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  #1  
Old 03-06-2005, 11:11 AM
ralph124c ralph124c is offline
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Post and Beam House With Steel Girders?

I've always dreamed of building a post and beam house-I like them, because you don't need interior load-bearing walls, and I like an open floor plan. However, the price of 8"x8" wooden beams is out of sight..so could i build the house with steel "I" beams? I've never worked with steel-will fabricators drill the beams for youso that you just have to bolt them together? Would I have to hire experienced steel riggers, or is building the fram something I could do myself?
As for finishing the walls-how would you attach wood 2x4 studs to the I beams? =could they be bolted on as well?
Finally, how much do steel I beams cost?Will the town engineer grant approval for this type of construction?
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  #2  
Old 03-06-2005, 03:56 PM
Valgard Valgard is online now
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Could it be done? From an engineering perspective sure thing, if it works for a 100 story skyscraper it'll work for a residence.

However to find out exactly what is involved and whether you can legally do it in your area I think you should start by contacting the building inspector for your city (go down to city hall) to see roughly what rules and regs you'll have to follow and then talk to a qualified architect, engineer or home-builder (someone with actual experience constructing such a dwelling in your area).

I haven't checked recently but when I was getting my civil engineering degree structural steel cost about 50 cents per pound for standard shapes.
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  #3  
Old 03-06-2005, 05:37 PM
LSLGuy LSLGuy is offline
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Where I live steel beams are a common part of house construction. The basement is dug and concrete walls are poured up to grade. Then 1 or 2 steel I beams about 10" tall are laid across the opening lengthwise. Then a conventional wooden joist floor is laid with the joists 90 degrees to the I beams. The effect is to reduce the unsupported span of the joists to be 1/2 or 1/3rd of the short dimension of the footprint. This permits much lighter & cheaper joist structures and/or much larger footprints with the steel costing virtually nothing.

The upper floor(s) are conventional wood stud / beam / joist construction.

If an interior wall is needed in the basement, it can be built up under the I beam and the wooden top plate attached to the underside of the I beam's flange with nailer clips made for that purpose.

It's not true post-and-beam by any stretch, but it shows that steel isn't unheard of in modern residential construction.

I'm not a construction expert, but I've also heard good things about using prefab steel studs & plates. They're universal now in office & retail store construction. The reason they're not used in home construction is a chicken and egg problem. Until the builders are sure people will buy they're afraid to build, and until people have experience buying, steel will seem new & scary, etc. As well, the residential construction workforce isn't skilled in steel yet.

If you're DIYing it, look into steel. Supposedly it's a bunch cheaper/quicker once you have the skill & the tools.
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  #4  
Old 03-06-2005, 06:40 PM
cornflakes cornflakes is online now
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It might be better to let the architect, engineer and/or general contractor pick where to use steel or wood. Steel may help control costs or allow you to span a greater distance. Then again it may not. My guess is that the design will influence which materials work best.

Is this a two story building, or just a one story? If you just need to hold the roof up, regular plated wood trusses can span 40 feet or more. Wooden I-beam joists can span over thirty feet for floors.
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  #5  
Old 03-06-2005, 07:00 PM
a pirahna brother a pirahna brother is offline
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I work for a steel fabricator, so I'll try and answer your questions.

Quote:
I've always dreamed of building a post and beam house-I like them, because you don't need interior load-bearing walls, and I like an open floor plan. However, the price of 8"x8" wooden beams is out of sight..so could i build the house with steel "I" beams?
Sure, why not? We do houses on a regular basis, even though most of our work is in commercial and retail. House work jobs are nice filelr jobs in between the big stuff, and usually the weight makes it worthwhile to do.

Quote:
I've never worked with steel-will fabricators drill the beams for youso that you just have to bolt them together?
Unless you like lots of field welding.

Field bolted is the easiest way to go, talk to your fabricator and see if they can make the frame all bolted, it may depend on the design of the structure and what you're willing to pay. If it's cheaper for you to field bolt than field weld, then do it, but it may be cheaper to weld a few things than have the fabricator make connections to bolt everything.

Quote:
Would I have to hire experienced steel riggers, or is building the fram something I could do myself?
Talk to your fabricator, they probably know of local contractors that do this type of work.
With the weights involved in steel construction, if you're not experienced, you can get yourself hurt or killed.

Quote:
As for finishing the walls-how would you attach wood 2x4 studs to the I beams? =could they be bolted on as well?
What we've done is punch a series of holes to fit a dia. bolt about 24" on center, staggered from side to side, so you can bolt a 2x for a nailer, then you can skin the beam in wood or drywall, when finished, you'll probably never guess there's anything steel behind the finish.

Quote:
Finally, how much do steel I beams cost?
Fabricated steel runs 75 to $1.00 a pound easy, really odd stuff can go higher, but this is an average range.
Our material prices are high right now, a lot of items have doubled in price from last year, be forewarned, most fabricators will only hold a quote 15-30 days at most, don't get pressured to sign now, but don't wait 2 months either.

