Back to the drawing board...can't get trusses to remote location


SkullMesaRanch
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I had my first construction document review with the county and was almost done with my plans. 

 

So here I am asking for design advise.  As far as I know you can't use roof rafters for this span. l really didn't want to build a territorial home with a flat roof but it looks like that might be my only option.  I'd like to have a pitched front porch tiled overhang.  Does anyone have an example of this?  Any advise related to this subject would be highly appreciated.

 

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It might be worth having a discussion with the neighbors.  They might be happy the road is going to see some improvements.

 

A 20 minute helicopter ride may be an option....

 

Or check with the truss supplier and they may be able to supply the engineering for I joists if they sell those as well.

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Have you considered Truss Joist Rafters? I am not sure of your layout and whether there are large open spaces but you can site build some beefy ridge beams by connecting Versalam pieces. I had my last project with (3) 1.75" x 16" versa lam beams. I wanted to break it into 3 pieces so we could construct it without a larger crew and a crane was not an option.

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On 9/21/2023 at 8:49 AM, Chopsaw said:

It might be worth having a discussion with the neighbors.  They might be happy the road is going to see some improvements.

 

A 20 minute helicopter ride may be an option....

 

Or check with the truss supplier and they may be able to supply the engineering for I joists if they sell those as well.

 

 

The lumber supplier didn't give me any options but I also didn't ask.  They definitely don't build trusses on site.  I'll check with them and find out more about a roof I joist structure. I was going to use energy heal trusses so they sat on top of the porch beams.  Can you have a boxed eave with an I joist structure?

 

 

 

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You can do almost anything with an I joist system. Think anything you can do with solid sawn lumber but now you have larger spans with lighter material that is super consistent and can be drilled out with crazy large holes. There are a multitude of instructional videos on installation as well as drawn/illustrated details.

 

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2 hours ago, SHCanada2 said:

..beam and parrallel chord truss. cut the truss length by half

Thanks for the input.   This would be beneficial if I wanted vaulted ceilings.   The back and front porches could have a lesser slope and therefore cut down the length of the truss.  The maximum length between bearing walls is 35'.    I'll try post my plan but usually have problems.

parallel chord truss.png

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On 9/21/2023 at 11:51 AM, solver said:

This is an older version of the plan you had posted. Why not split the trusses and have them land on a bearing wall?

 

 

 

 

 

The only reason I picked trusses was to make the design and build easy.   Using a flat roof with parapet wall is starting to sound a lot easier.  I'm already using a ductless HVAC system (mini splits) so it's not like I need the space for anything.   

 

Is it relatively simple to delete the roof and add the 2nd floor for a Santa Fe style home and barn?

 

 

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Post the plan, give us your roof load specs for snow and live, and someone, me included, will show you how to truss it.  Make sure we get the barn, too.

 

In the mean time, get your supplier's field guy to visit your site and scope out the delivery situation.  I just did an i-joist roof frame in snow country with 110 psf ground snow load, but we have no saguaros here, only huge white pines.  One lane curvy road going to.  Driveway impossible turn.

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I essentially agree with Eric with an important variable. Split the trusses and connect on site. The major difference is the truss sections do not have to sit on bearing. The truss can be designed to be spliced on site either on the ground or during erection. The truss sections must be designed as one truss and the stresses on the splice addressed. Any truss designer should be able to accommodate this. The assembled truss only needs bearing at the "end" points - in your case 48' ± They can design the truss in multiple sections though this is far more complex but very doable. Have done many times over my career. Think about it - they're not using 48' sticks at the fabricator, they're splicing the chords some where. Anyway it's really not difficult, still easier than stick building with dimensional or TJI and you'll get what you want. Here's a relevant part of an article from Structural Building Components from 10 years ago

Trusses that are too long or too tall for delivery to the jobsite in one piece are designed to be delivered in two or more parts, and then field spliced together on the jobsite. Splicing can be performed on the ground before installation or the Truss sections can be supported by temporary shoring after being hoisted into place and the splices installed from a safe working surface. Temporary Lateral Restraint and Diagonal Bracing must be installed per the recommendations provided 

Connections - Field Splices | Structural Building Components ...            Same principles apply to a horizontal bottom chord

Field Splices

Understand the best way to design a field splice to save time and money.

Field splices provide a means of connecting two truss sections together at the jobsite to create a single larger and/or deeper component. The goal of field splicing is to allow truss manufacturing, shipping and installation greater flexibility in serving customer needs. To successfully use field splices on a project, however, there are a number of issues to consider during the design and installation phase.

Common Materials Used for Field Splices

field-spliced scissors trussesIf connection forces and deflections are low, plywood or oriented strand board (OSB) gussets provide a flexible and cost-effective field splice option. One advantage of using plywood or OSB is that the material can easily be cut to the shape needed. For any field splice, make sure the splice material and its connection to the truss have adequate strength to resist the maximum forces that will transfer through the splice. (See photo: Example of field-spliced scissors trusses.)

