I made some comments in another discussion about how they do slab foundations here. here’s a couple of pics, two different slabs. You can see the outside formboards (well-used plywood) and the fill material used to take up the space. One slab shows a couple of sonotubes, so apparently the engineer saw the need for some point loads.
In both cases, I show the low side of the lot where the most foundation will be showing. Both of these are about 6-8 feet high, and you can bet the brick ledge will be just a few inches below the top of the forms.
“When asked if you can do something, tell’em “Why certainly I can”, then get busy and find a way to do it.” T. Roosevelt
Replies
Fill-in-a-bag? Whazzat?
Must be cheaper than trucking in fill and compacting it, plus, the bagged stuff can be built into a wall edge, leaving a stemwall thickness between it and the form edge to make a stemwall.
On the other hand, why not form both sides of the edgewall and then just do the fill in compacted lifts?
Is the bagged fill work done by the excavation contractors?
Iz cheeper. Mucho cheeper, amigo. The slab and footings are all poured monolithic. if you formed both sides of the exterior wall, then you would have to strip two sets of forms, then backfill, and pour again.
This way, the imported laborers can form the entire foundation at the same time, and make one pour.
There is not much excavation work done here, other than clearing the site. The ground is much too rocky ... lots of limestone with about 6-8 inches of top soil. I think the formwork and fill and all is done by the concrete sub.
And it's not fill-in-a-bag. very hard to describe. They use rolls of 6mil visqueen, cut into short lengths. lay down a piece, pile fill on one side and the middle, then fold the other side over and pile fill on top of that. Maybe think of it as a stack of soft tacos.
Also, typically they will cover everything with another layer of visqueen, including the sides and bottom of the trenches. Then the plumbiong and in-slab electrical, then post-tension cables and wire mesh. Sometimes the cables and mesh even end up in the middle of the slab, but only by acident.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Edited 12/23/2005 6:48 pm ET by FastEddie
Thanks for the pics Ed - it was I who asked in the other thread. Never seen anything like it. Pretty cool. Bad pun about the soft tacos though :-) How much is concrete per yard down there? It's about $86 here for 3000 PSI here. Gotta be cheaper there - as much as you all end up dumping into those "holes". Looks like a 50+ yard pour, easy.... It looks like in the pics they haven't finished forming up. Is there a bunch of steel still to be added? Who buys the creete? The sub or the GC?
Yes there's a lot of steel left out in the pics. Some skinny pieces in the bottom of the footings, supported by the absolute minimum number of stirrups, then #4 bar about 12" each way in the slab, and post-tensioned cables. Many times the gc buys the concrete. The sub does the forms, fill, rebar, placing and finishing.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Any chance of, at some point getting a pic or 2 of the post tensioning cables, and specifically the tightening mechanism? We just don't see this kind of concrete work around here.
For a slab foundation on a non-flat lot, we would do a masonry stem wall sitting on footers. The foundation would then be backfilled with gravel and concrete placed on top, and supported around the perimeter by a lip in the masonry. Grade beams may or may not be incorporated depending on site conditions, etc. On the other hand, for foundations as tall as you picture, we would just build a crawl space. The fill can get awfully expensive, easily into the $ thousands, and, generally (IMO) a wood floor is more comfortable to walk on and is better in heating climates unless you want to go radiant.
All: For some of you who may not know why I asked "who supplies the concrete" here are the things to be aware of:
Sub supplies concrete: Normally this would be a turn key situation. Sub marks up price of concrete, but will not waste concrete or other materials - GC still has to watch to see that everything being poured is thick enough and enough steel is placed. This is very hard if not impossible to evaluate after the fact. Some sort of specs should be set up ahead of time - or at least shown on the plans. This is the most convenient method for the GC as the sub should be able to give a turnkey price ahead of time, thereby being the safest route but may be the more expensive method.
GC supplies concrete: Sub may over-dig and otherwise not be too thrifty with the concrete. This could easily result in an extra $500 or maybe even $1000 in material cost. GC has to examine excavations closely to be sure that they are done properly. This is particularly true if the sub is charging by the yard. Still, this is potentially the most thrifty route to go.
Conclusion: People who think they can GC a job from their phone while they sit in their office have another thing coming....