Quote:
Will the town engineer grant approval for this type of construction?
Can't say for certain, but in my experience, the engineer will probably want a structural plan stamped by a Professional Engineer registered in your state, and he may want a plan by a Registered Architect as well.
Talk to the engineer before you go anywhere with this, find out what he wants before you do anything, then find people that can provide what he wants.

In closing, talk to your fabricator, after talking to the town engineer, a fabricator should be your next stop. Find one that has been in business at least 10 years, longer if at all possible. The company I work for has been in business for 38 years, and we've done a lot of different jobs over thse years.
A good fabricator will have the experience doing this type of work, I deal with homeowners like yourself on a regualr basis, and most of them come in with a "I don't know what I'm doing" look on their face, but once they've met with us and we've explained what they have to do, they usually relax and realize it's not as hard as it looks.

If you have any more questions, my email is in the profile.
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  #6  
Old 03-07-2005, 10:10 AM
cantara cantara is offline
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Speak to an engineer or architect. They should be (had better be) familiar with the building code in your area. They should also have the contacts and have a good idea about the relative costs, benefits and alternatives.

IANAArchitect, but my dad is and I've heard him talk about different scenarios. One of his peeves is people coming to him and asking him to design a Georgian style house. His reaction is to send them to an engineer who will already have that type of plan in their portfolio rather than spending the money on a custom design that looks like other houses. After the architect makes the design, he still has to consult with an engineer to ensure that all the loads are acceptable and must be signed off before going to get the permit from the municipality.
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  #7  
Old 03-07-2005, 03:20 PM
Can Handle the Truth Can Handle the Truth is offline
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You would be better off using LVL (Laminated Veneer Lumber) Beams. They are an engineered wood beam that comes in sizes up to 24" deep and are much stronger than natural wood beams. Here's some info from Georgia-Pacific.
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  #8  
Old 03-07-2005, 06:05 PM
SavageNarce SavageNarce is offline
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I will give you one caveat: Steel beams are plenty strong and rigid...unless they are in a fire, when they lose their strength and rigidity alarmingly easily. Therefore most (all?) building codes require the steel elements to be encased in a fire-retardant material such as drywall. Steel elements can be sprayed with insulation in situ for a similar effect, but not if they are in a situation where the insulation might be subject to being shaken off, rubbed or worn. So a true "post and beam" construction (where the steel elements would be visible) is probably not going to be approved by the building inspectors. But a concealed steel skeleton, covered with something like drywall, would be acceptable and, as Valgard said, is the basis for a good proportion of commercial high-rise construction.
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  #9  
Old 03-08-2005, 07:27 PM
a pirahna brother a pirahna brother is offline
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Fabricator checking in again, I thought I'd add some more information to this thread.

SavageNarce is right about steel beams losing their strength in a fire, but consider that if you were in a house fire this hot, you would probably be dead from smoke inhalation.

Page 14 from this document, warning PDF file
AISC Publication on Fire and Steel Buildings
According to the American Institute for Steel Construction (AISC), steel retains approximately 50% of its strength and stiffness at 1100F, a 20% strength retention at 1300F, and a near total loss of strength at 2200F.
Incidentally, the melting point of steel is 2700F, which is considered impossible to reach in a "normal" structure fire.

Not all steel structures have to be fire proofed or encased, Wal-Mart, Home Depot and various "big-box" type stores usually have fire sprinklers, but the steel items are normally painted and do not have any form of fire proofing. Page 23 of the linked document mentions that sprinklers are allowed to be substituted in lieu of 1-hour fire ratings.

I won't get into all the nuances of the code, only a local engineer and/or architect can tell you if your structure will qualify, but I will note that fire ratings and protection methods depend on the tpye of structure, the number of human occupants, the egress methods, the height of the building above what local fire equipment can reach, materials used in the building, et al.

An idea for something that looks like traditional post and beam construction would be to use steel tubes painted with an intumescent paint, IF the local building codes will allow it, I can't say yes or no.

An intumescent paint is a type of paint that swells and forms a char layer upon exposure to fire, threby protecting the steel.
Here's a company that manufactures this type of paint:
http://www.albi.com/cladtf.html

Quote:
Posted by SavageNarce
But a concealed steel skeleton, covered with something like drywall, would be acceptable and, as Valgard said, is the basis for a good proportion of commercial high-rise construction.
I feel I must correct this, I'm not trying to be snippy, but I do this type of work for a living.
In high rise construction, per page 22 of the linked AISC document, 2nd full paragraph on the left column, where high rise is defined as having an occupied floor 75 feet above the lowest level of fire vehicle access, automatic fire sprinklers are required.

To repeat what I posted first, talk to the town engineer first, see if they will allow this type of construction, then you need to talk to an engineer licensed in your area, you also need to talk to a fabricator as well.
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