Re: Porch construction/massive footers OK?
Like wow man, you are almost as much a gluton for punishment as I was (am?). You didn't say bags of what, portland cement, redi-crete or what so I assume redi-crete. You didn't say how big the bags were... I have been in areas where the predominant size is 60lbs and others where it is 80lbs (if I recall correctly). A pallet of 60 pounders weighed about 3500lbs, including the pallet. I could carry a pallet of redi-crete plus several block and misc stuff but was driving my customized TurboDiesel Ram 3500 with extra leaves in the main spring packs, in the overloads, and had air bags between the frame and rear axle. Still wheel barrowing all that for a hundred feet eveyr few days and opening all of it and lifting it up and pouring it into my mixer was not a joy.
I am particularly currious about your statement where you are going to mix a fair quantity "by hand". As far as quality, you can make good mud from redi-crete if you are willing to add some cement to raise the PSI and don't add too much water. A stiff mix (well stirred) is desired over soupy stuff. There are a couple terms that get incorrectly interchanged: placed and poured. In general, concrete that is easy to pour will not cure to a final strength nearly as great as well stirred but fairly dry (stiff) mud. Slump tests are a valid concern and can be used to good effect with your premix company if you go for a delivery. Tell them what psi mimimum and slump maximum you will accept with the provision that you will reject the load if it fails slump. Often they will go to some effort to exceed your requirement by a fair margin to avoid a possible rejection. Same story with 4000 psi or whatever. They will often excced your spec as cheap insurance. Be careful that you don't let the driver or anyone else add too much water to make life easy for them as it makes your strength factor go way down.
I am a more is better kind of guy too but there are diminishing returns once you exceed reasonable engineering requirements. I often overbuild out of ignorance. If I don't know how much is enough, I typically go bigger stronger better until I am comfortable. That is why I hired a consulting engineer (soils engineer and foundation/slab expert, professional engineer with E&O insurance) and two operators with a drilling rig to find out what my soil's strength is and how much foundation is going to be enough. Besides, now that I know how much is enough, I know what I need to do to exceed that by my personal comfort level margin.
Strength of 'crete varies bunches. I have been demo'ing a foundation and sidewalks where a house was removed (sold) and some of the flatwork was of a different era from the rest of the house. At least one of the builders knew concrete. Two of us were taking turns with a 14 lb sledge and had a devil of a time breaking some of it into pieces no more that 1300 lbs so my pallet forks/FEL would lift it. Some of it was nearly impossible while that from a different time period was easy. Big difference in strength.
Consider that time is a valuable resource just like money. Is mixing all that crete the highest and best use of your abilities at this stage of construction? If yes, give it a whir. Typically the problem with sweat equity is that a guy who would make/save more money acting as manager, general contractor, facilitator, gofer, quality control inspector ends up doing some truly low end jobs BECAUSE HE CAN. I would guess that with a little planning you could save 25% of the cost of a house/project by being your own general contractor. Most folks can't save 10% with a hammer and saw. I was real slow to learn this lesson and still relapse all too often. Just because you CAN do some job doesn't mean that you SHOULD do it.
Let us know how it turns out.
Patrick