Edited 12/25/2005 8:16 am ET by Matt
I be afraid of the soft taco, it looks like a settlement problem that will crack the slab.. 2+3=7
it looks like a settlement problem that will crack the slab
Oh no, the young couple buying their first house from a set of cookie-cutter plans at the builder's sales office in the subdivision, has already heard all their lives (if they gre up in nay of the larger cities in TX) that "All slabs crack."
Thus, they have no worries. Builder makes a sale, so that helps leverage the other 9 slabs he's started on spec. Couple gets a brand new house and does not know any better. After all, how could it be better than "brand new"?
To steal the line overheard on Christmas Eve: "Ignorance is bliss; Knowledge is worry, ulcers, wrinkles . . . " (Said by the FoF who is a remo contractor.)Occupational hazard of my occupation not being around (sorry Bubba)
Matt,
Your points are great. We have most of your concerns covered as follows:
As the GC / Builder, I buy the concrete. My sub charges by the square foot, and the foundation plan is typically an engineered plan for the particular site. We generally do a soil test / report that goes to the fondation engineer. Beam dimensions, steel and steel configuration, slab thickness, etc. are all specified and detailed in drawings.
My foundation sub has worked with me for 25 years. He does beautiful work. I hope he does not retire soon.
People who think they can GC a job from their phone while they sit in their office have another thing coming....
You ain't just whistling Dixie with that statement. I have a super, but I do not take on more than allows my personal involvement. 4-6 custom homes per year is enough for a good comfortable living and enaqbles me to oversee my super on site and give my clients lots of personal attention.
Edited 12/25/2005 10:15 am ET by txlandlord
Edited 12/25/2005 10:21 am ET by txlandlord
>> I have a super, but I do not take on more than allows my personal involvement. <<
What I meant was that someone reprisenting the GCs company needs to be on site on a regular basis - at least daily. I'm a superintendent. I spend 80% of my time on site. The owner of the company usually visits each house I build a few times. I have built some houses that he has never been in - to my knowledge. There is a vice president too, but he is not involved with the single family home aspect of things, and, again, to my knowledge, he has never been in a house that I built. They may check up on me when I'm not around, which I'm sure is not intentional, more of just a drop by and see how Matt's houses is going kind of thing. There is a sister company owned by the same guy, and between the 2 there are about 8 supers. Maybe on the sister company their VP and the owner is more iinvolved. They build the high $ houses.
In another recient thread some home owners and owner builders were ranting and raving about how you should be able to hire a subcontractor and have everything come out right with little to no involvment from the guy who does the hiring. I just smile :-) and wonder why I have a job. :-) With some subs that may be true, but still someone needs to be around to answer questions. I find that if no one is around most workers won't ask - even though I'm always available on the radio/phone.
Even though you have been using your concrete sub for 25 years or whatever you said, I bet someone still takes a glance before the pour - at a minimum.
I bet someone still takes a glance before the pour - at a minimum.
Takes a glance? I am personally out there when we set forms, check forms and steel configuration as it proceeds and I am personally there when we pour until the last truck is poured out.
Hey, one thing about your job is that it will easily tranfer into doing your own homes when and if the time comes.
The "Take a glance" was kinda a toung in cheek statement. And, I bet as complex as your house's foundations are there is almost always some kind of at least small error.
I had one this past summer where the surveyor made a mistake. A masonry crawlspace wall was 3" out of square in 4'!!! How could those brick layers not notice it and did they not think I would call them back to fix it? I didn't see it until they were done and cone. We could have so easily "winnged" the layout right then and there but Nnnnnnooooo! Well, it all came out fine after some quick tearout, and the surveyor absorbing part of the cost.
I was not at all offended by "Take a glance", but it does happen. One of my framers told me he never see the builder, and when he calls to report a problem or needs some direction the builder tells him to work it out. The builder builds 7 - 10K SF homes.
I visited one of his sites in the frame stages looking for my framer. He was 3/4 way through the frame and the place was a wreck. No clean up or drainage grading after the foundation pour, puddling, scrap and left over materials all over the place. He had all of the frame material dropped at one time for a 7000 SF home.
