My wife and I are planning to build a house this summer and have been sketching many variations of floor plans. We’re really new to this home building gig so I apologize if this is a stupid question.
Are there any general guidelines for optimizing the dimensions of the foundation? For example, I’m coming up with foundation lengths of 12 feet, 5 1/2 inches. I’ve not talked with any foundation contractors but am assuming that they’d prefer to work with running lengths of 1-foot increments and trying to obtain a dimension with “1/2 inch” target is unreasonable.
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Around here, concrete guys like dealing in feet, not inches. If they can't have that, either 4", 6", or 8" isn't too bad. Stick in 1/2" somewhere, and they'll probably round up to the nearest inch while swearing under their breath about the moron who drew the print.
Don't really know how they estimate stuff - Hopefully someone else will chime in about that.
Our dog is finally housebroken. But he keeps forgetting to put the seat down.
It is unreasonable to expect a foundation contractor, to work with 1/2".
You sound very much like someone who is about to get themselves into a lot of trouble. I read nothing that indicated that you know enough about building.
I suggest that your hire a draftsman or architech to put your desires,thoughts,and dreams into a good set of working blueprints. Than hire a GC. If you wish to do your own contratring you will understand, and soon, why 40 year old contractors look like they are 60!
Charlie
But I do wish you the best of luck.
Sorry but I DONT agree with some of these posts AT ALL......I've been doing rnovations for over 27 years.....reckon that "just" may qualify me, perhaps. Thing is......what you want is what you should get,,,,,,,,,,excuseeeeeeeee meeeeee for wanting to go into inches. If youre willing to pay then you should get whatever youre asking for within a 1/16th of an inch. Not saying that one will be so perfect but DON'T friggin tell me you need to be 6" or a foot within! What a bunch of sh&t. If your paying and they promise then.......... Either you're a pro and an expert or your full of excuses. Your a craftsman or a jive #### man
Be well
Namaste'
Andy
It's not who's right, it's who's left ~ http://CLIFFORDRENOVATIONS.COM
If tunnels and bridge foundations can be built within a 1/16", then a house foundation better be within a 1/16". I hope a real concrete man will speak up for his brethren....that's not a mistake, it's rustic
they can build anything you want to any dimension... but what you want isn't neccessarily what you should have..
why you get the 5.5 inches is what some are questioning.......and 12' ? when you get to biding small foundation jobs you will usually pay more for the small ones on a unit -cost basis than the large jobs...
another thing... new construction can usually be designed to optimize all materials.. and foundations can be designed for the same thing .. to optimize materials.. in remodeling...we always have to build and design around existing conditions , so our subs are used to dealing with odd dimensions...Mike Smith Rhode Island : Design / Build / Repair / Restore
Andy & Jeff -
I've measured a lot of foundations over the years, and I've never seen nor heard of one within a 1/16" of the intended dimensions.
Forms and form ties stretch when filled, and the forms themselves aren't perfect to begin with. Don't know how you guys could make such a statement.
The early worm gets caught.
I make the statement based on the fact that it is done all of the time. As others have posted, they get that precision as well. I'm not saying you should do it in a home foundation. That should be based on 4' construction increments for economy (in an ideal situation). ...that's not a mistake, it's rustic
Why the hell would anyone care if the foundation was anywhere close to 1/16th.......even 1/2" would be fantastic! And I'd prefer level, anyway.
That big thing you're gonna build on top of the foundation.....made outta wood.....the house......that can be adjusted ....say 1/4" each way.......to hide that glaring 1/2" mistake!
Who's gonna be next and suggest setting the windows with lazers? Really........sometimes......Jeff Genius has it's limits.....but stupidity knows no bounds
You can get a concrete guy to give you a foundation any size you want and it should be close to what you want. I'm sure that both of our subs can give anything to within a 1/16" in the lengths. They probably are not quite so good for square, usually within a 1/2" and about the same on the heights. The simpler the foundation, the better they are. If the foundation has many corners and different heights, the accuracy is a little lower.
They appreciate it if the lengths can be made with their forms but they can cut forms for any size. Do they like this? No, but they don't have to. Will you pay more? Yes.
Paul, what's with the 5+"? All your sheet goods come 4'x8', lumber comes 12', you are gonna end up with a whole bunch of little expensive scraps.
The size of the foundation is immaterial, level is critical and give or take 1/2" won't hurt you. Be a bit more specific about your reasons for this size and maybe you'll get a more useful answer.
Not that these answers aren't useful info, but I'm guessing that it's not what you are really after? Joe H
I'm surprised no one has asked what your foundation is made of; all posts are assuming concrete. Around here, Virginia, the most common new construction material in CMU. In that case you would try for masonry dimensions which are increments of 8". 12'-0" or 12'-8". Fractions are for accidents!
Yes, why a dimension of 5" ? Heck, just keep things a little simpler and make it 6", or even the next full foot dimension, or the next EVEN foot. Won't hurt to make a room or two a little larger.
Modules of 2 or 4 feet are very common, certainly with CMU's but also with formed concrete. Must just be the K.I.S.S. principal put to work!
Ken Hill
Everyone,
Thanks for the great input!
With your responses in hand, I met with our designer last night. We went over the drawings and scrutized nearly every dimension and made changes wherever it made sense. Since the house became bigger than originally planned, we simply downsized the odd-ball dimension to the next lower 1-foot increment.
Although this designer is costing a fraction of other designers we interviewed, I thought HE, not I, should have raised the issue with the unusual dimensions. You get what you pay for.
p.s. The foundation will be poured concrete.
There's an advantage to having a "designer" or "architect" that is familiar with the actual nuts and bolts of building.
There may actually be a time when a 9' 3 3/32" wall is required...but normally it's just there because that's what the CAD program spit out. From input made by a designer who may not be familiar with economical framing practices.
A foundation crew is going to shoot for about a quarter-inch tolerance. They can aim for a straight 12' wall, or for a 12' 5 1/2" wall...and they'll come within a quarter-inch of either.
You may pay more for the ambuguous dimension...as well as the wasted materials that go into the ambiguous wall above it...but it can be done.
Try to keep things simple. It sounds likew the changes you made are a step in the right direction. If you can't hit a 2' increment, it's usually best to be slightly less than it. Example...a 7' 11" long wall is usually more economically framed than an 8' 1" wall.
Kind of...<g>