Lumber scabs used as field splice material provide an easy option if it is possible to make the splice at a suitable location. Lumber scabs can often be used with high pitch scissors trusses if the splice location can be shifted away from the peak. In these instances, the truss is spliced by applying lumber scabs across the splice joint parallel to the top and bottom chord. The long available lengths and ease of installation make lumber scabs a very effective choice.

Metal plate connected wood scab trusses provide an excellent alternative as field splice material, especially when the forces to be transferred through the splice are very large. Scab trusses are designed to transfer the forces across the splice and should match the profile and configuration of the trusses being connected. Attaching the scab truss(es) to the spliced trusses through the aligning members provides a strong and stable splice connection.

Field splices using steel plates with bolted connections are another possibility, although they are far less common due to the relatively high cost of ordering custom plates. Benefits of using steel plates include the ability to withstand and transfer very high forces and relatively easy installation. 

Common Errors with Field Splices: Design Department

steeply pitched scissors truss requiring a specially designed field splice at the top and bottom peak jointsA common error when designing trusses that will be spliced in the field is designing each part as an individual truss instead of as a single truss covering the entire span. Designing the trusses as individual parts typically results in truss members and connector plates that are undersized for the loads and forces that will be resisted by the completed field-spliced truss.

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On 9/21/2023 at 1:56 PM, solver said:

 

I don't understand. When I said wall, I assumed you would substitute beam for the opening between the living and kitchen, and that you would understand that the red line I marked does not need to be straight all the way across the house.

 

You need to sit with the truss manufacturer and explain the delivery issues, and let them design the trusses to fit -- they do that for a living. Your lumber company does not.

 

If you switch to a low slope (flat) roof, most will use trusses with the top cord sloped, and they will still need to be delivered.

 

I use Ballard Truss. They started local to me, but I believe they have locations around the state, and there are surely others.

 

Truss manufacturers often use extendable trailers for delivery instead of a standard semi trailer.

 

And consider asking for a plan review before you get too far. https://www.houzz.com/discussions/building-a-home is a good place.

If you make no other changes, could you flip the hall bath so you are not looking directly in from the living room?

I'll suggest this entire part of the plan could use a good rethink. 

 

1203158856_ct1.thumb.png.c746113781962b1dcbe2b7425414fe76.png

 

 

All other points are valid and very helpful.  I talked with Alliance Truss and they're the ones that said they'd use a semi truck.  Ballard is in Mesa but I will talk to them. 

 

 

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15 hours ago, GeneDavis said:

Post the plan, give us your roof load specs for snow and live, and someone, me included, will show you how to truss it.  Make sure we get the barn, too.

 

In the mean time, get your supplier's field guy to visit your site and scope out the delivery situation.  I just did an i-joist roof frame in snow country with 110 psf ground snow load, but we have no saguaros here, only huge white pines.  One lane curvy road going to.  Driveway impossible turn.

I have someone coming today to work on my internet connection.   Wasn't able to upload the plan this morning.  Will try again later.  I'm overwhelmed with the help I'm getting here.  Thank you everyone,  Beth

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Have you entertained the possibility of staging the trusses and bringing them in by different means? (Of course the viability of that option depends on the distance from the impassible portion or road to building site.)

An example... using a material tele-handler to transport them from a staging area may end up less than the additional design cost and likely the additional truss assembly labor.

Most units have significant load rating to carry in a number of trusses at once and the boom can extend and lift to clear obstacles.

One challenge.. the trusses need to be on angle from 1:00 to 7:00 or 11:00 to 5:00 when perpendicular is not an option due to tight locations.

 

Here is an example site that was an extremely rugged lake lot and tree preservation was a goal. This required staging the truss delivery away from the site and using a telehandler. (it was impossible to avoid potential compression of all tree roots) It was a dance but home owners appreciated the effort to maintain as much as possible.

rugged site access.jpg

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  • 4 weeks later...
On 9/21/2023 at 7:15 PM, richoffan said:

I essentially agree with Eric with an important variable. Split the trusses and connect on site. The major difference is the truss sections do not have to sit on bearing. The truss can be designed to be spliced on site either on the ground or during erection. The truss sections must be designed as one truss and the stresses on the splice addressed. Any truss designer should be able to accommodate this. The assembled truss only needs bearing at the "end" points - in your case 48' ± They can design the truss in multiple sections though this is far more complex but very doable. Have done many times over my career. Think about it - they're not using 48' sticks at the fabricator, they're splicing the chords some where. Anyway it's really not difficult, still easier than stick building with dimensional or TJI and you'll get what you want.

 

I

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