What did your co-worker say on the matters. I wasn't there to know what was said.

What's did he/she say about the change in philosophy of documenting?

so in Ricki's imaginary problem he jacked from his word doc that he copied from another website.

10'x15' = 15' x 50 psf (live load) and now let's see if Timber is even useful here.  Remember Ricki forgot to describe the dead loads because this was all whipped out of thin air to begin with...  With an allowable deflection of 1/240 I could save your client money with (2) 2x12's since there is no sheathing or anything, and some deflection ain't bad when you have neither flooring or ceiling. I'm slightly over the allowable here, but again since this is random copy paste time, who cares about context (that calc took 2 minutes btw - it's called Excel)

What Richard Balkins lacks is the capacity to understand problems and their application.

So I did Ricki' job with Lumber, not timber he googled and found in Virginia, considering he is in Oregon.

and what the fuck does this have to do with John Wick. 

why 50 psf live load, what occupancy is that Richard?

Olaf,

I'm operating on longevity and endurance factor of the structural systems. (2) 2x12 might work (not as a primary beam but under a smaller tributary area) if you have no fire rated sheathing but structural systems needs to be fire rated with a fire rated assembly. This also means you will want to keep the deflection to a minimum. You also have to remember that wood does lose its strength over time eventually.

You also need to pay attention to the fact that for performance sake, you don't want the beams to deflect more than the floor itself you are supporting. Lets say you have floor joists. The structural or primary structural system should deflect equal to or less than secondary structural systems. When floors have to be l/360 then you want it to perform. Even though I can go the minimum size in the span table, I go up one or two. The reason is wood joists (solid hewn / conventional lumber) has imperfections) may have imperfections not noticed under visual grading as the lumber is typically graded. 

One reason to go up a size notch above the minimum is that you need to also consider things like possible holes being drilled into the joist for pipes and electrical. In an ideal world, this never happens but this isn't an ideal world, is it?

The saving money you make now can cost them their lives. Right? 

l/240 typically results in people complaining the floor is a bouncy floor. Lets consider the deflection over span. For example a floor joists spanning 17 ft. You wouldn't want the joists under load to sag more than 1/2" at mid span or at any maximum concentrated load point. Ideally, sag would not be more than a 1/4" or more than 3/8" at mid-point over this kind of span. For dead load, I calculated 20 psf but lets consider that 20 psf might be a little light and in reality, it might be a tad more. Lets assume you are using a floor joist on top of the beam at 16" o.c. Therefore, 20 psf is probably closer to mark than 10 psf. Lets not forget you probably also have mechanical ducts and stuff like that as well. It might actually be 30 psf. 

I would probably go with 4x12, 2x14 or 4x14. While a 3x12 (or double 2x12s) would be the sweet spot. The beams on the other hand would be at least 8 x 16 but probably 12x16 as I want sufficient thickness to depth ration for competent columns underneath to support the beams.  You don't see 3x members so often these days so I could go 4x members. They are more common than 3x. Sure, you can use a built-up beam (not talking glulams) that is nailed together along with glue-bonded. However, they may or may not necessarily be up to 100% equivalent to the solid lumber in reality so you want to make sure you aren't too close to the calculated minimums. 

Yes, an excel spreadsheets exists that can use to derive these numbers but so what. The B.O. would expect to see the math on how you derive your figures not just a computer generated spit out from a printer. Do you know the equations, if I were to ask you off the cuff at a random....? Probably not. Don't fret, it isn't something we would remember like that, is it? Okay. As for the math equations, it's there to determine that. 

While I could have manually calculated the weight of the material (add 1-2% for nails/screws and other fasteners and joist hangers.) or I can just be a little bit whimsical here with some raw guesstimate of the weight and leave a little room by going up a notch or two on the size required. If you want the structure to perform uniformally, you try not to get too far apart. You want to have structural mechanical uniformity to some degree. In addition, you need to consider endurance factor. 

While your (2) 2x12s might work for a transverse beam but it probably only only going to work for joists but it would be far too bouncy and problematic for carrying the actual beams. I was talking about beams with a tributary load of 7,500 psf of live load plus a dead load of maybe 20-30 psf. Assuming a highest level of of load being around 80 psf. This would be around 12,000 psf on the beams. 

Since you don't want your floors to feel bouncy or even have perceptible sag over span. Lets assume you have a floor that spans 10-ft. (imagine a hallway that's 10-ft. wide). That hallway. On each side of the hallway has columns every 15-ft. on both sides. The joists are spanning across the top. I would probably say these joists would be 2x14s @16" o.c. or even 4x12s if I want to not have to apply cross bracings. Since spans of 10-ft. across a hallway isn't too extreme. The load on that is probably not that bad. I could use 2x10s for joists but if the spans are to go beyond that... say.... hallways of 18-ft. width. You would want 2x14 or 4x14.

Don't forget, there is probably classrooms on both sides of the hallways. 