All of this surprised me as we are just the opposite. We provide drainage grade and clean up after pour, making it easier for the framer and others to work. We drop materials in common and effective increments (1st floor walls / floor joist and sub-floor / 2nd floor walls / ceiling joist and rafters / cornice and decking / windows and doors).
Comments on my comment: "Your description of your job and what happens in the homes your employee builds will make it easier if and when you decide to go out on your own." Do you think you will ever build for yourself?
>> Do you think you will ever build for yourself? <<
Maybe, but my wife is dead set against it. I guess she has heard about too many builders going bankrupt. Also, it is very hard to get building lots around here. I was in business for myself a while back doing home improvements, but didn't do that well - seemed like there was always someone who could do it cheaper and my hit rate for "free estimates" was not too good. There were weeks with no money coming in. My business plan was to always do a superior job, and give great customer service, but that seemed to be not what people were looking for. I'd at least like to do the 2 year build and flip drill, but DW doesn't want that either - she wants stability. The good news is that if the place I work for now gives me some more raises and bonuses likes the ones I just had it just won't make $ense for me to leave. Also, I'm kind of at a place in my life where I have everything I need, and want to focus more on quality of life. The last thing I want now is a bunch of responsibility and paperwork outside of the regular 7:30 - 5:00 hours.
Sometimes the wives have great insight.
My motivating mantra "Happy wife, happy life."
Our pastor says that it simple yet contains great wisdom.
Thanks for you input on post "Deck Choices". I now have enough info to allow my client to make an informed choice.
All the best.
TX
Hmmmm, 4 - 6 houses a year.
I guess that means 400 to 600,000 a year in your pocket! Acording to another thread!!!
Doug
We build custom on the owners lot. We are not spec builders (although we are considering some soon). Construction cost range from $350,000.00 - $1,000,000.00 +. Apprasal values are usually $500,000.00 - $1,500,000.00.
We funnel $1,400,000.00 to $2,000,000.00 through our company each year. After all bills are paid it provides a nice income.
We also own 10 rent properties and are trying to develope 100 acre parcel I bought 5 years ago. We are taking a poorboy approach to the development, not wanting to take on huge debt counting on a future payoff.
Life is good. I can remember when I started on my own in the early 80s, I was pleased and functional with $35,000.00 - $50,000.00 a year.
I started in the buildiing industry as a framer in 1971 and never looked back, always aspiring to greater heights. My sucess is self made as I did not have a builder dad or close and consistant mentor.
I can say with confidence that our success has been from applying an operative lesson I learned in Sunday Schoopl as a small boy: Do to others as you would have them do to you....(amplified) even if it means a loss....a good name is better than great riches....quanity is a natural bi-product of quality.
I would encourage those who truly have what it takes to be on their own to go for it.
I would be glad to provide consultation to those interested in lengthening the cords of their tent (expanding and growing their business).
TX
I appreciate your feedback. I had rental property for a while myself, then came the early 80's in Iowa and it wasn't worth the ground it sat on! I was lucky to get out with the shirt on my back. Never again, for me that is. I own some land in Iowa and two houses but one of them my mom lives in so I don't have to threaten eviction very often! <G>
I was making an off the cuff remark about the income because of the thread that Johnny started that all GC's are making 100,000-175,000 grand on each house they do.
Maybe you didn't see it, just assumed that you might of.
Doug
OK, now I understand. I had been reading Johny's post and responding with great interest.
I have not had time to catch up on Johnny's progress.
Someone should copy his post to a file and let him read them in 10 - 15 years.
that means 400 to 600,000 a year in your pocket!
I'll bet he'd agree that some years it's only $400 <g> . . .
I'm still hoping for $40 ahead on Saturday.Occupational hazard of my occupation not being around (sorry Bubba)
I'm still hoping for $40 ahead on Saturday.
I dont know what I'd do with a windfall like that!
Doug
Slabs way out of the ground....ugly.
We did some in Memphis, TN years ago (live in TX now) on rolling lots. We set forms so that the brick ledge was just above ground level. In some cases we had steps in the form work ....7 1/4" per step to follow the undulating terrain. When finish grading took place it looks as if wall is entriely brick.
The whole process took careful thought and planning, but the results were fantastic in appearance.