Wood Roof Truss (2 story slope) 4

[Ben29]

I am the EOR for this single-family home. The roof wants to be pre-engineered wood roof trusses, but I do not know exactly how to lay them out. The problem is that the walls on the 2nd floor to not align with the walls below.

It seems to me that everything above (and including) the 2nd floor wants to be part of a roof-truss system. But I am not sure if that is the best thing to do.

I thought about doing an attic truss design to encompass the 2nd floor, but the clear span of the truss would be 48ft. Alternatively, I thought about doing a 3-piece, raised center bay truss. But I have never specified that before and I have only seen it online.

I have been staring at this for too long and I would appreciate any advice!

 

[1503-44]

Wood truss rule of thumb for floor trusses is 1" height per foot of span. Will you use only roof trusses?

It would help a lot if you could straighten some of those red lines.

 

[Ron247]

It does not look like a good application of trusses. Looks more like stick-built because of trying to have more open rooms than classical truss. You can do it with trusses but you will probably wind up with several different truss systems combined.

The roof wants to be pre-engineered wood roof trusses

I assume you mean you or the Owner wants pre-engineered. Why?

 

[1503-44]

I agree. The cost savings with trusses comes with using the same configurations. Cost efficiency is lost by having to set up different cuts and jigs for multiple types.

 

[Ben29]

Architect suggested trusses from the beginning, That is how I wrote my proposal. My fee is very low (owner beat it down to below 1k), And I rationalized that using trusses eliminated alot of work for me.

I originally said that I was EOR, but really I am just providing redline markups for the architect and he is signing the drawings.

If I do stick frame, that is fine. But I will still have the issue of no bearing walls below the 2nd floor walls.

Thank you for your input.

 

[NorthCivil]

Not sure of your location, but getting involved in a job for less than 1K doesnt do anybody any good.

I will drive somewhere and take a phone call, but as soon as I have to write something, 1500 is the minimum to get involved for anything due to liability and admin costs alone. That might be looking at a rotten post or something of that nature, not design of an entire building.

 

[r13]

Post the building side view may help in better understanding of the issues.

 

[dhengr]

Ben29:
Ugly and difficult structural framing too, all in one building. Some Archs./Designers are really over achievers, thinking they are doing great design, and then wonder why their bldgs. are so expensive. Have the Arch. and truss designer/supplier work out the framing and provide all truss reactions and their locations. Have the Arch. show the values, connection details and locations on the plans, circled in red, and you’ll design some posts for those conditions.

 

[Ben29]

@r13... this is for you

 

[r13]

Pretty. Thanks (early present for X'mas , I don't think $1000 pay for the troubles, unless the truss design is delegated.

 

[Ben29]

Thank you, dhengr, that is good advice. And thank you for sympathizing.

 

[KootK]

Heavy Red = Probably Girder Trusses
Heavy Black = Steel / Wood Beams as Required
Blue Dots = Posts Not in Bearing Walls
Grey Rectangles = Bearing Walls

1) I was a truss designer in college and for a couple of years before that.

2) Even if every truss is a different profile, the pre-engineered trusses will be substantially cheaper than stick framing in most parts of North America.

3) You'll likely need a handful of beams and posts. It's not a 100% "by others" roof and floor system. That said, it's easily a 90% "by others" roof and floor system.

4) This is a building that can, and in my opinion should, be planned out by the EOR if we're going to continue pretending that we have reasons to exist.

 

[MIStructE_IRE]

You’re doing structural design for the entire house for $1,000?!

I thought my fees were low!

 

[Ben29]

@KootK, where should I send your check?

 

[KootK]

Stick frame residential can be a fee nightmare. I've seen as low as 0.25/sf for some stuff with only markups to arch drawings. Hopefully this one falls into a jurisdiction where detailed lateral design isn't required as that could get ugly too.

 

[KootK]

@Ben29: I'll accept future good will as remuneration.

 

[Ben29]

@r13, you do deserve a tip! I will send you a gift card to Blockbuster Video.

 

[r13]

Appreciate

 

[1503-44]

KootK... find some way to publish your phone number. Future good will is going to generate a of work coming your way.

 

[NorthCivil]

KootK you are nuts for doing this for free online. But i think its better to do it for free, than do it for cheap.