The beams we are talking about is supporting these joists that forms the ceiling structure above the hallway. Lets not forget it is probably going to be having a 1-hr rated ceiling. It probably also has an HVAC mechanical systems, some light fixtures and some electrical conduits and oh lets not forget fire sprinklers while we are at it. These beams and component columns (12x12s or possibly 12x16 posts columns) to support them, can't be minimal load.

Hallways will get heavy peak loads at moments in the day, you want them to perform well and you don't want them to feel bouncy causing alarm to people. 

As you would notice in actually calculating, a (2) 2x12s won't span 15 ft. It won't span even 10-ft. even with SS if you have any dead load factored in except with a few species of wood that might pull that off. You would need to increase number of columns to make it work. You can surely do that but you may that is a debate of design. On the safe side, you would not want to span more than 8'-0" o.c. This gives you a few options of lumber grade but I would probably not even span more than 7'-6" so as to give you and the contractor options of lumber grade from No.2 and up. 

In short, using double 2x12s to support a 150 sq.ft. tributary area (10'x15') with 50 psf live load and say 20-30 psf dead load. It would fail to pass even l/180 deflection standards. It would likely result in a structural collapse unless you reduce the span by adding more columns. Cutting the span in half, you can do it adequately.

If I had to tell you what typical dead load to factor for, you are kind of ridiculous. The choice of 12x16 does allow for some additional load. The choice of using 4x14 would allow for some additional dead load conditions or TLs (total loads) greater than 80 psf. 

On the ground level, I would probably use a concrete floor system. At times, you apply additional measures for structural stability, endurance, performance and so forth. 

NOW, LETS USE THE CORRECT LIVE LOAD FOR SCHOOLS (CORRIDORS/HALLWAYS):

Now, the code requires 80 psf for hallways (corridors) in schools. The reason I would go with 4x14 makes sense. 2x14 can be used but a 4x14 gives some extra room in the structural design for a TL of 110 psf. 4x14 would allow spans over 20+ ft. My calculations and sizing still holds up for the proper load values from the code. The biggest bitch in the sizing is the concentrated load. 12x16 is probably about the limit but this requires some healthy calculating to determine cross section. While the 4x14's still holds up. The 12x16 is still probably up to snuff. From some WWPA properties values for Douglas-Fir, it still holds up even to concentrated load values. 

Passing deflection. Passing horizontal shear. Passing section modulus. You can say that is passes even with a TL of 200 psf or 2000 plf. 

While in schools, the classrooms will have a 40 psf live load with 1000 pound concentrated load over which averages out to 160 psf. In some instances, colleges maybe required to meet an even higher requirement depending on whether requirements from Office is being applied or Schools under Chapter 16. This can be an interpretation matter as colleges maybe deemed Group B vs. Group E Occupancy. While Chapter 16 load should be viewed not based exactly on Occupancy classification so it's a code debatable argument with the BCO. 

As we look through the code, it is often a bit on interpretation. There is some degree of interpretation and we aren't always right. 

From my experience, you want to make sure what you designed meets the standards.

While I tricked you on the 50 psf. Hallways are 50 psf. Classrooms for schools are typically 40 psf or 1000# concentrated load over a 6.25 sq.ft. area unit (uniformally discerned as about 160 psf but don't forget to combined dead load as you should. I load the figures to 200 psf for 1000# concentrated load and some substantial dead load.

The joists overlay won't deflect too much but the beam may. However, even under calculation, it is within the l/360 test so as to not over stress drywall that would be used to protect such beams unless you can have sufficient fire resistance rating.

If you are satisfactorily happy with l/240 but I tend to keep things less than that even under peak load figures.

While, I wrote this, I haven't read any other posts after the one quoted.

At this point 12x16 is NOT surfaced. It would be 12" x 16". Otherwise, I would probably take it up to the next size notches up like 12x18 or 12x20. As long as the cross section is 500 or larger that maybe S4S.

why 50 psf live load, what occupancy is that Richard?

For group B occupancy.  For schools, this gets a bit a bit higher for corridors. It all depends on what loads are being applied to the structure. 

50 psf is a fair uniform live load. Concentrated loads can be a bitch depending on the how the load is distributed on the structure. 

i made the spreadsheet in Excel Richard. you are such a dumbass my mind is blown. nice imaginary problem that keeps growing to cover your first imaginary story.......Give up already, you do not have the mental capacity nor character to ever be a successful or even below average architect or building designer. You are wasting your time which clearly is not valuable.

You fucked up the equations. You fucked up on things like material attributes. Just shut up. Give up already, you don't have mental capacity to do anything correctly that humans are suppose to do. 

Now go suck a cock and leave me the fuck alone.

no_form,

You're right. Got dragged into this gutter trash environment on this forum for far too long. Thanks for the reminder. I'll try to work back in restoring those practices again. 

PS: Olaf, double 2x12 just doesn't work for load bearing for most species of wood. There would be excessive deflection if you are carrying full floor load on the beams.

