the red bag would be a good idea. I believe it sets quickly, enough for a post, but doesn't really gets up to strength that fast. You're probably better off with a high/early or their FastSet.

[Hellrazor]

I nevered messed with the fast setting stuff. We always use the regular bags and let them set for a while.

I'll throw you an alternate idea. Do you have a few extra deckbloks or 2x2 concrete pads atleast 2" thick sitting around? Use the concrete for the footers and do the work like you planned. Use the deckblok/pad and some scrap wood next to your footers to take up some of the weight until the concrete is fully cured. Once the concrete is cured you can cut the scrap wood off with a chainsaw or zawsaw and let the footers take the full weight. It might cost an hour of time but it could be well worth it if you are in a hurry..

[chopnhack]

As another poster already said, do not over wet your mix! I know that it takes me quite a while to mix a single bag. Let me explain why, it might seem overkill but the concrete comes out so freakin strong, its worth it in my opinion. If I mix an entire bag, I will set aside the recommended water in two parts, 2/3 of water in one bucket and 1/3 in the other. The goal is to only use a little water from the last (1/3) bucket. I pour out the mix into a mixing trough and with a flat bottomed shovel and a masonry hoe I form a hole in the center of the mix and add a little of the 2/3 water at a time, working the sides of the mix until no more mix will stick to the moistened center mix, i will add more water and repeat. By doing this tedious process two things happen, you are wetting all the grains of sand and cement uniformly and you are using much less water. Keep doing this until the mix is too dry to accept any more of the surrounding mix, at this point you will have to use some of the water from the last bucket. Here is where you have to be careful and really judge how much more water is needed. It is like a knife edge between too much and just enough more...seems like madness, but like i said the rock comes out so much stronger and it doesnt shrink as much as a wetter mix so to me its worth it - also, if you screw up, keep another bag on hand so that if you added too much water you can throw more concrete mix in! it takes about 7-8 minutes per bag doing it this way....and that folks is why if its more than three or four bags yours truly gets help! LOL

[pelligrini]

..and that folks is why if its more than three or four bags yours truly gets help! LOL

Calling in the testing company for some slump tests and break tests?

[chopnhack]

LOL, its a bit much, but believe me when I say water is the devil in concrete, the less the better, no shrinking, etc. As long as you cure it the right way

[pelligrini]

Not quite the same thing, but similar. I've seen some good jobs with smooth finishes and some terrible messes. It all boiled down to that razor's edge of water content while they were smoothing it out.

If we're doing a stained floor I'd much rather pour in a milky gypcrete product as a topping, than to hope the first pour gets done right. Don't have to protect the floor as much during the build either.