Steel I beam--Will it hold up one side of my house?

[Erin]

Okay, please don't hang up on my lousy sketch.  It's just for the rough idea so I can ask my question.

(shop side)                            (garage side)

This is the basic picture of our main floor.  40' long x 32' wide.  Standard gable ends.  THe white is a porch area. 
I'm stuck in the design process.
Below it I want a daylight basement for my online fabric shop (it's done nothing but grow since I opened!)
One half will be the store (under the porch half).  The other half will be a two car garage that can someday be converted into a large space for some yet-to-be-determined use. 

What hanging me up in how do I support my posts?  Particularly any interior ones...
Obviously the best way is to put supports directly under the posts.  But there's no way to do that with an open spanned garage.  I really don't want to have to go back to stick framing now that I've found a post & beam method that I really like...

Is there some way around this?  What am I not seeing?

We have half a dozen steel I-beams, 6"x15"x 30 feet long...

[firefox]

What is he weight per foot of the I beams. I believe this will be needed to calculate the load they can carry, also what is the thickness of the flange?  Hopefully someone has some tables and can tell you.
Bruce

[glenn kangiser]

It's possible, Erin.  It's generally calced by engineers though and if you need permits, it will for sure have to be.  Other than that we can probably find a table to give you an idea.

[Erin]

I don't need permits beyond the septic.  Our county doesn't care if our house caves in around our ears.   

And yeah, we're going to run anything we finally end up with past an engineer. 
But I really want to have the final draft ready so that we can basically put it in front of him and ask, "Will this work?" rather than "how should we do this?"
Know what I mean?

[PEG688]

  You could figure it all out BUT the Engineer will have other ideas I'm sure.

I'd say just give him the basics , length , heights ,  etc ALONG with the part about the steel you have on hand. He'll also want the spec's on the steel you have , beyond the basic size. He'll need weight per foot , any FACTS you have about the steel , age , is it rusted , has it ever been used before , been involved in any fires,  etc , etc.

The Engineer needs all the facts , or he'd not be able to figure out what it's capable of.     



   



   

[MountainDon]

If you design what you want, ie, the length of the span and the building above it, the engineer will size the steel beam according to the weight it needs to carry.

[mvk]

Erin

Are you working with a post and beam guy? Most of them around here use steel sometimes so they should be able to help with that.

In the old days you would just call the steel company and their engineers would tell you what you need but you needed specific spans and what was above. Most post and beam guys around here work with 12'x12' units, once you get over that you get expensive. So you see a lot of 24'x36',48' basic houses with additions like L's. Of course the really high end houses do what they want.

Do you have 2 floors and a basement? It looks like you are working with 10' units one way 40'/10' but what about the other way 32/2=16'. were you thinking 16' 2x12 joists under first floor or traditional girts, summer, joists? Seems like a waste for a garage ceiling. Were you thinking of a line of posts down the middle at 16' on 10' centers. I don't know how you would get away with out some kind of center bearing wall on first floor.

From your drawing it looks like you were thinking of a 20'x32' open area for the garage? How about your shop, will you have a bearing wall in the middle of that 20'x 32' space. Are you going to have 2 9' garage doors?

Do you guys weld or know some one that does? Can you cut that steel? Some one asked how thick is your steel I would guess at lest 5/16", more likely 3/8"?

I see 2 main considerations if you were going to build with a center bearing wall at 16' 1. that first post in the middle on the first floor, and transffering weight to the ground 2. carrying the first floor joists that would span the 20' of the open garage.

I used to love to do stuff like this.

FWIW this is what I would do if I had to do this and assuming the steel was good and it's what I outlined above with just the garage clear span, not the shop. I would use 3 beams at the center 16' in side by side and weld plates across the top and bottom to tie them together maybe 12" to 16" on center with a extra one where the post would sit. I would then use 2 more beams at half way between the center beam and outside wall. That would give you joists that were a little less then 8'. I would put posts under the beams in the wall between the shop/garage so you would need footers poured for them a bigger one under the 3 beams. You would need beam pockets in your concrete wall. I might consider a Lolly column or 3 under the 3 beams with a bigger footer there also. or see if the concrete guy would thicken the wall there. You could use your last beam on the out side wall as a header or go with wood since you only have a 9' span for the doors. This is all kind of messy and if you don't do it your self could cost a lot. Anytime you try to clear span it usally does.

I think this would be fine, probably would only need 2 beams in the middle but maybe I'm totally off the wall . I'm sure someone will let me know. Maybe someone could do the math. If this was my place I sure wouldn't worry about it falling down. But then maybe it's people like me who make other people think they need building codes. Still a lot of barns and a few covered bridges around here that wouldn't pass any inspections

I would for sure find a local pro who you know or is recommended before you followed anything I said!

Wish I had those 6 beams.

Mike

[Erin]

Thanks for the replies, guys.

Mike
What's a "Post and beam" guy?
And actually, we're going to aim for 8'oc units (yeah, my posts are too few on both sides) so as to manufacture our own stress skinned panels for wrap.
We're doing a floor and a half (living space in the loft/attic) and the basement. 

The garage side is going to be 20w x 24l (Planning to have store rooms on the back/north wall.)
I've been intending to use floor trusses of some sort to have the large span in the garage, but that's part of what makes me wonder so far as any posts on the main floor...

Yeah, I think our I beams are 3/8" (I'm not going to go out and check today as we're in the midst of a blizzard! In May!  lol) and yes, DH is a good fabricator, so both welding and cutting are no problem. 

Garage doors are either going to be a double, or a two 8' singles.  The store side can be divvied up with posts with no problems, so it's really only the garage side that's throwing me. 
(And we've actually got  a dozen beams, it's just the other six have flaws. )

[mvk]

Erin
A post and beam guy is just a timber framer most of them have some engineering skills. A lot of them act as general contractors for there timber frame's. Most people don't want to spend the money for a timber frame floor in the basement so the do conventional joists. Sometimes the encounter a situation such as yours where someone wants larger spans and they use steel. If you where having your frame made I thought you could ask them.

I now remember you were going to make your on SIP panels, based on a book by Alex Wade, I used to have one of his books 25 small house's or something tried to find it tonight must be one of the books I lent to someone. I remember he used small frames with metal plates, quick and easy and don't need the skill of traditional timber framing. I had some interest in this. Would like to know how you are going to build them.

Mike

[Erin]

I remember he used small frames with metal plates, quick and easy and don't need the skill of traditional timber framing

Yep, that's what we're aiming for. But who knows if that's what we'll end up going with for sure.  Two years ago I was positive I wanted straw bale.