Everyday Intern,

While there are in fact new things and new methods of construction, there are also a lot of the same basic construction systems still in used. For example, we still have platform construction. We still have balloon frame construction. We still have post & beam construction. We still have a lot of the same basic construction. With increase seismic standards, there maybe more requirements for shear resistance designing. For high winds, you may have rafter hold down ties that you implement that wasn't. It may require some modifications of connection detailing but otherwise it is still a lot of the same stuff. 

Architecture today doesn't necessarily require being weird and avante-garde. 

Yes, you adapt with changes but the changes are not always that much. The principles are the same. While we may reinforce connection requirements, a lot remains the SUBSTANTIALLY the same. We may have different products for connecting beams than it was 50+ years ago. There is a lot of the same principles involved. The engineering science behind structural doesn't change. Structural Engineering science is applied physics. 

The fundamental physics science as it applies to structural design/structural engineering sciences hasn't changed for a long time. It is still founded on the same 'Newtonian' physics and that hasn't changed in any significant applicable level for a long time. It is the same principles in the 19th century at the dawn of the Industrial age in the U.S. as it is today.

The science underlying structural engineering is the same fundamental science then as it is now.

Architecture today doesn't necessarily require being weird and avante-garde. 

​Can we just drop the assertion that this is a binary? 
 

tduds, 

Okay. That's fair enough point. 

tduds,

Absolutely. A project is more than just structural considerations but they are important. At some point, you can do a lot of it intuitively because you figure out some general rule of thumbs. As it is probably well known, most structural failure is in connections of components. That is often the weakest link in the structural 'chain'. (metaphor)

tduds,

I don't know what no_form is saying has to do with anything relevant. As for contextual relevance to what you and I were talking about, structural failure and key areas or points of failure is relevant to structural consideration points that are being made.

Yes, in a project, we spend a lot more time on other issues than structural consideration.

I don't think there is an argument there. Should there be?

Schools come in varying sizes. It isn't like I am suggesting a single architect to design a 5 Million sq.ft. 100 stories tall skyscraper.

If you can design hotels and mall buildings, it isn't much of a stretch to design a school building. It isn't that hard for one architect to design 150,000 or 200,000 sq.ft. of buildings. Say, two to three buildings. Each ranging from 45,000 sq.ft. to 100,000 sq.ft. 

I could do that myself if I did't give a shit about architectural licensing laws. The point isn't about whether I can or can't. Architects just don't do such projects because of insurance coverage or fear of the insurance companies. This is because architects rely on them and bound themselves by choice. It was a choice that Architects have taken. In most states, you are not required to carry insurance for licensure. If you do a school project, why would insurance cost be an issue. 

You can complicate design or you can simplify it to manageable level. 

Are you worrying about computer networking? That's not that difficult. You simplify the design using Wifi routers and repeaters. This simplifies the networking diagrams.

As for telephones, that would be concentrated around the school office with its multi-line PBX. These are installed by telephone companies and switchboard manufacturers. 

It's easy enough to design.

It's work. If you make use of natural lighting, you don't need crazy lighting systems. A school would be more complex than a house. That's a given but don't you think we can do this in less than 100 sheets? for each building. Maybe 150 sheets. While a spec book for each building would be there. Of course, copies can be made. I am talking about a single set for two to three buildings not the multiple copies for permits and contractors. We understand that can add up.

You complain about my verbosity. Right? Think about it for plans and specifications. Do we need to be endlessly verbose in a set that no one will ever read through it all. Not even a foreman or site supervisor. It'll takes too damn long to sift through to find the answer. On a job site with construction, you got maybe 5 seconds to find the answer AND communicate it to the person needing the answer like the roof framer. They don't sit around for half an hour sifting through the plans and specification books. They don't have time for that. 

Otherwise, it just sits in the back of a truck or in the shop building collecting dust. That's what I was getting at.

I've heard some here basically proposing these long winded plans and specs.

The foreman would be right outside directing the framers, right? Not in a job trailer.

Clients may want this and that but plans and specifications are to communicate to the builder how to build the buildings but at some point the builder just won't spend all day reading through them. If you ever framed a roof in your life in 80-90 degree weather, you would not sit around waiting all day for someone to sift through the encyclopedia of britainica of plan set. The point is being concise and on-site supervision of the architect.

At some point, no one will use it because it becomes functionally useless. Every minute that the framers are just standing there doing nothing, it is costing the client money. They get paid not by nails they frame into the wall. They get paid by the hours they are there. The more time spent sifting through plans and specifications, the longer the project is going to take to build and the more it is going to cost the client money.

N_S,

Nice trying to read a full set of plans on an iPad in broad sunlight. Yeah, lets not forget you are trying to view 24x36 sheets on a screen that's only about 7.5" x 10" screen. You are only viewing a portion of the plans. It's kind of like trying to view a book through a pea hole.